More than 4 GB of ram

[k_mohsen]

Hi
Everyone knows windows xp pro 32bit only support 4 GB of ram.
(And windows don’t use 4 GB; you can use only 3.4 GB of ram.)
Is Microsoft release any update for windows xp pro 32bit to support (and use) more than 4 GB?
Notice: win xp pro 64bit support 16 GB of ram but some programs don’t work prefect with 64bit os and someone have to use windows xp pro 32bit and need more than 4gb.

I can’t find this update.
Thanks 

[Dias de verano]

There will never be any "update" for any 32 bit OS to use more than 4 GB of RAM, because of the simple fact that 2^32 bytes=4 GB. Although it may be possible for individual programs to use more than 2 GB if Physical Address Extensions are enabled, this can be tricky and not much advantage gained, in particular this is a bad idea with Server 2003.

[k_mohsen]

There will never be any "update" for any 32 bit OS to use more than 4 GB of RAM, because of the simple fact that 2^32 bytes=4 GB.

more info please.
why 2^32=4 GB?
in calculating it is true , but i never see this in science of computer.

thanks

[Dias de verano]

In a "32 bit" OS, the addressing scheme uses 32 bits to represent byte addresses. The highest byte address that can be represented in 32 bits is 1111111111111111111111111111111 binary or FFFFFFFF hex or 2^32 or 4,294,967,296.

i never see this in science of computer.

Then you have not looked very hard! 

[Calum]

in particular this is a bad idea with Server 2003.

Why's that?  I've never come across this before.

k_mohsen, what are you using that needs more than 4GB of RAM anyway?

[Dias de verano]

in particular this is a bad idea with Server 2003.

Why's that?  I've never come across this before.

I should have made it clear it was the /3GB switch I was referring to - with a 32 bit OS and 4 GB of RAM,  the switch makes 3 GB of addresses and thus memory available to user mode applications by taking away 1 GB from kernel mode. There are potential problems with hardware drivers not loading because there aren’t enough resources available to kernel mode. You can limit this impact by disabling unused hardware (i.e. disable USB, Firewire, Serial Ports, etc in the BIOS and remove sound cards and other hardware that isn’t needed) and by limiting the functionality of other hardware (i.e. don’t use high resolutions and high color depth for video when you don’t need it). Server 2003 exhibits particularly degraded performance if the kernel is starved of resurces, I have read.


http://blogs.msdn.com/oldnewthing/archive/2004/08/05/208908.aspx
 

[k_mohsen]

k_mohsen, what are you using that needs more than 4GB of RAM anyway?

i don't need this , my pc have 1 GB .
but i want to know this. i see this before in some article and never think about it , that why only 4GB for 32bit os .

thanks to all

[Calum]

OK, thanks Dias, was just curious - I thought you meant enabling PAE was a bad idea, which surprised me as I always run with it enabled..  I agree however, the /3GB switch doesn't usually help anyway, and I have heard of it causing some problems.  I didn't realise it could cause issues as serious as those you describe though.
Thanks for the clarification, you learn something new every day I guess.