Re: What is the deal with 64 MB of ram?


"mike" <spamme9@xxxxxxxxx> wrote in message news:_mHZj.24$4c.18@xxxxxxxxxxx

I know that there are more new devices with 128MB, but why is the progress
so slow? Or is that operating system limitation?

It's all about power.
It takes power to save the ram contents when the system is in standby.
Twice as much ram takes twice as much power.
Historically, there was a requirement from MS that a PDA be able
to retain its memory for 72 hours after low battery shutoff.
Turns out that that takes a major portion of the battery cpapcity.
With 128MB it takes MOST of the battery capacity to save the contents
for 72 hours. Run time approaches zero.

Today's devices use persistant storage, so I suspect that requirement has been relaxed. I doubt my 64MB Wizard could last 72 hours on a fully charged battery with the phone radio on- I can't imagine many PPC phone users would leave the device's phone off for that long anyway.

If you have a program that needs more than 64MB of ram to run, you probably want a real laptop to run it.

Perhaps, but with WM5+ a 64MB device isn't really a 64MB device is it? After the phone radio software and OS load at boot, my "64MB" Wizard has about 25MB left to run software. Add in the wonderful memory leak "feature" of WM5 and WM6, and that 25 is lucky to be 12MB in 24-48 hours if I don't reboot (and that's even with closing all tasks with a task manager!)

128MB would allow me to run for days without rebooting.

So, it was decided in some backroom that 64MB of ram was optimal.
Vendors added non-volatile FLASH for program storage.

That was a WM5+ requirement, not a vendor decision.

It's much more
likely that you'll want lots of programs stored but not need much ram
to run them. I'd guess the internal flash is faster than a flash
card, but that's a guess.

I haven't noticed any difference there in practice. My WM2002 and 2003 devices were much snappier than my Wizard, using fast RAM as storage instead of flash-based memory.

Also, you get fewer problems when you
remove or change the flash card contents. The internal stuff is
always there.

True. I'd like a lot more RAM and storage memory!

Another advantage to this architecture is that you can turn the PDA
OFF and still retain program/data storage. When you turn it back ON,
it's like a soft reset. All the flash is still there.

That's the only advantage, and frankly, I'd rather have the speed of battery-powered RAM over slow flash given the choice, but others prefer the "safety" of flash memory.

I can turn my X51V off for weeks and it's still near 100% battery
capacity when I turn it back on. BIG advantage for those of us
who have more pda's than we could possibly use ;-)

For my older PDAs, I use scheduled backups for volitile data. I've never lost any data to a dead battery, and I've been using WinCE devices for nearly a decade.


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