Persistent Storage: What Does it Really Mean?

[Jason Dunn]

Remember <a href="http://www.pocketpcthoughts.com/articles.php?action=expand,34854">that column I wrote</a> late last year? Here's a quote from it:<br /><br /><i>"Ever wondered why many of the new high-end Pocket PCs come with twice as much Flash ROM as RAM? Here's why: Flash ROM, while slower than RAM, is permanent storage – meaning that if your device loses power, the apps/data in Flash ROM are still safe. Current Pocket PCs still use RAM for database and registry storage, so losing power will still put you in a world of hurt. If you look at the way Windows Mobile Smartphones work you can see where this might all be headed: everything will be in Flash ROM, and devices can come out of a battery-dead state without a hiccup."</i><br /><br />I caught a lot of flack for that article because I was essentially stating that 64 MB of RAM was good enough for most people - what I couldn't do more than hint at was what you all learned today about Windows Mobile 5 (and something I've known for a while): persistent storage completely changes the way devices work with memory. Pocket PCs will now work the way they should have from the beginning. Just like on your desktop computer, RAM is used purely for executing programs. Storage will be purely the Flash ROM, and nary the twain shall meet. Suddenly that Dell Axim X50v with 128 MB of Flash ROM and only 64 MB of RAM makes sense, doesn't it? 64 MB is a good amount of execution space - most applications need between one and two MB of space to run, with some of the bigger games needing 10 MB or so. 64 MB of pure application execution space will go a lot further than the 25 MB or so that most of us have after a soft reset. Sweet! :D<br /><br />Another key advantage of this change is Pocket PCs will be a full "off" mode, one where zero power is used. While they're in off mode things like alarms won't work, but that also means you can leave it in your desk drawer for a month and it will still have juice when you fire it up again. <br /><br />This is all "on paper" for the moment - I haven't seen any new Windows Mobile 5-based devices yet, but if my understanding of the persistent storage implementation is correct, this is a big step forward for our beloved Pocket PCs. I'm really looking forward to the new Windows Mobile 5 devices!

[surur]

But of course one can never have enough memory. Have you ever tried to load a Fark thread at infinty on your pocketpc with pictures on?

Non-volatile Ram can be added easily via SD card. Execution Ram is much harder to add. 128MB will still be on my list.

Surur

[entropy1980]

While they're in off mode things like alarms won't work

Umm how is this a good thing?! BIG problem if this is true!

[applejosh]

I'm guessing that "off" mode will be a deep off mode while most of us will still use the suspend type thing. (Completely guessing here, but I don't see how even that would slip past the MS developers.)

[Jason Dunn]

Umm how is this a good thing?! BIG problem if this is true!

Ok, so I can tell you've never used a Smartphone before. ;-) You never turn your Smartphone off if you want it to ring, chime alarms, etc. If you turn it OFF, it's the same as pulling the battery out. So of course alarms aren't going to work - it's OFF. Current Pocket PCs don't have an OFF mode - they have a SUSPEND mode. So this isn't taking away what we already have now, it's adding a feature that Smartphones already have. Makes sense?

[entropy1980]

Ok, so I can tell you've never used a Smartphone before. ;-) You never turn your Smartphone off if you want it to ring, chime alarms, etc. If you turn it OFF, it's the same as pulling the battery out. So of course alarms aren't going to work - it's OFF. Current Pocket PCs don't have an OFF mode - they have a SUSPEND mode. So this isn't taking away what we already have now, it's adding a feature that Smartphones already have. Makes sense?

Actually I have used and own several Smartphones. That makes sense I was equating Suspend = OFF . For instance: I don't put my Pocket PC in "suspend mode" I turn it off. But really it's suspended. I understand that but it just sounded funny. I think most people equate with what I am saying. If the screen is off people assume that means it's off, not in suspend mode, unless it's a phone which shuts the screen off yet still maintains network connectivity which is totally different that current Pocket PC's which lose connectivty when you put them in "suspend mode".

[Jason Dunn]

That makes sense I was equating Suspend = OFF . For instance: I don't put my Pocket PC in "suspend mode" I turn it off. But really it's suspended. I understand that but it just sounded funny. I think most people equate with what I am saying.

If it's implemented in such a way that pressing the power button puts it into suspend and pressing and holding the power button turns the device off, I think this is a moot point. It won't be as big of a hurdle as you think it will be. ;-)

[gibson042]

128 MB ROM and 64 MB RAM is a logical storage arrangement under the new memory management scheme, but the point many of us have been raising for a long time is that it is still insufficient for power users. Movies, map data, large web pages, complex documents, sophisticated games... all are memory hogs and can very easily exceed 64 MB, even with intelligent garbage collection. High end devices should still have at least 128 MB of RAM for these applications. 128 MB of RAM under WM5 will be more memory than 128 MB of RAM under earlier releases, but I consider that to be a much-needed bug fix. :twisted:

[mmidgley]

gee, sounds like they're migrating back to my 1997 apple newton's memory design. hmm.

m.

[entropy1980]

If it's implemented in such a way that pressing the power button puts it into suspend and pressing and holding the power button turns the device off, I think this is a moot point. It won't be as big of a hurdle as you think it will be. ;-)

I don't think it's a big deal, i just did when I thought you said when off (I read: suspended :) ) alarms wouldn't work. Then that would be a big deal. But if they work as they are supposed to work now ( :wink: ) then it's a non-issue.

[cmorris]

64 MB of pure application execution space will go a lot further than the 25 MB or so that most of us have after a soft reset. Sweet!

Is it true though that you'll actually have 64MB of "pure application execution space"? Won't the OS still need to use some RAM when it is running?

I would expect a freshly booted WM 5.0 device with 64MB RAM to have somewhere between 25 and 64 MB free - maybe something closer to 40?

[lorettaboy]

128 MB ROM and 64 MB RAM is a logical storage arrangement under the new memory management scheme, but the point many of us have been raising for a long time is that it is still insufficient for power users. Movies, map data, large web pages, complex documents, sophisticated games... all are memory hogs and can very easily exceed 64 MB, even with intelligent garbage collection. High end devices should still have at least 128 MB of RAM for these applications. 128 MB of RAM under WM5 will be more memory than 128 MB of RAM under earlier releases, but I consider that to be a much-needed bug fix. :twisted:

This is exactly why i love my hx2750!

[Jason Dunn]

Movies, map data, large web pages, complex documents, sophisticated games... all are memory hogs and can very easily exceed 64 MB, even with intelligent garbage collection.

Ok, I need you to show me some hard data here - what type of Web page would require 64 MB of execution space? Or even more than 2 MB? Remember the STORAGE of the images/text on a Web page will be in Flash ROM. VGA resolution videos take about 10 MB of RAM to play in WMP 10 Mobile. Most complex games I've seen take between 8 and 15 MB, and those are the BIG ones. I don't say this lightly, but I think you're spreading FUD - I can't see how even a power user could use up 64 MB of execution RAM...

[Fred44]

Jason Dunn your concept of Persistent Storage is not correct. Persistent Storage is storage that executes in place out of Flash. Read this link

http://www.intel.com/design/flcomp/toolbrfs/298073.htm

Quote “Unlike other data (FLASH) only storage solutions, the code can be direct executed (XIP), demand paged, or memory mapped.”

That is the reason high end PDA went from 128MB to 64MB of SDRAM and 64MB to 128MB+ of FLASH.

Pocket PC currently uses a memory manager that balances Storage and Program in SDRAM. The additional FLASH that is not used for boot code is mapped to a non volatile FLASH drive. That extra FLASH drive can be as small as 64MB.

I think it would be great if Pocket PC worked like a PC. Use a small FLASH (64MB) device to boot the OS. Offer 256MB of SDRAM for executing code and use a removable SD (2GB) card for storage.

[johncruise]

I have the same concerns as entropy1980. I don't like the idea of having a PDA that I will turn off and then I won't be seeing anymore alarms/notification messages anymore (as if it's really fully working already). If MS is concern how OEM is having problems with battery life, they better think again cause this is not the best way to go. Anyway, that would be the end of my PPC/WM purchase if MS insist on that idea. I rely heavily on this feature.

[Stephen Beesley]

gee, sounds like they're migrating back to my 1997 apple newton's memory design. hmm.

m.

... and about time IMHO!

The sig says it all...

[Jason Dunn]

Is it true though that you'll actually have 64MB of "pure application execution space"? Won't the OS still need to use some RAM when it is running? I would expect a freshly booted WM 5.0 device with 64MB RAM to have somewhere between 25 and 64 MB free - maybe something closer to 40?

A good point. I don't have an answer to that - if the core OS will gobble up 25 MB of that RAM, then yeah, we might have a problem. My understanding was that the majority of that 64 MB will be available for program execution. My X50v is using 9.30 MB of program memory after a soft reset, leaving me 55 MB to execute applications. Seems like plenty to me, even if I run a big game, watch a movie, etc. This will be worse on a phone edition device, they tend to need more execution RAM for the phone bits.

If Pocket Internet Explorer still lacks a way to limit the cache size we may run out of Flash ROM space, but that's another problem entirely. ;-)

I guess we'll have to wait and see...

[D.psi]

My one concern, would be an eventual pig-out on dynamic memory usage... (Anyone remember the "No one would ever need more than 640KB of memory space days?"). Yes presently 64 MB of RAM is plenty, but given time and entropy, we will soon find that apps won't comfortably run in that space either.

[mr_Ray]

While not wanting to sound like too much of a wet blanket, I never got the "64MB RAM sucks now but it'll be cool once Magneto gets here" point of view. I'm sure that many here have a PocketPC lifetime of 1-1.5 years. So after having that fancy new VGA PocketPC for nearly a year by the time Magneto actually hits the shelves, you've went a year with a less than optimal RAM/ROM configuration, and when the upgrade arrives that eases the situation you're already eyeing up the new models anyway...

About the "everything in ROM so you can really turn it off" proposal - while that would be really neat, you'd have to have literally everything short of temp files in ROM to make it workable, and with Flash ROM being so much slower it could bring on some serious performance issues... still that's been discussed to death elsewhere.

Also what would that mean for the hard reset? What happens if something goes wrong in Windows\Startup? Will a hard reset not wipe the ROM storage, in which case you'll have a problem you can't fix, or is ROM storage suddenly not safe from hard resets? Potential bummer either way, really.

Sorry for the negativity, but i'm an inherently cynical guy. :wink:

[Jason Dunn]

I have the same concerns as entropy1980. I don't like the idea of having a PDA that I will turn off and then I won't be seeing anymore alarms/notification messages anymore (as if it's really fully working already).

Would you expect your Pocket PC to sound alarms if you pulled out the battery? Would you expect your car radio to work if you turned off the car and pulled out the key? Would you expect your PC to check for email messages if you turned it off? This is absolutely no different.

How have I failed to explain this? 8O

[Jason Dunn]

Jason Dunn your concept of Persistent Storage is not correct. Persistent Storage is storage that executes in place out of Flash...

That's the way Pocket PCs work today. When I run Contacts, it copies the 1 MB executable over to RAM and runs it, using up 1 MB of program RAM (I'm using theoretical number here). That will not change in Magneto. What WILL change however are the many MB of storage that the OS, and third party applications fill up RAM with. Internet Explorer temporary files, Today screen plug-ins, etc. All of that will be moved into Flash ROM, which will help out a lot!

I think it would be great if Pocket PC worked like a PC. Use a small FLASH (64MB) device to boot the OS. Offer 256MB of SDRAM for executing code and use a removable SD (2GB) card for storage.

You're suggesting that data files and programs, basically anything outside the core OS, be put in a removable device? Do you have any concept of how unstable and potentially dangerous for data integrity that would be? It would be a complete disaster. One accidental un-mounting of that storage card and the device would crumble.

Microsoft's Windows Mobile 5 model is the best options because it works like a PC. RAM is RAM, used for program execution. Flash ROM is the hard drive where everything is permanent. If you pull the power plug on your PC, you lose what's in RAM, but all your data is still safe on the hard drive. This is no different.

People who have used Windows Mobile Smartphones will grasp how useful this design is, because it's what we've already been using for years...

[JonnoB]

If the MPx had a little more flash rom for programs and the OS, the 12mb of usable RAM would be closer to the original 32 and this might have made it more usable.

[Jason Dunn]

My one concern, would be an eventual pig-out on dynamic memory usage... (Anyone remember the "No one would ever need more than 640KB of memory space days?"). Yes presently 64 MB of RAM is plenty, but given time and entropy, we will soon find that apps won't comfortably run in that space either.

The difference is that the infamous quote was based around a limitation of the OPERATING SYSTEM. Windows CE can address much more than 64 MB of RAM. The reason why we don't have 256 MB devices is cost and battery life. The more RAM you put into a Pocket PC, the more it will cost and the worse the battery life will be. You can be sure that you'll see Windows Mobile 5 Pocket PC with 128 and more of RAM. My only point in making the original post was that devices with 64 MB of RAM will have more breathing room and function better on Windows Mobile 5 than with the old OS.

[Jason Lee]

While not wanting to sound like too much of a wet blanket, I never got the "64MB RAM sucks now but it'll be cool once Magneto gets here" point of view. I'm sure that many here have a PocketPC lifetime of 1-1.5 years. So after having that fancy new VGA PocketPC for nearly a year by the time Magneto actually hits the shelves, you've went a year with a less than optimal RAM/ROM configuration, and when the upgrade arrives that eases the situation you're already eyeing up the new models anyway...

About the "everything in ROM so you can really turn it off" proposal - while that would be really neat, you'd have to have literally everything short of temp files in ROM to make it workable, and with Flash ROM being so much slower it could bring on some serious performance issues... still that's been discussed to death elsewhere.

Also what would that mean for the hard reset? What happens if something goes wrong in Windows\Startup? Will a hard reset not wipe the ROM storage, in which case you'll have a problem you can't fix, or is ROM storage suddenly not safe from hard resets? Potential bummer either way, really.

Sorry for the negativity, but i'm an inherently cynical guy. :wink:

from the way i understand it a hard reset will be very easy. you will simply take out the cd and reflash the rom. just like when you update your rom now. a little utilityu to flash your rom back to factory. same as a hard reset now.

[Jason Dunn]

About the "everything in ROM so you can really turn it off" proposal - while that would be really neat, you'd have to have literally everything short of temp files in ROM to make it workable, and with Flash ROM being so much slower it could bring on some serious performance issues... still that's been discussed to death elsewhere.

Have you ever used a Smartphone? That's the way they work: when you press and hold the power button and actually turn the phone off, it takes a few seconds to write things to the Flash ROM. It's really not a big deal. And remember, it's not like when you press the power button the Pocket PC will be turned off. That's suspend. A true off mode where it's "dead" will be something most people will not use very often.

Also what would that mean for the hard reset? What happens if something goes wrong in Windows\Startup? Will a hard reset not wipe the ROM storage, in which case you'll have a problem you can't fix, or is ROM storage suddenly not safe from hard resets? Potential bummer either way, really.

Again, this is already done and functional in the Smartphone world. There's an easy way to reset the phone back to factory specs - the phone knows what is "original ROM data" versus "user ROM data" so hard resetting it isn't a problem.

[PPCRules]

My understanding is that besides the significantly slower speed, flash memory has a significantly shorter re-write life span than RAM does. I'm wondering if constantly rewriting OS temp files to flash will exceed the memory cell life span at some point. I can't run the numbers, and I suppose if it's 25 years of heavy use, it's not a problem. But I'm sure the life span is a lot less than harddrives, which we are comparing to here.

[johncruise]

Would you expect your Pocket PC to sound alarms if you pulled out the battery? Would you expect your car radio to work if you turned off the car and pulled out the key? Would you expect your PC to check for email messages if you turned it off? This is absolutely no different.

How have I failed to explain this? 8O

:? You are missing the point Jason. What I am saying is "I don't like for MS to go through this route". I don't know about you but a number of people bought a Pocket PC with the expectations that this features will work for them (alarm is one of them). What is the use of a reminder in a Calendar item if alarms don't work?

What you explained is a no brainer. Everybody understand that completely.

[mr_Ray]

About the "everything in ROM so you can really turn it off" proposal - while that would be really neat, you'd have to have literally everything short of temp files in ROM to make it workable, and with Flash ROM being so much slower it could bring on some serious performance issues... still that's been discussed to death elsewhere.

Have you ever used a Smartphone? That's the way they work: when you press and hold the power button and actually turn the phone off, it takes a few seconds to write things to the Flash ROM. It's really not a big deal. And remember, it's not like when you press the power button the Pocket PC will be turned off. That's suspend. A true off mode where it's "dead" will be something most people will not use very often.

Also what would that mean for the hard reset? What happens if something goes wrong in Windows\Startup? Will a hard reset not wipe the ROM storage, in which case you'll have a problem you can't fix, or is ROM storage suddenly not safe from hard resets? Potential bummer either way, really.

Again, this is already done and functional in the Smartphone world. There's an easy way to reset the phone back to factory specs - the phone knows what is "original ROM data" versus "user ROM data" so hard resetting it isn't a problem.
True I suppose. :)
I guess that debating it either way is pointless, we'll just see what happens when we have real software running on real silicon. :)

[WyattEarp]

My question is when will we get devices with a user-accessible 128MB FlashROM. Current configurations still only give us 80 to 90MB FlashROM which is still insufficient and misleading as far as I am I'm concerned. I know I need at least 128 MB of user-accessible FlashROM for me to move to a new PPC.

As far as RAM goes 64 might be enough to run everything but some how I think this will get messed up and not work. OEMs will find someway to give us less with some lame excuse behind it.

[applejosh]

Would you expect your Pocket PC to sound alarms if you pulled out the battery? Would you expect your car radio to work if you turned off the car and pulled out the key? Would you expect your PC to check for email messages if you turned it off? This is absolutely no different.

How have I failed to explain this? 8O

:? You are missing the point Jason. What I am saying is "I don't like for MS to go through this route". I don't know about you but a number of people bought a Pocket PC with the expectations that this features will work for them (alarm is one of them). What is the use of a reminder in a Calendar item if alarms don't work?

What you explained is a no brainer. Everybody understand that completely.

And for the vast majority of people they will go into suspend mode (which will look like off like it does now), in which case, alarms will work. "Off" in this connotation is only if you manually do a complete shutdown (akin to shutting down your PC completely). I believe this has been explained to death in the thread. When you "turn off" your PPC now, you're not really turning it off. You're putting it into suspend mode. Off in the sense that Jason explained it is if you were to remove your battery from your current PPC and throw it in a drawer.

I don't know if I still like the idea since writing stuff to flash is notably slower than "writing" to RAM. Look at the T5 as an example. The T3 was a speed demon. Then PalmOne decided to have stuff kept in non-volatile space and the T5 was born. My T5 is a helluva lot slower than my T3 because it has to save stuff back to the flash. (I do believe that WM 5.0 will be better than this, but I still think it will be slower.)

[Fred44]

That's the way Pocket PCs work today. When I run Contacts, it copies the 1 MB executable over to RAM and runs it, using up 1 MB of program RAM (I'm using theoretical number here).
Persistent Storage means execute in place.

Moving an executable from FLASH to RAM is not execute in place. Leaving an app in Flash and running (executing) it out of FLASH (place) is.

This link describes what Persistent Storage means.

http://www.intel.com/design/flcomp/toolbrfs/298073.htm

You're suggesting that data files and programs, basically anything outside the core OS, be put in a removable device? Do you have any concept of how unstable and potentially dangerous for data integrity that would be?
The PC has been doing that for years with a lot of success. A FLASH drive is a lot more reliable the a rotating HD used in a PC.

[Jason Dunn]

What I am saying is "I don't like for MS to go through this route". I don't know about you but a number of people bought a Pocket PC with the expectations that this features will work for them (alarm is one of them). What is the use of a reminder in a Calendar item if alarms don't work?

Microsoft is not taking any features away, they're adding a new feature that will allow you, if you want, to put your device in a mode whereby you can leave it in your desk for a few months and have it wake up and work like the day you put it in there. If you never use this feature nothing will change for you from how things work today. This is something that Smartphones can to today.

When you see it in action for yourself, you'll smack your forehead and shout "DUH!" as it all becomes obvious. ;-)

[johncruise]

"Off" in this connotation is only if you manually do a complete shutdown (akin to shutting down your PC completely). I believe this has been explained to death in the thread. When you "turn off" your PPC now, you're not really turning it off. You're putting it into suspend mode. Off in the sense that Jason explained it is if you were to remove your battery from your current PPC and throw it in a drawer.

*sigh* how many times do I need to explain that I understand what people are saying about "making the unit _completely_ off on the next round of release" and "we currently have _suspend_ mode as opposed to _total_ off mode".

my point is... (read my previous reply)

[johncruise]

they're adding a new feature that ....

Ahhhh.... now it's more clear. I could have sworn I read otherwise. :oops:

[applejosh]

Persistent Storage means execute in place.


Persistent storage means that if I take power away from the device, things won't be erased. And the only place I've seen execute in place is on a PalmOS device (where programs that are run from RAM don't take up considerably more RAM when run). I don't know of a PPC app that uses XIP tech now. Apps are copied from the Storage RAM partition to the program memory when they are run. Not that I wouldn't like it to be XIP, but my understanding is that this doesn't exist in today's PPC devices.

[lapchinj]

... Sweet! :D
Yeah :mrgreen:
I understand that this all on paper but is there been a timeframe connected with all this before anything starts showing up?

Jeff-

[alex_kac]

Would you expect your Pocket PC to sound alarms if you pulled out the battery? Would you expect your car radio to work if you turned off the car and pulled out the key? Would you expect your PC to check for email messages if you turned it off? This is absolutely no different.

How have I failed to explain this? 8O

:? You are missing the point Jason. What I am saying is "I don't like for MS to go through this route". I don't know about you but a number of people bought a Pocket PC with the expectations that this features will work for them (alarm is one of them). What is the use of a reminder in a Calendar item if alarms don't work?

What you explained is a no brainer. Everybody understand that completely.

Why do you not like this? Its just an added option to turn off the device completely. Its not any different operation. I have a WM5 device and I cannot for the life of me figure out how to put it in "Off" mode besides taking the battery out. But the nice thing is if I put the battery back in - all my data is still on the device.

[alex_kac]

That's the way Pocket PCs work today. When I run Contacts, it copies the 1 MB executable over to RAM and runs it, using up 1 MB of program RAM (I'm using theoretical number here).
Persistent Storage means execute in place.

Moving an executable from FLASH to RAM is not execute in place. Leaving an app in Flash and running (executing) it out of FLASH (place) is.

This link describes what Persistent Storage means.

http://www.intel.com/design/flcomp/toolbrfs/298073.htm

You're suggesting that data files and programs, basically anything outside the core OS, be put in a removable device? Do you have any concept of how unstable and potentially dangerous for data integrity that would be?
The PC has been doing that for years with a lot of success. A FLASH drive is a lot more reliable the a rotating HD used in a PC.

Whatever Intel calls Persistent Storage means nothing in this context. Microsoft is calling it Persistent Storage because to the user - that's what it is. Take all power from the device and the data is still there.

[surur]

I think you underestimate how much memory web pages use. On my desktop, with 6 tabs open, Maxthon uses 40Mb of real memory and 70Mb of virtual memory. On the PPC I use netfront. The program itself uses 1311 Kb (without java installed).

PPC mobile front page = 786 Kb
slasdot frontpage = 836 Kb
Fark front page = 3140 Kb
One fark thread = 3672Kb
Website of my cinema =1200Kb

I also had a number other programs open, including eReader, which came in at 550Kb.

Surur

[Jason Dunn]

The PC has been doing that for years with a lot of success. A FLASH drive is a lot more reliable the a rotating HD used in a PC.

Show me a PC that stores vital program databases on an SD card that's accessible from a slot where the user can yank it out while the device is running please. There isn't one, because that would be an insane design. You're effectively saying that we should put the Windows XP registry on a CompactFlash card and trust users not to yank it out at the wrong moment, or somehow have an operating system that could cope with critical data being missing. In your model the contacts database, email database, calendar database, and tasks database would all be on a Flash card.

I understand what you're saying about the reliability of Flash versus hard drives, and I agree, but given the way Pocket PCs designed with external Flash card slots, what you're suggesting is simply foolish.

Thankfully, this is a decision that was in Microsoft's hands and not yours. ;-)

[crashdau]

Having approx 64mb of ram for execution will be the bomb! I, for one, can't wait! Is there any approximation on size of ROM memory used for the os and all the other apps that come with will take up?

On my HX4705 with 80mb of rom, I'm hoping that it will still leave room to install my 3rd party apps to it leaving that 64mb for execution.

[TheWolfen]

I'm not so sure about this new approach to memory. As I see it now, I can choose to install apps in one of 3 places.. RAM (128MB and fast - w/ my upgraded X50v), ROM (128MB - slower) or storage card (fast w/ a good card). How is eliminating one of those options a good thing? Sure, apps will have more RAM available to them, but they will run slower due to the slower flash memory speeds, correct? And while right now I can fill up my ROM and most of my RAM with installed apps (if I choose to), with 5.0 I lose 128MB of potential storage.

I can see where this is more logical, and will definitely help out those with 64MB RAM devices, but it hurts me, near as I can tell. Am I wrong here?

[djdj]

I'm really looking forward to the new Windows Mobile 5 devices!
Would I be making a huge mistake if I were to buy an HP hx4705 now as opposed to waiting for something better down the road?

I currently have an HP 5550 and am using all 128MB of its memory, which has kept me from getting a newer iPAQ. The whole persistent storage thing is intriguing, and perhaps I could "fit" on an hx4705, but I don't want to buy something that might be replaced any time in in the near future.

[gibson042]

Movies, map data, large web pages, complex documents, sophisticated games... all are memory hogs and can very easily exceed 64 MB, even with intelligent garbage collection.

Ok, I need you to show me some hard data here - what type of Web page would require 64 MB of execution space? Or even more than 2 MB? Remember the STORAGE of the images/text on a Web page will be in Flash ROM. VGA resolution videos take about 10 MB of RAM to play in WMP 10 Mobile. Most complex games I've seen take between 8 and 15 MB, and those are the BIG ones. I don't say this lightly, but I think you're spreading FUD - I can't see how even a power user could use up 64 MB of execution RAM...
Please forgive the wording of my original post. In the general case, I meant to refer to the RAM used in a multitasking context as opposed to a single application. I don't have much hard data, and I don't have any on the memory footprint of WM5, but I will make what I consider to be a reasonable guess and assume that the OS will consume about 20 MB while running (we're talking hardcore users here, so this is a unit with an embedded phone and all three radios active). On a device with 64 MB of RAM, this leaves 45 MB free for applications.

I am only aware of one class of applications that could consume this much on their own: navigation software. Call it bad form if you like, but many of them operate by loading entire maps into memory. To pick one example from a list of literally dozens:

when I run copilot live (gps software) I have found that I better leave everything else off. I've got 64 megs now and I store everything possible in a cf card. It would be nice to have most of the apps in the machine.
Second in memory usage probably goes productivity software. TextMaker and PlanMaker are very powerful, and are also well known for their RAM consumption when working with large files. 10-15 MB is not out of the question.

WMP takes up about 10 MB while showing VGA video at 30 fps, and let's say 3 MB for high quality audio. Large games (Atlantis Redux, for example :wink:) use up to 20 MB. And PIE uses about 2 MB, per page with MultiIE or PIEPlus or the like, not including cache. Not only that, but a single page viewed in PIE with no other applications running on WM2003SE is enough to take down an X50v with 64 MB of RAM (http://www.pocketpcthoughts.com/forums/viewtopic.php?t=35228).

Given these figures, it is not at all difficult to come up with situations that stress or exceed the limitations of 64 MB. A user could have 5 web pages open with Pocket Plus, a big spreadsheets in PlanMaker and a corresponding report in TextMaker, and Spb Finance or a video in WMP for double-checking facts/data. They could be running navigation software, separate trip logging software, and WMP for music. They could get an SMS or phone call while playing a game. They could just be viewing a page with lots of images.

There are many examples on this site of people struggling under the current system with 64 MB of RAM, to the point of having to abandon multitasking and even having to soft reset before using a program. Assuming that the switch of storage space from RAM to ROM frees up about 20 MB of RAM, that gives us back multitasking... but only partially in some cases, and just barely in the best cases. Even though 64 MB of execution RAM will be enough for most people (myself included, actually), a true power user will definitely be able to use more, and so the high end devices should still offer 128 MB.

It's not that 64 MB isn't enough for me, it's that there are enough not-too-uncommon situations for someone to legitimately demand more. Current 128 MB models already leave more than 64 MB available for execution.

[alex_kac]

On a soft reset WM5 Phone Edition device with phone function on - WM5 takes up 13.02 MB of RAM. So a 64 MB device would be left with about 51MB for running apps.

[alex_kac]

I'm not so sure about this new approach to memory. As I see it now, I can choose to install apps in one of 3 places.. RAM (128MB and fast - w/ my upgraded X50v), ROM (128MB - slower) or storage card (fast w/ a good card). How is eliminating one of those options a good thing? Sure, apps will have more RAM available to them, but they will run slower due to the slower flash memory speeds, correct? And while right now I can fill up my ROM and most of my RAM with installed apps (if I choose to), with 5.0 I lose 128MB of potential storage.

I can see where this is more logical, and will definitely help out those with 64MB RAM devices, but it hurts me, near as I can tell. Am I wrong here?

It helps you because:

1) if you have 128MB of RAM right now, half of it is being used no matter what for "storage". So with 128MB of RAM on your device you are current available program RAM is 64MB and nothing you do is going to help you get more. Not only that but if you fill up your PIM databases, or use any app that uses the CE database system, all those are going to go directly in your memory eating away at the amount of RAM you have available for running apps.

2) Under WM2003 - anytime you run out of battery, you will lose everything in memory. All data, settings, and apps.

3) Under WM5, you have 128MB RAM period. Take away about 13-15MB for running the OS and you'll end up with 110 or so for running applications. You can keep filling up your PIM databases or notes or registry, etc... without hurting your available application RAM.

So even at the VERY least, what you gain is the persistence of your data even if you accidentally drain your battery. But you also do gain in having more memory allocated to apps and a more defined space for data.

[jngold_me]

I am only aware of one class of applications that could consume this much on their own: navigation software. Call it bad form if you like, but many of them operate by loading entire maps into memory. To pick one example from a list of literally dozens...

I don't know where to begin. I will say this: My older 4150 was able to run every single app category you mentioned above even in multi-tasking mode with just as much memory as a current 4700 (and even less considering that the 4150 had a paltry amount of FS memory). I was running WA2, Weather Panel, Pocket breeze, and apps such as MultiIE, and other so-called memory hogs. Granted when running GPS apps such as PocketMap Navigator and Destinator3 I would perform a soft reset to clear memory. However, my 4150 at any given time had about 12-16mb dedicated to program memory which was fine for multimedia, internet access and such.

Of course, all bets are off if indeed the memory requirement for VGA-specific apps (which not sure how many are vga-specific) are exceedingly more than a non-vga device.

Well, anyways, now that I have a 2750 I am in no way complaining with the extra space that the device offers.

***Excessive quote snipped by moderator JD***

[alex_kac]

Remember that VGA apps always will use up more RAM just by the fact that their images are going to be larger and the screen buffer will be too.

[disconnected]

Someone mentioned the scenario of having something go badly wrong, and a hard reset not fixing it because the problem was caused by something in persistent storage. Would you really have to reflash the ROM (not possible if you're away from a PC), or will backup/restore utilities somewhow be able to handle this?

[dlangton]

Is ROM really so trustworthy as a storage medium? I'm seeing too many reports of people losing their ROM storage for me to consider it as reliable as a CF/SD card. Not that I don't see way too many problems with SD cards :(

[Darius Wey]

Yeah :mrgreen:
I understand that this all on paper but is there been a timeframe connected with all this before anything starts showing up?

You can probably expect new WM5 devices to poke their head in the market sometime around late Q3/Q4. For now, you can expect the X50s and hx2000/hx4700 to sport the new interface first (once the upgrade is made available).

[alex_kac]

At least on the device I have, its a few simple steps to reset the FlashROM to factory defaults. As for its reliability considering its the same ROM that holds the OS, its going to be as or more reliable than storage cards. Sure some will be bad, but I personally have had 3 CF cards go bad on me too.

[jngold_me]

Is ROM really so trustworthy as a storage medium? I'm seeing too many reports of people losing their ROM storage for me to consider it as reliable as a CF/SD card. Not that I don't see way too many problems with SD cards :(

Real good question! In the past, I have fallen victim to the dreaded "disappearing filestore" on a Jornada 560 series. It required me having to send the device back to HP for replacement. What's scary, as you mention, people are still experiencing the same issues on current devices. From what I have seen, it looks like when the FS hits some mystical capacity, it decides to just disappear.

Makes one wonder....

[Darius Wey]

I'm not so sure about this new approach to memory. As I see it now, I can choose to install apps in one of 3 places.. RAM (128MB and fast - w/ my upgraded X50v), ROM (128MB - slower) or storage card (fast w/ a good card). How is eliminating one of those options a good thing? Sure, apps will have more RAM available to them, but they will run slower due to the slower flash memory speeds, correct? And while right now I can fill up my ROM and most of my RAM with installed apps (if I choose to), with 5.0 I lose 128MB of potential storage. I can see where this is more logical, and will definitely help out those with 64MB RAM devices, but it hurts me, near as I can tell. Am I wrong here?

128MB RAM is great, but it's not entirely essential when you have a large amount of ROM and storage card memory as well. For now, and considering WM5, 64MB RAM should be sufficient, but I'm sure a year or two down the track, once requirements increase, 128MB may be the norm. I'm surprised a lot of people are raising an eyebrow at WM5's new memory management system though. I support it, and when you look at all the current memory problems we have now, you'll know why. Having shared program and storage memory in RAM is hardly efficient because (1) you have less allocated for each purpose, and (2) with a lesser amount, you can have potential problems once the memory demands exceed the supply. With WM5 now in, you can expect less problems now that you have an extra reserve capacity left over for data execution. ROM is only slightly slower than RAM, and it's hardly something to burst a bubble over. Overall, processes executed in Windows Mobile should be as fast as usual, unless you want to get all technical and start factoring in millisecond discrepancies.

[dlangton]

I know for certain that one way to kill Flash ROM is to attempt to write more than its capacity. I certainly would hope that WM 2005 takes that little problem into consideration.

[alex_kac]

As for ROM speed, the newer devices like the 4700 and the Dell x50 have a very fast ROM read speed. Write is still slow, but reading chunks of data is pretty fast. Some apps that may read/write data in very small chunks may have to be updated to read/write in larger chunks, but if they do you will not see that much difference.

[Ed Hansberry]

Waitaminute... what's this about my alarms not working when I turn it off?!?

;-) :lol:

[alex_kac]

I know for certain that one way to kill Flash ROM is to attempt to write more than its capacity. I certainly would hope that WM 2005 takes that little problem into consideration.

Do you have a sample method I could try and see if I can replicate this? I KNOW this could occur in some devices pre-WM5, but I believe that in WM5 many issues with FlashROM are gone since the entire design is based on it.

[fmcpherson]

Do we know for sure whether upgraded devices (the HPs and Dells) will implement persistent storage? I would think yes since it sounds like that will be the way WM5 works, but I am wondering whether Jason or anyone else knows for sure?

[alex_kac]

Yes, it is a requirement of WM5, at least from what MS has told us developers.

[Darius Wey]

Do we know for sure whether upgraded devices (the HPs and Dells) will implement persistent storage? I would think yes since it sounds like that will be the way WM5 works, but I am wondering whether Jason or anyone else knows for sure?

As far as I'm aware, the operating mechanism behind WM5 will not change based on device-specificity. It's a universal thing that will be adopted by all upgradeable WM5 devices and new WM5 devices.

[Dalantech]

Persistent Storage means execute in place.

Yes, but it also means "run dirt slow" since RAM is a couple of orders of magnitude faster than ROM. Just because something can be done doesn't mean that it should be done...

[huangzhinong]

Persistent Storage means execute in place.

Yes, but it also means "run dirt slow" since RAM is a couple of orders of magnitude faster than ROM. Just because something can be done doesn't mean that it should be done...

True. The more I think about WM5 memory managerment, the more I believe third parties apps will be slower than in previous OS. Some apps may be very slow, such as styletap, which is almost useless if installed into storage card or ROM.

[WillyG]

Waitaminute... what's this about my alarms not working when I turn it off?!?

;-) :lol:

I believe its a new feature. But the information about this must have leaked, i could swear i heard about it for the first time 5 years ago. :wink:

[Fred44]

Persistent Storage means execute in place.
Yes, but it also means "run dirt slow" since RAM is a couple of orders of magnitude faster than ROM. Just because something can be done doesn't mean that it should be done...
You can read from a FLASH device at 45ns, SDRAM used in PPC is either 66MHz (15ns) or 100MHz (10ns). Both are very fast. HD’s used in the fastest PC’s today have a initial access of 10ms (10,000ns). Why do you think FLASH is "run dirt slow"?

[Dalantech]

I do have on question: Will I be able to load applications on CF and SD, or do all applications have to fit on the ROM that's built into the device?

[Jonathon Watkins]

Yes, but it also means "run dirt slow" since RAM is a couple of orders of magnitude faster than ROM. Just because something can be done doesn't mean that it should be done...

Ummm, no. Flash may be a few tens of percent slower than DRAM, but it's not orders of magnitude. It should not be a huge performance hit.

[Dalantech]

You can read from a FLASH device at 45ns, SDRAM used in PPC is either 66MHz (15ns) or 100MHz (10ns). Both are very fast. HD’s used in the fastest PC’s today have a initial access of 10ms (10,000ns). Why do you think FLASH is "run dirt slow"?

The difference doesn't sound like much, until you stop to think about having to write several hundred (or thousand) bytes of data and then the difference starts to add up fast. For example: If I load Legacy (an RPG) into RAM and then play for a while and save the game the save writes in a tenth of a second. Load the same game onto a high speed SD card and the game takes a second or more to write the same file.

[Dalantech]

Ummm, no. Flash may be a few tens of percent slower than DRAM, but it's not orders of magnitude. It should not be a huge performance hit.

True, I exaggerated. It will none the less be a noticeable difference in performance when you take into account the amount of data that has to be read or written. As an experiment try loading an application in RAM, file store, and then a SD or CF card and see how the program performs on all of them. If you don't notice a difference then you've got a very slow PPC...

[brucejackson]

Hi,

I certainly "know" that access to data on my external storage card is a factor of 5-10 times slower (from performance tests for our DB app)- however this is probably due to the interface. If the flash memory is internal and not limited by bus restrictions? hopefully we wont take such a hit.

Bruce

[Dalantech]

Hey Bruce,
Some SD and CF cards have really slow write times -they all seem to read pretty fast but writing is what separates the low end cards from the "Extreme" variety...

[alex_kac]

Let me see if I can inject some of what I know about this here.

First - FlashROM IS slower than real RAM. Its latency is higher. But its actual transfer of data is not, or not that much slower - depending on the hardware. Apps written for WM5 need to take into account their read/write processes. If you sit and read a byte in a loop, its going to be VERY slow. If you read 1KB of data at a time or better yet - 4-8KB in one fell swoop, you will barely notice a difference. If you use the internal databases - they are already designed for this and you may even see a speedup since the internal databases now use EDB which is faster than CEDB was.

The next issue is the hardware. It is no coincidence that some of the latest devices like the iPaq 4700 and the Dell x50 have much faster FlashROM than previous devices.

So an app that does not take into account its new environment may be a lot slower. An app that is written to buffer and read large chunks of data will see either a speed increase or nothing at all.

Application loading IS a bit slower, but that's just like on the desktop where the first time you run IE or Word or whatever, it takes a bit longer. Once the DLLs are in memory, everything launches a bit faster.

I can't give you actual times because the device I'm developing against is an older device with a very slow FlashROM. But even on such a device running at 400Mhz, I actually see some speed gains in a few areas from my 4700, though app loading is noticeably slower.

[alex_kac]

I do have on question: Will I be able to load applications on CF and SD, or do all applications have to fit on the ROM that's built into the device?

Not only can you, but the installer on the Pocket PC itself now asks you if you want to install it on Storage or main memory.

[Darius Wey]

Is there any approximation on size of ROM memory used for the os and all the other apps that come with will take up?

The base WM5 footprint is ~18-19MB.

[alex_kac]

I hadn't checked on the actual ROM size - but wow, its smaller than WM2003SE? I know 2003SE was about 24-26MB for the Pro version, and 14 or so for the non-Pro version.

[Darius Wey]

I hadn't checked on the actual ROM size - but wow, its smaller than WM2003SE? I know 2003SE was about 24-26MB for the Pro version, and 14 or so for the non-Pro version.

I don't think I've got that figure wrong. If I recall correctly, ~18-19MB was an absolute base WM5 footprint estimation. However, I haven't got much sleep in the past day, so if I've made a mistake, attribute it to that. :lol:

[crashdau]

The base WM5 footprint is ~18-19MB.

Wow, that is smaller then WM2k3. I guesstimating that WM2k3 is approx 48mb, since I have 80mb user accessible.

Will the Windows folder migrate with the ROM?

[Darius Wey]

Wow, that is smaller then WM2k3. I guesstimating that WM2k3 is approx 48mb, since I have 80mb user accessible.

Remember it's only a base figure. Once vendors customise it for device specificity, the space consumed will most likely rise.

Will the Windows folder migrate with the ROM?

It will all be in the ROM.

[jickbahtech]

Hey,
Got to this thread late I guess...
I'm still not really getting why people are this concerned about the changes to RAM/ROM allocation. On my PC at home I have 1GB of RAM. 128MB of this is a RAM Drive where I keep a couple programs that I like to run quickly. If people are concerned about not using RAM for storage on a PPC, shouldn't we look into this solution as well.

I'm kinda excited to see my 2750's RAM be just that. I'm barely using any of the ROM (only mission critical apps), and most everything else will be storage card. For users of the VGA PPC's, just imagine what kind of hi-res apps the device will be capable of soon. Current software is based on current hardware, and with 64MB of RAM (or 128 for you warranty void-ers out there) I think we're about to see what this platform is really capable of.

As long as MS and OEMs don't botch it...

[PBR]

Persistent Storage means execute in place.

Yes, but it also means "run dirt slow" since RAM is a couple of orders of magnitude faster than ROM. Just because something can be done doesn't mean that it should be done...

True. The more I think about WM5 memory managerment, the more I believe third parties apps will be slower than in previous OS. Some apps may be very slow, such as styletap, which is almost useless if installed into storage card or ROM.

I have Styletap and all its apps installed on my SD card and it runs just fine on my X50V

[huangzhinong]

Persistent Storage means execute in place.

Yes, but it also means "run dirt slow" since RAM is a couple of orders of magnitude faster than ROM. Just because something can be done doesn't mean that it should be done...

True. The more I think about WM5 memory managerment, the more I believe third parties apps will be slower than in previous OS. Some apps may be very slow, such as styletap, which is almost useless if installed into storage card or ROM.

I have Styletap and all its apps installed on my SD card and it runs just fine on my X50V

Running styletap from sd card is not problem. The speed is the problem. You can move them to RAM and compare the speed.

[alex_kac]

All that shows is that Styletap needs to be updated to run well. It might be as simple as loading everything it needs into RAM as a simple solution (though not ideal).

[Menneisyys]

About the "everything in ROM so you can really turn it off" proposal - while that would be really neat, you'd have to have literally everything short of temp files in ROM to make it workable, and with Flash ROM being so much slower it could bring on some serious performance issues... still that's been discussed to death elsewhere.

With the current crop of even high-end devices (I speak of devices like the hx4700 and the Pocket Loox 720), I don't see it feasible to come up with a browser that stores its cached stuff into the Persistent Storage to work at least reasonably fast. (Future devices with greatly enhanced File Store writing/file creation speeds will definitely be better in this respect.)

I've done quite much of speed benchmarking and found out (http://www.pocketpcthoughts.com/forums/viewtopic.php?t=36376) that putting the Pocket Internet Explorer (PIE) cache in current VGA devices' File Store can cause a performance degradation of an order of magnitude. If PIE's caching model is made better in the new op. system version, "old", "legacy" programs like Netfront will still have big problems when run from the File Store because of the cache.

If, on the other hand, the cache will be configurable to be put even in RAM, everything will be OK.

The same stands for some other "legacy" apps too - for example, SimpleSMS. It's just intolerably slow run from the File Store because it does a lot of file creation/write behind the scenes.

Bottom line: with current (hyperslow) File Stores there will be problems if PIE isn't upgraded cache handling-wise AND it stores its cache also in the File Store.

[Menneisyys]

I'm really looking forward to the new Windows Mobile 5 devices!
Would I be making a huge mistake if I were to buy an HP hx4705 now as opposed to waiting for something better down the road?

I currently have an HP 5550 and am using all 128MB of its memory, which has kept me from getting a newer iPAQ. The whole persistent storage thing is intriguing, and perhaps I could "fit" on an hx4705, but I don't want to buy something that might be replaced any time in in the near future.

I would get the hx4700 now that it's certain it'll receive the WM2005 upgrade.

[alex_kac]

About the "everything in ROM so you can really turn it off" proposal - while that would be really neat, you'd have to have literally everything short of temp files in ROM to make it workable, and with Flash ROM being so much slower it could bring on some serious performance issues... still that's been discussed to death elsewhere.

With the current crop of even high-end devices (I speak of devices like the hx4700 and the Pocket Loox 720), I don't see it feasible to come up with a browser that stores its cached stuff into the Persistent Storage to work at least reasonably fast. (Future devices with greatly enhanced File Store writing/file creation speeds will definitely be better in this respect.)

I've done quite much of speed benchmarking and found out (http://www.pocketpcthoughts.com/forums/viewtopic.php?t=36376) that putting the Pocket Internet Explorer (PIE) cache in current VGA devices' File Store can cause a performance degradation of an order of magnitude. If PIE's caching model is made better in the new op. system version, "old", "legacy" programs like Netfront will still have big problems when run from the File Store because of the cache.

If, on the other hand, the cache will be configurable to be put even in RAM, everything will be OK.

The same stands for some other "legacy" apps too - for example, SimpleSMS. It's just intolerably slow run from the File Store because it does a lot of file creation/write behind the scenes.

Bottom line: with current (hyperslow) File Stores there will be problems if PIE isn't upgraded cache handling-wise AND it stores its cache also in the File Store.

Here are the facts:

1) The OS in WM5 has been greatly optimized to read/write data to the filestore.
2) PIE DOES write its cache to ROM. It feels very fast on this device which has a ROM much slower than the 4700. No slower than my 4700, that's for sure.
3) Many apps WILL have to updated to take into consideration reading/writing to the file store.

Guys, this is a major, major OS update - both for the user and the developer. FAR more major than SE was. But just like SE, applications will have to be updated. The nice thing is that for the vast majority of those apps, only a few things will have to be updated and it will be far easier to do than Landscape/High DPI was. And in this case, some of the things like reading/writing files is standard fare for any app that wants to optimize its file read/write speed on any platform.

Your post makes it sound like we don't really know how things are implemented. We do. I've got a device sitting right here with WM5 on it. I can tell you first hand what it took for me to port PI to WM5. I can say that at least for PI I had to make no changes whatsoever to our file handling for the persistent store.

I know a lot of the people on this thread are very very skeptical because of the way Palm did things and also hearing different things that make it sound like MS just couldn't have gone this route. The fact is - all WM5 devices will have a persistent store. The fact is that on CURRENT devices, WM5 will seem about as fast as WM2003 is. And the fact is that many apps will run without needing to be updated, but that being updated will improve the app's ability to run well on WM5.

I will also tell you my impression of using WM5 as a user. I don't use Pocket Excel or Word much, though I know those were improved dramatically - not so much with their features (charting, read only tables/images) but with document fidelity. I don't use Powerpoint (I prefer Apple's Keynote). But I like to use PIE, PI, Mail, PhatPad/Notes, etc... and they all work a bit better on WM5. I wasn't too crazy about the Soft Key interface (I hate them at first) and continued to dislike them until I actually used it on a piece of hardware, not just an emulator. I like them now for the simpler apps and for basic OS navigation. I find the OS fast and enjoyable to use. And this is on 2 year old hardware with a SLOW FlashRom. Imagine how well it would run on a 4700 or Dell x50.

Everyone has a right to be skeptical. I don't dispute that. And some people will find things they truly dislike about the new OS. Not a problem. I'm not an OS zealot. Afterall, I use Macs, PCs, Pocket PCs, and a Motorola Razr personally and professionally. But I find the negative tone about all this a bit misleading and as everyone who knows me well knows, I dislike misleading. That is the reason I'm posting here. It doesn't affect me either way if a user sticks with WM2003 or WM5 - as long as they use our software :roll:

So in conclusion to this very long post, I think a lot of you will find that by the time real WM5 devices hit the street, the necessary apps will be updated, the rest will run just fine, and you'll love not having to worry about your battery running out.

[Menneisyys]

And PIE uses about 2 MB, per page with MultiIE or PIEPlus or the like, not including cache.

Yes, PIE consumes a LOT of memory. For example, on a WM2003 device, it takes 24.97 Mbytes to render the 980k test HTML page here (http://menneisyys.freeweb.hu/BrowserMemoryTest/). That is, you can almost always consider an about 25-times memory need for a given HTML size.

[gibson042]

Yes, PIE consumes a LOT of memory. For example, on a WM2003 device, it takes 24.97 Mbytes to render the 980k test HTML page here (http://menneisyys.freeweb.hu/BrowserMemoryTest/). That is, you can almost always consider an about 25-times memory need for a given HTML size.
WOW. 25x can't be the norm, though, can it? Could you please do another experiment for me? Convert the page to standards-compliant and parse-friendly HTML 4 (doctype, html, head, body, and "&lt;/p>"s), and see how the memory use changes. Also, what is the ratio for a more common page (using, for example, this thread)?

[Menneisyys]

Yes, PIE consumes a LOT of memory. For example, on a WM2003 device, it takes 24.97 Mbytes to render the 980k test HTML page here (http://menneisyys.freeweb.hu/BrowserMemoryTest/). That is, you can almost always consider an about 25-times memory need for a given HTML size.
WOW. 25x can't be the norm, though, can it? Could you please do another experiment for me? Convert the page to standards-compliant and parse-friendly HTML 4 (doctype, html, head, body, and "</p>"s), and see how the memory use changes. Also, what is the ratio for a more common page (using, for example, this thread)?

Will experiment with other pages too. I've done other experiments, mostly with local HTML (help) pages in \Windows, and the runtime in-memory memory consumption of a given HTML file has always been at least an order of magnitude more than the original size of the files. I'll also compare different op. system version PIE's in this respect too. (So far, in speed, the PPC2k2 version has been the worst - even the Jornada 680 was faster at rendering pages.)

[gibson042]

Thanks a lot. I am a big fan of your studies/analyses, and will look forward to this one.

[alex_kac]

Now I'm looking at PIE right now on a WM2003SE VGA device using a tool that measure all the RAM it uses. Going to CNN.com its using up - with images - 2,969,072K. CNN's website is pretty hefty in size.

[T-Will]

Waitaminute... what's this about my alarms not working when I turn it off?!?

;-) :lol:

WHAT?!?! Why did they add this "feature"?!?!? This is tEh dumberest idea iVe' evAr heard!111 Good job M$$$$$$$$$$$$$$!!!!!!!!111111 :roll: :wink:

[gibson042]

Now I'm looking at PIE right now on a WM2003SE VGA device using a tool that measure all the RAM it uses. Going to CNN.com its using up - with images - 2,969,072K. CNN's website is pretty hefty in size.
Either you mean 2,969,072 bytes (and my 2 MB per page estimate was pretty accurate), or I really want your device (and its 3 GB of RAM :wink:).

[alex_kac]

woops - I meant bytes, not K :)

[Menneisyys]

Now I'm looking at PIE right now on a WM2003SE VGA device using a tool that measure all the RAM it uses. Going to CNN.com its using up - with images - 2,969,072K. CNN's website is pretty hefty in size.

The HTML file itself is 72kbytes; all the additional files (including images) 170k. Therefore, it's safe to say that a page with several images will consume about an order of magnitude more memory than the cumulative size of all its resources (HTML page, images, JavaScript files etc)

[Dalantech]

alex_kac,
Thanks for your post on WM5 -it's good to hear from someone who is actually using it on a device and not just an emulator. Only one thing to add: The ROM that HP used in the 2000 series iPaqs also seems to be high speed -the custom apps that HP ships with the device load very quickly after a hard reset and backing up my 2410 to the file store takes about 3 minutes (and I have close to 30MBs of apps and documents loaded).

[Cybrid]

Some remember my thread from PPCPassion about the file corruption in the BIS of my X5.....
http://delltalk.us.dell.com/supportforums/board/message?board.id=dellpda&amp;message.id=24414
There are always things that can go wrong. :!:

At present my X50V is structured with everything installed to the BIS and it aint all that slow. There is a lag but I've found that to be mainly from items like PocketRSS and some others...Not all. PI works quite well (P.S. Thanks Alex! beautiful software!)

I think this would be a welcome change for many a newbie/ palm convert who would otherwise "Help! I have no backup and my battery died!".

As for the 64Mb vs. 128Mb griping....this is irrelevant. This is what they decided. A day will come when our children will laugh at our 64/128 Mb devices much the same as we'd be amused if someone pulled out an old Casio B.O.S.S. with 64K. As a moderately advanced user, I find 64Mb limiting but workable. 128Mb would be amazing but I'm sure I could eventually outhog that too. Remember, use the RAM wisely, one must. -Yoda

[rasputinj]

I can't wait to get the Windows Mobile 5 with peristante storage and it will be nice to have a full off button. These 2 items will really fix most of my issues I have had with Pocket PCs.

[alex_kac]

I'll have to say - I haven't found any way to turn "off" my WM5 device except to remove the battery. I assume this will be a per-OEM thing with some special key-press.

[yankeejeep]

Alex, when you do the press-and-hold on your power button, does yours still toggle the screen light?

[alex_kac]

It does.

[ipaqgeek]

Okay, I'm the one who proposed something like this in the first place 6 month ago when Jason wrote his last article about memory that caused so much flack. I called it Core-dump ROM, and the idea was that all program storage existed in the ROM, and all RAM was reserved only for executing code. The advantage was:

1) Persistent storage - when off, everything in RAM is backed up to ROM.
2) Infinite off-state battery life. Right now DRAM, by nature, always consumes memory when your PPC is "off" because the RAM needs juice to keep the contents alive. That's why you'll lose everything if you're battery is low and then you forget to plug in your PPC that night. My new scheme litterally shuts the DRAM devices off to eliminate off-state battery drain.

So it looks like they're finally adopting this technology. Unfortunately it seems to me that they're doing it without an efficient way to back up the RAM. In fact, I'm not sure they're backing up the RAM at all when it goes into a true off-state.

So it begs the question... is the RAM being backed up (like a computer does when it automatically goes from "suspend" to "off")? If so, then part of the ROM will be reserved to backup the RAM.

That then begs the question: how much ROM is reserved to backup the RAM? 64Mb? If so, then a 64MB RAM / 128MB ROM device is really only 64MB RAM / 64MB ROM because 64Mb of the ROM is reserved to backup the ROM.

Also, if it is not backing up the RAM contents when it automatically goes from "suspend" to "off" (while sitting on my dresser for too long), then we're no better off than we were before - and so this whole scheme sucks. That may be okay for a smartphone to do that, but a PPC is used for so much more, and often I have valuable info in RAM that isn't saved.

That ain't true "persistent storage". That's more like "sometimes persistent storage, depending on whether you saved what you have in ram" storage.

There's some big questions that need answering. I for one would also be interested about how they plan on backing up the RAM to ROM when ROM write speeds are inherently so slow (perhaps a version of my Core-DumpROM chip with it's super parralleled distributing periphery?). Backing up RAM is easy to do with a smartphone that has very little RAM, but 64MB of RAM is an entirely different animal (save 64Mb to your fastest CF card and you'll see what I mean). The write bottleneck in FlashROM occurs at the bit, not the bus, so a radical new periphery would need to be put in place for this to work right.

[alex_kac]

Okay, I'm the one who proposed something like this in the first place 6 month ago when Jason wrote his last article about memory that caused so much flack. I called it Core-dump ROM, and the idea was that all program storage existed in the ROM, and all RAM was reserved only for executing code. The advantage was:

1) Persistent storage - when off, everything in RAM is backed up to ROM.
2) Infinite off-state battery life. Right now DRAM, by nature, always consumes memory when your PPC is "off" because the RAM needs juice to keep the contents alive. That's why you'll lose everything if you're battery is low and then you forget to plug in your PPC that night. My new scheme litterally shuts the DRAM devices off to eliminate off-state battery drain.

So it looks like they're finally adopting this technology. Unfortunately it seems to me that they're doing it without an efficient way to back up the RAM. In fact, I'm not sure they're backing up the RAM at all when it goes into a true off-state.

So it begs the question... is the RAM being backed up (like a computer does when it automatically goes from "suspend" to "off")? If so, then part of the ROM will be reserved to backup the RAM.

That then begs the question: how much ROM is reserved to backup the RAM? 64Mb? If so, then a 64MB RAM / 128MB ROM device is really only 64MB RAM / 64MB ROM because 64Mb of the ROM is reserved to backup the ROM.

Also, if it is not backing up the RAM contents when it automatically goes from "suspend" to "off" (while sitting on my dresser for too long), then we're no better off than we were before - and so this whole scheme sucks. That may be okay for a smartphone to do that, but a PPC is used for so much more, and often I have valuable info in RAM that isn't saved.

That ain't true "persistent storage". That's more like "sometimes persistent storage, depending on whether you saved what you have in ram" storage.

There's some big questions that need answering. I for one would also be interested about how they plan on backing up the RAM to ROM when ROM write speeds are inherently so slow (perhaps a version of my Core-DumpROM chip with it's super parralleled distributing periphery?). Backing up RAM is easy to do with a smartphone that has very little RAM, but 64MB of RAM is an entirely different animal (save 64Mb to your fastest CF card and you'll see what I mean). The write bottleneck in FlashROM occurs at the bit, not the bus, so a radical new periphery would need to be put in place for this to work right.

Here is what you're asking in a nutshell. Is there a "Hibernate" feature. As far as I can tell - NO. There is a suspend or off only. RAM is never used as storage. So yes, it is a persistent store. Just like your desktop's hard drive and real RAM.

If anyone is having any trouble understanding how this works - look right in front of them. How your desktop works now is how the Persistent store works on WM5. FlashROM == Hard drive. RAM == RAM. That's all there is to it.

[ipaqgeek]

I also just want to say about XIP (execute in place)... XIP using FlashROM results in a slower device and if fully implemented, can decrease the life of your Flash ROM (which has limited writes). I don't think that's what they're doing here. I could be wrong, but I believe it's a technology that's really reserved for a future memory technology like FRAM or MRAM (stuff that's not currently feasible, but will be someday) that has unlimited writes and runs at DRAM or faster speeds.

I've read posts that insist that XIP and persistent storage are that same thing. That is not true. XIP uses persistent storage - but not all persistent storage setups use XIP. In fact. none of the persistent storage devices currently in existence (that I know) use XIP - at least not a full implementation of it. As has been mentioned before - smartphones use a persistent-storage-like setup - but they do not use XIP. They copy their ROM contents into RAM and execute them there.

[ipaqgeek]

Lastly, before I sign off tonight.. let me say Kudos for Microsoft for making alarms more reliable than ever. Now we can reliably count on our devices NOT sounding off their alarms. Funny. Think it will come up Jan 1 2005 after you power it back on each time? Something in there is ticking - it just isn't very smart, apparently. Maybe they should talk to the guys in Japan that made my watch.

[alex_kac]

Lastly, before I sign off tonight.. let me say Kudos for Microsoft for making alarms more reliable than ever. Now we can reliably count on our devices NOT sounding off their alarms. Funny. Think it will come up Jan 1 2005 after you power it back on each time? Something in there is ticking - it just isn't very smart, apparently. Maybe they should talk to the guys in Japan that made my watch.

Why do you say that? WM5 should if anything, greatly improve alarms. In fact, as far as I can see - its very good on WM5.

[Jason Lee]

I also just want to say about XIP (execute in place)... XIP using FlashROM results in a slower device and if fully implemented, can decrease the life of your Flash ROM (which has limited writes). I don't think that's what they're doing here. I could be wrong, but I believe it's a technology that's really reserved for a future memory technology like FRAM or MRAM (stuff that's not currently feasible, but will be someday) that has unlimited writes and runs at DRAM or faster speeds.

I've read posts that insist that XIP and persistent storage are that same thing. That is not true. XIP uses persistent storage - but not all persistent storage setups use XIP. In fact. none of the persistent storage devices currently in existence (that I know) use XIP - at least not a full implementation of it. As has been mentioned before - smartphones use a persistent-storage-like setup - but they do not use XIP. They copy their ROM contents into RAM and execute them there.

right. Not even you desktop pc is xip. everything is copied to ram first. And it technicaly isn't even executed from ram. as the cpu uses the data in ram it is copied the the processor's cache then put back into ram when the cpu is done with it for the moment. (man, i've had too many computer theory classes. lol)

the suspend mode on the new wm 5.0 devices will be just like now. ram will still have power. when you put it into true off mode it will shutdown just like your pc does so there will be nothing in ram to back up. when you turn it back on it will boot up just like you'd done a soft reset on your current ppc.

it's very simple. they will work just like a desktop.

[ipaqgeek]

Here is what you're asking in a nutshell. Is there a "Hibernate" feature. As far as I can tell - NO. There is a suspend or off only. RAM is never used as storage. So yes, it is a persistent store. Just like your desktop's hard drive and real RAM.

If anyone is having any trouble understanding how this works - look right in front of them. How your desktop works now is how the Persistent store works on WM5. FlashROM == Hard drive. RAM == RAM. That's all there is to it.

Ah, but my laptop does have a Hibernate feature. It saves what's in RAM. That's persistent storage. You're saying WM5 doesn't do this? Then what's in memory isn't persistent. RAM is memory. At best this should only be called persistent ROM.

So, like I said. This feature is hardly any better than what they had before - unless I hold down the off button every time I shut it off, and wait how long for it to reboot? That means I have to wait how much longer for PI to reboot evertime I turn it back on, so I can look at my contacts using my favorite program (ps - Yes, PI is my favorite program)?

[surur]

It must be really irritating to have so many people really miss the point but still be so opinionated, especially when they build whole edifices on their unwarranted conclusions.

Surur

[alex_kac]

Here is what you're asking in a nutshell. Is there a "Hibernate" feature. As far as I can tell - NO. There is a suspend or off only. RAM is never used as storage. So yes, it is a persistent store. Just like your desktop's hard drive and real RAM.

If anyone is having any trouble understanding how this works - look right in front of them. How your desktop works now is how the Persistent store works on WM5. FlashROM == Hard drive. RAM == RAM. That's all there is to it.

Ah, but my laptop does have a Hibernate feature. It saves what's in RAM. That's persistent storage. You're saying WM5 doesn't do this? Then what's in memory isn't persistent. RAM is memory. At best this should only be called persistent ROM.

No, that's not persistent storage. Its persistent workspace.
So, like I said. This feature is hardly any better than what they had before - unless I hold down the off button every time I shut it off, and wait how long for it to reboot? That means I have to wait how much longer for PI to reboot evertime I turn it back on, so I can look at my contacts using my favorite program (ps - Yes, PI is my favorite program)?

I don't think you're understanding it at all. Not even close :(

Right now on WM2003, RAM holds two areas. One is Storage of data - databases, DLLs, exes, files, etc... The other is Execution Memory - or Program memory. This is where apps get loaded into RAM, variables are held, etc.. When you press the power button, the device goes into "suspend" mode where the CPU/RAM get put into a low power state. Nothing is lost in this state, but of course if you take out your battery or run out of juice - all is lost. ROM on these devices holds the OS with a "storage card" area as well.

On WM5, RAM is Execution Memory ONLY. That's where apps run, variables are held, etc... It does not store databases. It does not store files. Just like the desktop. The Persistent Store is now what used to be the "FileStore" or "FlashROM". It holds both the OS in the ROM portion, as well as all your apps, databases, files, and so on. When you press the power button, the device goes into "suspend" mode where the CPU/RAM get put into a low power state. In this mode your RAM still has its contents (just like in WM2003) so that when you resume (by pressing the power button), your apps are still there running, etc.. So far, the user experience is IDENTICAL to WM2003. But here is where it differs. If the juice goes out or you take the battery out - NONE of your database, files, settings, apps are lost. They still exist in the Persistent Store.

So to recap:
Everything is still instant on. Everything works just like before to the user - except you're data is safe now. Persistent STORE == data/apps/files, just like your desktop hard drive. Please note this is NOT Hibernation and Hibernation is not something that makes one iota of sense on these devices.

[gibson042]

Another question just popped into my mind regarding WM5 devices. Why won't they be able to wake up for alarms from full off? The obvious answer is "how could they know to wake up if they are truly off?", but there is a parallel in desktop computers. Even when "off", an ATX mainboard receives a trickle of 5 V "standby" power from its power supply. The BIOS and wakeup-capable components are kept active with this power, and the computer turns on when a wakeup event (power button press, keyboard/mouse activity, wake-on-LAN signal, etc.) occurs.

My VIA EPIA M10000 has a feature called "RTC Alarm Resume" which uses the board's clock to trigger a wakeup event and turn on the computer at a scheduled time and date. In a Pocket PC with similar hardware support, the OS could schedule a wakeup at (well, just before) the time and date of the next alarm whenever it is turned off.

This would be useless to current devices, but very beneficial under the new system. Is there no plan for scheduled wakeup from full off?

P.S. I know that on my proposed hardware, off is still not really off. However, the power required to operate a clock is so low that the difference could very well be indistinguishable from the normal idle loss associated with (rechargeable) batteries.

[ipaqgeek]

Ah, but my laptop does have a Hibernate feature. It saves what's in RAM. That's persistent storage. You're saying WM5 doesn't do this? Then what's in memory isn't persistent. RAM is memory. At best this should only be called persistent ROM.

No, that's not persistent storage. Its persistent workspace.
So, like I said. This feature is hardly any better than what they had before - unless I hold down the off button every time I shut it off, and wait how long for it to reboot? That means I have to wait how much longer for PI to reboot evertime I turn it back on, so I can look at my contacts using my favorite program (ps - Yes, PI is my favorite program)?

I don't think you're understanding it at all. Not even close :(...

...Everything is still instant on. Everything works just like before to the user - except you're data is safe now. Persistent STORE == data/apps/files, just like your desktop hard drive. Please note this is NOT Hibernation and Hibernation is not something that makes one iota of sense on these devices.
Thanks for explaining that.

I actually have a pretty good working understanding of how WM2003 memory works (none of that information was new to me). The discussion of suspend vs. hibernate did mess me up because I got the two mixed up when I read your comments (sorry). My fault.

It also wasn't clear to me that this new scheme didn't save the workspace - everyone just said what you said:"your data is safe now".

But is it really? If I'm editing an Excel file (which I do almost daily), and the machine shuts off, then on my PC (a notebook) I really am totally data safe because it backs up my workspace too. With WM5 I loose those changes.

Although you didn't say "it works like your desktop", others did and well, it doesn't. At least not like mine.

That said, I'm pretty underwhelmed - even disappointed with the change because I use GPS - and it requires most all of 64M RAM, so I guess I'll be going to Pocketpctechs.com to get that upgraded on future devices. And, while the memory scheme is now better in some ways, I already nearly had most of the same benefits of using this memory scheme by storing all my programs and databases on a flash card. - so like I said above "This feature is hardly any better than what they had before".

With people saying it worked like my PC does, making my data safe, and that this was a huge change, I got all excited. Bummer.

[ipaqgeek]

Lastly, before I sign off tonight.. let me say Kudos for Microsoft for making alarms more reliable than ever. Now we can reliably count on our devices NOT sounding off their alarms. Funny. Think it will come up Jan 1 2005 after you power it back on each time? Something in there is ticking - it just isn't very smart, apparently. Maybe they should talk to the guys in Japan that made my watch.

Why do you say that? WM5 should if anything, greatly improve alarms. In fact, as far as I can see - its very good on WM5.

I'll take your word for that. You would know. Thanks! It's good news that alarms will be greatly improved - even if it took some of my anti-microsoft sarcasm to bring that news out.

[Jason Dunn]

I can't believe this thread is still going with all these insane conclusions and faulty leaps in logic...I've never seen anything like this in the history of this site. 8O Frankly, it's depressing.

Why won't they be able to wake up for alarms from full off? The obvious answer is "how could they know to wake up if they are truly off?", but there is a parallel in desktop computers. Even when "off", an ATX mainboard receives a trickle of 5 V "standby" power from its power supply.

Your desktop computer is plugged into a wall with an essentially infinite power source. Your Pocket PC is not. If you want it to trigger alarms and whatnot, you'll just put it into suspend mode like you do today. It would be utterly stupid for Microsoft to implement a true off mode that STILL used battery power...which is what you're suggesting. It just doesn't make any sense.

If any of you guys want to see how this works, go find a Windows Mobile Smartphone and after 60 seconds you'll grasp it fully. This is not voodoo magic - some of you guys are completely over-thinking it. :?

[christak]

Well, I've been gone for a few days and just read all 12 pages of this thread... WM5 looks very interesting and I'm anxious to get a look at it on my x50v. (...and lots of folks here don't seem to be reading very closely...)

I'm guessing that installing apps to SD or CF memory cards will still be required for those of us with large numbers of apps (>80) on our PPCs... However, with all files (even the .dll's etc that end up in the Windows folder) being stored in ROM, RAM will be available to run just about anything and if the battery goes dead -- no big deal...

Bring it on...

8)

[gibson042]

I can't believe this thread is still going with all these insane conclusions and faulty leaps in logic...I've never seen anything like this in the history of this site. 8O Frankly, it's depressing.
That's the second time you've insulted me in this thread. I have made neither insane conclusions nor faulty leaps in logic, and have backed up all of my claims with the best evidence available to me.

Your desktop computer is plugged into a wall with an essentially infinite power source. Your Pocket PC is not. If you want it to trigger alarms and whatnot, you'll just put it into suspend mode like you do today.
This real-time clock (http://www.wsdmag.com/Articles/ArticleID/9276/9276.html) has a quiescent current draw of 0.25 µA, and this 8-bit comparator (http://eshop.engineering.uiowa.edu/NI/pdfs/00/53/DS005371.pdf) has one of 80 µA. To keep and check the standard 16-bit time would thus require 200 µA (including a 40 µA fudge factor for miscellaneous minor functions). A Dell Axim X50v, which is definitely getting an update to 5.0 and is known for sub-par battery life, could maintain this ultra-low power "off" state for 229 days with its standard 1100 mAh battery, and would take a month and a half to even use 20% of a full charge.

In exchange for this negligible power drain in an "off" state, thousands of technical support conversations and hundreds of forum postings about "why didn't my alarm go off; I thought they were finally fixed!" can be avoided. Not only that, but this scheme avoids unnecessary battery drain because it bypasses the OS entirely until it is needed. Just how long can a device stay in suspend, using the CPU, RAM, communication buses, etc. (albeit in low-power mode)? It is possible, and I say desirable, to turn off those non-vital components when all they are doing is waiting.

It would be utterly stupid for Microsoft to implement a true off mode that STILL used battery power...which is what you're suggesting. It just doesn't make any sense.
Is that your problem... that "off" mode using battery power would be a stupid decision from Microsoft (:shocked!:)? Off mode uses battery power now, and lots of it. You can only view one web page at a time. Simple tasks can take a dozen taps to complete. The close button minimizes! If you don't like the suggestion for technical reasons, please state them. We can argue semantics forever.

If any of you guys want to see how this works, go find a Windows Mobile Smartphone and after 60 seconds you'll grasp it fully. This is not voodoo magic - some of you guys are completely over-thinking it. :?
I understand how it works. I'm merely asking how much thought has been put into the consequences of this change, and if manufacturers intend to take advantage of the opportunities provided by it.

[Jon Westfall]

This thread is just getting a bit too heated and probably just needs to die. I don't think Jason meant to insult anyone. I was a bit confused when I read the way the post was worded, and your clarification helped.

[Jason Lee]

good greif you people make my head hurt....

ok let me try this.
any of you ever have one of the old ipaq 3600 or 3700? or a toshiba 740 or 755?
remember those little switches on the bottom? the ones that made all your data go away?

ok, here comes the confusing part so try to keep up.

when the new wm 5.0 devices fall asleep, or power them selves off, or if you push the power button it works exactly like they do now. ok?

now, if you want to put you pocket pc in a drawer and not use it for 6 months you flip that little switch. right? so you battery doesn't get permanently destroyed.
that is the only reason you will eeeeeevvvvveeeerrr want to use the new off feature.

now the cool part with the new wm 5.0 is that 6 months later when you pull your ppc back out and flip that switch back on everything is just as you left it! you files, contacts, installed programs, everything!

no one in this forum should have ever mentioned this new power off "feature" because it is not a feature, it is a side effect of having everything in rom.

putting the new wm 5.0 in off mode is the same as taking the battery out. you are not gonna ever do that unless you are gonna store it for along time and want to save the battry.


ok now for ram vs rom...

when you install a program to your desktop pc where does everything go, the exe, the dlls, everything? ram or hard drive?

when you install a program on your new wm 5.0 device where does everything go, the exe, the dlls, everything? ram or rom?

now here is a tip. ram == ram. hard drive == rom.

It really is that simple. There is nothing else to it. To you it is going to work exactly the same as your current ppc.

I am finished watching this topic... It hurts me so.

[huangzhinong]

Is that your problem... that "off" mode using battery power would be a stupid decision from Microsoft (:shocked!:)? Off mode uses battery power now, and lots of it. You can only view one web page at a time. Simple tasks can take a dozen taps to complete. The close button minimizes! If you don't like the suggestion for technical reasons, please state them. We can argue semantics forever.


Your idea actually is a good idea, although MS won't accept it. You proposed a deeper suspend mode, which has new requirement for hardware.

By the way, Jason at least attacked me twice in this forum. So you are not alone.

**excessive quoting edited out by moderator JD - please don't double-quote long messages. ***

[gibson042]

I planned to write no more on this, but I would like to make a clarification. Knowing that a BIOS wakeup is easy to implement, can function on virtually no power, and exists on at least the EPIA line of PC mainboards, I wondered if it might be a feature of current hardware (and if so, whether the new OS would make use of it or not). No existing PDA that I'm aware of does anything like this (it would be useless without OS support anyway), but that doesn't mean they couldn't. Intel's PXA27x processor family natively supports USB hosting and USB On-The-Go; only a handful of devices include the former, and none the latter.

In fact, after reading a little more information on Intel PXA27x Processor Family Power Requirements (ftp://download.intel.com/design/pca/applicationsprocessors/applnots/28000502.pdf), it seems that everything I've talked about is already implemented! Deep sleep mode powers only the timekeeping oscillator, real-time clock, and power management unit, on a current of just 6 µA for the processor and perhaps 50 µA for an external power management integrated circuit (PMIC) and "microamps" for DRAM in deep-power-down mode... cumulatively lower than my original estimate, and without any new hardware. A wakeup event brings the system out of deep sleep, with one possible wakeup event being "an interrupt from a timer in the real-time clock unit".

Anyway, I'm now done with this. Time will tell which features are available and which are not.

[Stelios]

Hi,

why is it so difficult for Microsoft and all of the manufacturers to hide from us poor developers and users all of the power management of the Pocket PCs?

For me persistent storage means an AUTOMATED HIBERNATION method that will fool-proof the major power Pocket PC flaw. What I mean is that the devices should always work in RAM (storage &amp; programs) and when the back-up battery reaches a threshold ALL RAM should be copied (compress it if you like!) in FLASH. When the power is back on it, then copy it back into RAM.

I am sure that the extra cost (if any) would be perfectly acceptable from the users.

[Menneisyys]

1) The OS in WM5 has been greatly optimized to read/write data to the filestore.
2) PIE DOES write its cache to ROM. It feels very fast on this device which has a ROM much slower than the 4700. No slower than my 4700, that's for sure.
3) Many apps WILL have to updated to take into consideration reading/writing to the file store.

(Sorry for only answering now. Just looked up the thread to be able to link it from somewhere else.)

That's great news.

(I'd still add that the hx4700 also has a very slow-to-write-to/create individual files file store, at least under WM2003SE - much slower than any current mainstream - non-high-end - memory card. It's still nice to see that one of the biggest problems - that is, the limited ability to move the cache to somewhere else - with PIE's will be/is fixed in WM5.)