Windows Phone Thoughts - Daily News, Views, Rants and Raves

Check out the hottest Windows Mobile devices at our Expansys store!


Digital Home Thoughts

Loading feed...

Laptop Thoughts

Loading feed...

Android Thoughts

Loading feed...




Go Back   Thoughts Media Forums > WINDOWS PHONE THOUGHTS > Windows Phone Articles & Resources

Reply
 
Thread Tools Display Modes
  #1  
Old 07-08-2005, 04:25 AM
Janak Parekh
Editor Emeritus
Janak Parekh's Avatar
Join Date: Aug 2006
Posts: 15,171
Default PDAgold.com on Memory in Pocket PCs

<div class='os_post_top_link'><a href='http://www.pdagold.com/articles/detail.asp?a=243' target='_blank'>http://www.pdagold.com/articles/detail.asp?a=243</a><br /><br /></div><i>"A vast majority of PDA owners have some experience with personal computers and know at least something about the basic elements, such as the memory. However, if such a user tries to apply the knowledge on pocket computers, he may be rather confused. This article explains the basic terms, describes different types of memory used in pocket computers and main differences between them."</i><br /><br />Veteran users probably know all there is in the article, and Pavel doesn't go into the details of WM5's persistent storage features. However, for those of you who have recently obtained a new Pocket PC, this is an excellent overview of both the hardware and software aspects of both RAM and ROM and what it means for you.
 
Reply With Quote
  #2  
Old 07-08-2005, 05:58 AM
ipaq_wannabe
Thinker
Join Date: Apr 2004
Posts: 392
Send a message via MSN to ipaq_wannabe

so, what happens to the memory if you have exceeded the number of writes/rewrites?
 
Reply With Quote
  #3  
Old 07-08-2005, 06:13 AM
Gerard
Pontificator
Join Date: Feb 2002
Posts: 1,043

I suspect that when the write limit of flash memory is reached, or approached and errors start becoming more than irritating, it becomes time to 'upgrade' to a new device.

I've been waiting for someone, at Microsoft or elsewhere, to come out and offer some reassurance that ROM being the main area for saving temporary and more permanent (if perhaps often updated and re-saved) documents is 'safe' or at least reliable enough for, say, 5 years' use. I realise that 5 years is a long, long time for most of us. My X5 is getting long in the tooth, and it's still far, far less than that old. My Casio EG-800 is still somewhat functional and my kid uses it several times a week, and it's not quite 5 years old.

But I do run into people who are still using the first series of iPAQs, and the odd Jornada or Casio from 2000 as well. These kinds of users are the more average sort, not the limit-pushers and early-adopters many here are. And their needs should be honoured.

So, is flash ROM a safe place for daily use for 5 years, including web browsing temp files, email, documents, installed software, and all the many other bits and pieces which make up the write-life of an average PPC? Or will it fall apart, leaving us with paperweights in shiny, almost-new shells? If the latter, I guess a big wallet will be the order of the day, and screen protectors will hardly be any more relevant than backup software.
__________________
Gerard Ivan Samija
 
Reply With Quote
  #4  
Old 07-08-2005, 07:11 AM
ipaq_wannabe
Thinker
Join Date: Apr 2004
Posts: 392
Send a message via MSN to ipaq_wannabe

so, how long could one characterize a 100,000 rewrites memory?

my handheld is an Axim x50v - and they say that the BIS has about that approximate amount of rewrites -

so, assuming that you work on 10 files a day (stored in BIS)...

assume that you save the file 10 times a day per use (those periodic saves)...

that would give us about 2.7 years of a lifetime, right?

which is basically the average time most users change handhelds - i usually upgrade in about between a year and a year-and-a-half...

but dont you think manufacturers should give us more value for our money? most HDDs have about years/decades of MTBFs...
 
Reply With Quote
  #5  
Old 07-08-2005, 03:22 PM
Janak Parekh
Editor Emeritus
Janak Parekh's Avatar
Join Date: Aug 2006
Posts: 15,171

No, it's not so bad. Most flash memory controllers optimize the writes to be over the entire space of the media, so that if you rewrite a file, it may actually go somewhere else so that no one space on the flash is rewritten too much. The last time we did calculations on the board, we found that for most people it would exceed 5+ years of active use (IIRC; they weren't scientific, though).

--janak
 
Reply With Quote
  #6  
Old 07-08-2005, 05:01 PM
surur
Mystic
Join Date: Aug 2006
Posts: 1,734

Memory card corruption is an increasingly common problem. How many post down we see that goes "Everything on my card has disappeared!".

We all blame the card manufacturer and the OS, but I wonder whether we are not running into this fundamental problem more often than we think.

Surur
__________________
Windows Mobile Power User
 
Reply With Quote
  #7  
Old 07-09-2005, 12:58 AM
ipaq_wannabe
Thinker
Join Date: Apr 2004
Posts: 392
Send a message via MSN to ipaq_wannabe

Quote:
Originally Posted by Janak Parekh
No, it's not so bad. Most flash memory controllers optimize the writes to be over the entire space of the media, so that if you rewrite a file, it may actually go somewhere else so that no one space on the flash is rewritten too much. The last time we did calculations on the board, we found that for most people it would exceed 5+ years of active use (IIRC; they weren't scientific, though).

--janak
could this be seen somewhere? URL maybe?
 
Reply With Quote
  #8  
Old 07-09-2005, 10:16 AM
Menneisyys
5000+ Posts? I Should OWN This Site!
Join Date: Jun 2007
Posts: 5,067

Quote:
Originally Posted by Gerard
So, is flash ROM a safe place for daily use for 5 years, including web browsing temp files, email, documents, installed software, and all the many other bits and pieces which make up the write-life of an average PPC?
Yes and no. With devices like the iPAQ rx3xxx, or, to a much lesser degree, the hx4700 (see for example this thread), PIE (and other) cache shouldn't be put in the File Store. Not only wiull it become very-very-very-very-very slow, but also these devices, especially the Samsung flash controller in the iPAQ rx3xxx, will be damaged from even several hundred (!) write cycles.

Some even say (see lorettaboy's posts here) that HP doesn't release the much more write-to-the-filestore-instensive WM5 upgrade for the rx3700 series because of this:

"There is a very good reason for HP not to upgrade the rx3700 series to WM 5.0. Have you all forgotten about the filestore problem? A decent percentage of all rx3700's have this problem, I should know, I had 3 rx's in a row die because of this. And since WM 5.0 will be using the filestore as the primary data store, having it fail would be detrimental. I honestly don't know why HP has not pulled this device yet.
So, I think it is easy to see why it is in HP's best interest not to release an upgrade for this particular model."
 
Reply With Quote
  #9  
Old 07-09-2005, 10:20 AM
Menneisyys
5000+ Posts? I Should OWN This Site!
Join Date: Jun 2007
Posts: 5,067

Quote:
Originally Posted by ipaq_wannabe
Quote:
Originally Posted by Janak Parekh
No, it's not so bad. Most flash memory controllers optimize the writes to be over the entire space of the media, so that if you rewrite a file, it may actually go somewhere else so that no one space on the flash is rewritten too much. The last time we did calculations on the board, we found that for most people it would exceed 5+ years of active use (IIRC; they weren't scientific, though).

--janak
could this be seen somewhere? URL maybe?
I can second this: I've also worked on SmartCard (which are based on EPROM) projects as a developer/planner. Even in the (comparatively to a Flash ROM memory card) very dumb SmartCards it's possible to 'map out' memory areas that, over time, became faulty. Flash cards (and file stores - not those of Samsung, seemingly :devilboy: ) work the same way.

I've been using flash ROM cards actively (writing all the time - for example, constant MP3 recording) for long years for my digicams and PDA's. None of them have broken on me. This means their protection and dynamic remap circuitry is working OK.
 
Reply With Quote
  #10  
Old 07-09-2005, 06:47 PM
Gerard
Pontificator
Join Date: Feb 2002
Posts: 1,043

Thanks a lot for the clarifications Menneisyys. This confirms my feeling about waiting, not buying an X50v nor a Loox 720, as it is yet unknown whether these devices' flash ROM will thrive under WM5.0. I'd rather sit it out, see what the newer models behave like and also how well those two upgrade. Not being anything remotely 'wealthy' I just can't afford a bad purchase.
__________________
Gerard Ivan Samija
 
Reply With Quote
Reply


Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT +1. The time now is 08:53 AM.