XP 32bit only seeing just over half the RAM

[hunterjwizzard]

Hey folks, got a weird problem: I just did a fresh install of Windows XP 32 bit Corporate Edition, SP3 preloaded. The PC has two 2gb sticks of RAM and the BIOS reports all 4GBs, but Windows is only seeing 2.25gb. The previous XP 32 bit install on the same system reported all 4GBs. I got no clue what's up.

Any ideas?

 

[Unknown_K]

32 bit OS can only use 3.25 to 3.5GB because the rest is reserved for address space mapping. If you have multiple GPUs or you are using a CPU with video you get less.

 

[hunterjwizzard]

Well you may notice 3.5 is still quite different from 2.25. It should be seeing at least 3.5. I was NOT using a 64 bit version of the operating system before and it was reporting 4.0gb. Either way, it should be reporting more than 2.25.

 

[krebizfan]

You could try the 3GB switch in boot.ini. That may not work out well if you have big memory video cards wanting to eat up a lot of address space.

Maybe telling us a bit about the motherboard would help determine if there was some other problem.

 

[hunterjwizzard]

I have big memory video cards bit, again, the exact same computer with the exact same graphics card(only change is a fresh OS install) displayed 4gb before being formatted. So I don't think its the graphics cards.

 

[Eudimorphodon]

There's a PAE patch for Windows XP. (Google it.) Maybe you had that installed and didn't know/forgot. There are a lot of known gotchyas with enabling this, but if it worked before, *shrug*, you can try that.

 

[Quagmire]

FWIW: My XP 32 Enterprise sees 3.49GB RAM of 4 GB RAM installed. The video is a Radeon 5800 8GB that works okay with most games. I used this card because it jumped to the top of pile when I put this box together. I recently found others but see no need right now to fool with the system.

 

[Zare]

Was your previous install SP3 too? SP3 is almost like another version of the OS considering how many system components have been updated.
I think there is a limit value somewhere in the registry, accessible with msconfig I think in boot tab. Maybe the installation was provisioned with some value.

I know wrong number irks you but it is impossible to max out 32-bit Windows without heavy multitasking since process is still limited to 2 GB.

 

[HaHa I]

I had xp32 bit on a x79 systems with dual titian X's a 12gb card and I still had accesses to 3.5gb. Does your system have an on board video card that you are not using ? if so disable it in the bios. the 3gb ini switch is worth trying but that's more to change how much ram per app can use. you can try PAE mode too but if you have more them 4gb of ram even just a smidge EAX will not work. there was a 3rd party patch to fix that on xp64 bit that that was lost to time.

 

[Quagmire]

Was your previous install SP3 too? SP3 is almost like another version of the OS considering how many system components have been updated.
I think there is a limit value somewhere in the registry, accessible with msconfig I think in boot tab. Maybe the installation was provisioned with some value.

I know wrong number irks you but it is impossible to max out 32-bit Windows without heavy multitasking since process is still limited to 2 GB.

I have SP3 installed as well as the unofficial SP4

 

[hunterjwizzard]

Does your system have an on board video card that you are not using ?

There is fact no onboard video. This was a really fancy enthusiast-grade motherboard. The onboard sound is knackered, though.

I know wrong number irks you but it is impossible to max out 32-bit Windows without heavy multitasking since process is still limited to 2 GB.

What bothers me more(And I'm not sure if this is true) is that it makes me think its only "using" 1 stick, and that's going to hurt performance.

So eventually I gave up and swapped the 4gb kit for a 2gb kit. I'm also going to invest in some DDR2-1066 sooner or later. So its "working" for now on that.

 

[bakemono]

if you run System Information Viewer, and go to system / PCI BARs you can see a breakdown of address space usage. That might give a hint as to why you only have 2.25GB instead of the usual 3 ~ 3.5GB