Windows Vista reads as 3 GIG only

[nightthief]

Well, my new pc will be a custom build with a new pci-e/x slot on a newer mobo that most likely will be 64bit ready. I only regret buying a 32bit Vista when I should have gotten the 64bit now. Oh well, you learn from experience. Thank you.

See http://www.microsoft.com/windowsvista/1033...ia/default.mspx to order the alternate media at a significantly reduced cost ($10/per disc).

[Access Denied]

Sweet! Thanks alot!

[cluberti]

Note that the answer to this question has been stickied here for future reference.

[Thunderbolt 2864]

Ok guys, thanks for the distinct explanation. I don't get it though, I have a 32 bit Windows Server 2003 on my computer and it can see all 4 GIGS. Why is that, if other 32 bit OS are limited?

[cluberti]

Ok guys, thanks for the distinct explanation. I don't get it though, I have a 32 bit Windows Server 2003 on my computer and it can see all 4 GIGS. Why is that, if other 32 bit OS are limited?

Is it server 2003 Standard or Enterprise edition, and is the processor x64 capable? If so, that's because /PAE is enabled by default in this scenario, and /PAE allows addressing of memory above the 4GB boundary. Unless you really want to research the Intel documentation as to how this memory is reserved (and bore yourself to death), I'll save you the trouble and give you a "high-level" synopsis - the BIOS "moves" the 4GB boundary down to 3GB or 3.5GB (or whatever) so that it can reserve the memory above it for devices. Since /PAE allows a machine running a server-class Windows OS (or an x64 OS) to see "above" the new "boundary" the BIOS artificially creates, server 2003 and x64 OSes can then see this memory the BIOS has reserved, and can actually use most of it if the BIOS doesn't lock it. Since client OSes (non x64) cannot see above 4GB with or without /PAE enabled, they'll still only see 3 or 3.5GB (or whatever) when /PAE is enabled, whereas server OSes can and will see above the artificial 4GB boundary when /PAE is enabled.

[jcarle]

So what use is it to have PAE enabled on XP?

[nightthief]

So what use is it to have PAE enabled on XP?

Please read: http://www.microsoft.com/whdc/system/platf...PAE/pae_os.mspx

[jcarle]

So what use is it to have PAE enabled on XP?

Please read: http://www.microsoft.com/whdc/system/platf...PAE/pae_os.mspx

Windows XP SP2 and later - AWE API and 4 GB of physical address space ... so again, what's the use of PAE?

[Mr Snrub]

Windows XP SP2 and later - AWE API and 4 GB of physical address space ... so again, what's the use of PAE?

"Although support for PAE memory is typically associated with support for more than 4 GB of RAM, PAE can be enabled on Windows XP SP2, Windows Server 2003, and later 32-bit versions of Windows to support hardware-enforced Data Execution Prevention (DEP)."

Also, as the BIOS can be moving the addressable memory just above the 32-bit addressable barrier, you need the PAE kernel to be able to address above this address as it's effectively beyond 4GB, even if only 3-4GB is installed.