RAM vs ROM: which is better?

[mikemccand]

Hi,

I'm going to buy my first Pocket PC PDA soon -- I want a VGA w/ 624 Mhz Intel CPU, and I'm waiting to see how Dell's Axim X50 stacks up against HP's Ipaq hx4700/4705.

One big difference between the two is X50 will supposedly have 128 MB RAM but the hx4700/4705 has 64 MB RAM (both will have 128 MB ROM) -- is this a "weakness" of the Ipaq? What does it mean in practice? There's no "virtual memory" (backing to ROM or something) right? So I can only run so many programs at once?

I want mostly to use it for GPS and secondarily as PIM.

[ADBrown]

Hi,

I'm going to buy my first Pocket PC PDA soon -- I want a VGA w/ 624 Mhz Intel CPU, and I'm waiting to see how Dell's Axim X50 stacks up against HP's Ipaq hx4700/4705.

One big difference between the two is X50 will supposedly have 128 MB RAM but the hx4700/4705 has 64 MB RAM (both will have 128 MB ROM) -- is this a "weakness" of the Ipaq? What does it mean in practice? There's no "virtual memory" (backing to ROM or something) right? So I can only run so many programs at once?

I want mostly to use it for GPS and secondarily as PIM.

In this case, more RAM basically just means more storage. Yes, you can only run so many programs at once, but the limit is so high you probably won't notice it. Personally, I'd go with the X50 for the extra memory and better video controller, but that's just me.

[WyattEarp]

If your going to use is mainly for GPS and secondly for PIM then either unit will do you well. At this point price may be the deciding factor as long as both are pretty much the same (although this still remains to be seen, the X50 isn't out yet.)

It seems that many people only use the FlashROM to backup their device but IMHO especially since it isn't a lot it would be better served to use it to install programs on and backup to an SD card for safe keeping. That's how I use my 17MB of FlashROM, leaving more RAM for running programs along side the ones I choose to put in RAM itself.

I wouldn't consider 64MB a weakness but considering the hx4700 is the successor to the h5555 you would think they would have stuck with the 128MB of RAM and added the 128MB of FlashROM as an incentive to upgrade to the new device.

But that aside the next step is a change in the memory model for future PPCs. It is to increase FlashROM and decrease RAM and using RAM for program execution only. So any vendor that creates a 128MB RAM/128MB FlashROM device will get a lot of sales.

The bottom line is the more memory the better RAM or FlashROM. Just make sure that the FLashROM is capable of running programs and not just storing files. All FlashROM are not created equal.

[Sven Johannsen]

There isn't a PPC today that runs programs out of Flash, ROM or external storage. You can install programs to it, like a hard drive on a PC, but it still runs out of RAM. There are things that need to 'load' out of RAM when the device is reset, like SIPS, Today Screen enhancements, that may have a problem loading from Flash, because the flash isn't available soon enough. So some programs 'need' to be stored in the storage part of RAM, so the can run right out of the program side of RAM. Whatever is in RAM must be kept alive, which takes power. Actually everything in RAM is kept alive, so the more of it you got, the more power is taken just keeping it alive...all the time.

Internal ROM is good because you can use it like a hard drive, keeping your oft used programs in it while using removable Flash as storage for documents, music, video's, Map data, etc, without worrying about where the programs that use them are.

So, More RAM is cool, but it has it's cost. More ROM is neat too, especially if it is internal.

[surur]

My research on the XDA 2 (128 Mb ram) shows 2 things:

1) You can only run 32 processes in any case, before win ce closes a process, so it doesn't matter how much ram you have, you can only run so many programs.

2) There also seems to be a soft limit at 32MB of actually used program memory being used, no matter how much is allocated, before win ce again closes programs. I dont know if this limitation is still in wm2003 SE, but knowing microsoft they never fix these things.

Lastly built-in storage tends to be useless, as it will never be enough for a large GPS map or a backup of your memory. Its much better for installing programs in rom, but using 80Mb of rom for win ce programs seems a bit excessive.

To summarise, 128Mb ram wont let you run more software at one, but it will increase the amount of files you can keep synchronised in your My documents folder, which seems to me to be some benefit after all.

Surur

[mikemccand]

Thanks for the responses everyone! It sounds like realistically, esp. if I'm focusing on just GPS, 64 MB RAM would be plenty.

I do plan on getting a CF GPS and a large SD storage card to hold the maps (ie not using internal ROM only to hold maps). I currently have a "dedicated" handheld GPS (Garmin GPS V) which I love except I basically want "more horsepower".

Seems like maybe the Ipaq hx4700/4705 chose 64 not 128 MB RAM to try to help battery life (that and a large battery); will be interesting to see how Axim X50 does on battery life.

It would be neat if external flash cards could someday offer additional RAM.

Here's a follow on question: do apps on Pocket PC tend to consume alot of RAM? I know on my Windows XP desktop there are some apps that are hogs (I think they must have leaks) -- does this tend not to happen on Pocket PC because developers are more careful?

[WyattEarp]

Here's a follow on question: do apps on Pocket PC tend to consume alot of RAM? I know on my Windows XP desktop there are some apps that are hogs (I think they must have leaks) -- does this tend not to happen on Pocket PC because developers are more careful?

Apps can take up anywhere from a few KB to a few MB. But simply put they usually don't. Most vendors try to keep their apps small and without memory leaks but it does happen from time to time. Memory leaks usually get solved when the vendor figures out how it's happening in the first place. Other programs are memory hogs or just outright large programs (TextMaker for example takes up about 7.2MB 8O but it has all the bells and whistles and replaces the anemic Pocket Word).

So you have lots of choices when it comes to apps just get the ones that serve you best. Sometimes memory hogs can't be helped especially when they do what you need.