Windows XP only sees 2GB RAM w/ 4G installed

[OneWingedAngel42]

First, let me say that I've done significant googling on this topic, and fully understand the limitations of a 32-bit system only being able to address 4GB memory. I have read of others who install 4GB and Windows only sees 3 or 3.5GB or the like. I would be more than happy if that's what I was experiencing. Windows is reporting that I only have 2GB of physical memory, no matter what I do.

Here's the details: MSI P6N Diamond, used to be running 2x1GB Crucial Ballistix, just upgraded to 2x2GB Corsair XMS2. BIOS shows 4GB of physical memory, and I cannot find any BIOS options that would affect memory addressing.
Upon Windows XP Pro 32-bit booting, both the Task Manager and System Properties say that I have 2.00GB of physical memory only.
I've tried disabling DEP and PAE via boot.ini. and I've tried disabling paging (to possibly free up addressing space). I've also tried using the /3GB flag in boot.ini. Any combination of these has had absolutely no effect on what Windows reports as my total physical memory.

I have read that other hardware's memory (video/sound cards) can "eat" into the addressing space of Windows 32 bit. I have 2x MSI 8600GT each w/256MB RAM, and the onboard Creative soundcard with my motherboard. I find it hard to believe that this hardware could consume 2GB of addressing space.

As a counter-point, my system does seem to respond faster immediately after booting, and is snappier at switching tasks, so it could be benefiting from the additional RAM. I'm just trying to find out if it actually IS using more RAM, even if it's not using all 4GB. Is there some way I can find out if the RAM is being used, but Windows just isn't seeing it, or if there is some tweak I'm missing to make Windows see >2GB physical memory?

 

[JASTECH]

When I installed 4GB on my wife's Supermicro MB it only sees 3GB as that is the max XP 32bit can see. If you can go to XP 64bit it will see all 4GB.

Thanks, JASTECH

 

[Blain]

Reseat the DIMMs and see what happens.

 

[tcsenter]

Look in BIOS for memory remapping or memory hole, make sure its set to disabled.

 

[OneWingedAngel42]

Blain: Ok, I re-seated the RAM this morning, and swapped slots for fun, no change.

tcsenter: I dug through my BIOS again and wasn't able to find any memory-related settings aside from being able to manually set CAS, etc.
My mobo manual is here if anyone feels like double-checking me: http://www.msi.com/index.php?f...e&dno=5337&type=manual
I disabled Spread Spectrum for kicks, even though it shouldn't be related, and still no change.

I have friends with 4G RAM in WinXP Pro 32 bit who are seeing 2.75G+ in Windows, and according to them "it just worked". So frustrating...

 

[alcoholbob]

What about RAM set asside for VGA memory in the BIOS?

 

[OneWingedAngel42]

My motherboard does not have onboard VGA capabilites, but I checked anyway, and there are no BIOS options for allocating memory to VGA.

 

[lopri]

Can you post a cpu-z shot? Memory tab and motherboard tab. You can download cpu-z from cpuid.org.

Welcome to AnandTech Forums.

 

[OneWingedAngel42]

Sure thing. Nifty little program!
The screens are here:
http://www.sonic.net/jared/cpuz

 

[bwanaaa]

possibly,one of your ram slots got damaged. so even if you SWAP ram modules, one is not being read well. what happens when you boot with only one module in? do you get the same 2 gig reading no matter which slot you put the ram module into?

 

[coolVariable]

http://www.sonic.net/jared/cpuz/cpuz-memory.jpg

4GB?
What's the issue?

 

[OneWingedAngel42]

bwanaaa: I doubt that's the problem. I'm using the exact same slots that my old 2x1G sticks were in, and my bios shows 4G of RAM, so I don't think it's a physical problem. I think it's an OS problem if anything?

coolVariable: The problem is that Windows thinks I still have only 2G physical memory, see my OP. See this screen:
http://www.sonic.net/jared/cpuz/system-properties.jpg

 

[Nothinman]

I have read that other hardware's memory (video/sound cards) can "eat" into the addressing space of Windows 32 bit. I have 2x MSI 8600GT each w/256MB RAM, and the onboard Creative soundcard with my motherboard. I find it hard to believe that this hardware could consume 2GB of addressing space.

Whether you want to believe it or not that pretty much has to be the issue.

As a counter-point, my system does seem to respond faster immediately after booting, and is snappier at switching tasks, so it could be benefiting from the additional RAM. I'm just trying to find out if it actually IS using more RAM, even if it's not using all 4GB. Is there some way I can find out if the RAM is being used, but Windows just isn't seeing it, or if there is some tweak I'm missing to make Windows see >2GB physical memory?

If Windows says there's only 2G then it's only using 2G, the other 2G is sitting there idle.

When I installed 4GB on my wife's Supermicro MB it only sees 3GB as that is the max XP 32bit can see.

No, XP can "see" up to 4G but your hardware detracts from that number so the amount each installation usually sees sits somewhere in the 3-3.5G range depending on the hardware installed.

Look in BIOS for memory remapping or memory hole, make sure its set to disabled.

That will have no affect on 32-bit XP, enabling the BIOS memory remapping would only help competent 32-bit and 64-bit OSes see the memory.

 

[OneWingedAngel42]

Originally posted by: Nothinman

Whether you want to believe it or not that pretty much has to be the issue.

I'd find 2G of addressing space being used by hardware easier to believe if I could see it. There must be some utility or way of seeing how my 32 bit addressing space is being used. I am hoping someone here might know a way. I have a hard time just taking something like this on faith, especially since countless others get >2G physical memory in their XP 32 bit systems with bigger video cards, etc.

If Windows says there's only 2G then it's only using 2G, the other 2G is sitting there idle.

Exactly. I don't see why my system can't rank up to 2.75 or 3.5G of physical memory "seen" by Windows. That's what I'm trying to find the answer to. Is my system unique in some way, or am I doing it wrong?

No, XP can "see" up to 4G but your hardware detracts from that number so the amount each installation usually sees sits somewhere in the 3-3.5G range depending on the hardware installed.

And, as I said in my OP, if I saw anything above 2G of physical memory in Windows, I'd be happy, and move on with my life. I'm not, and I think I should, hence why I'm investigating.

I appreciate any information or advice that can help me understand this situation. A computer is a logical machine, there must be a logical answer to this.

 

[Nothinman]

I'd find 2G of addressing space being used by hardware easier to believe if I could see it. There must be some utility or way of seeing how my 32 bit addressing space is being used. I am hoping someone here might know a way. I have a hard time just taking something like this on faith, especially since countless others get >2G physical memory in their XP 32 bit systems with bigger video cards, etc.

There's nothing in XP that would make it cut you off at 2G unless it was a hardware issue. I've heard that some BIOSes let you change the memory alignment for the stolen chunks. Meaning that if it's set to 256M and 200M is 'lost' to hardware you'd still lose 256M because that's how the BIOS aligns it. So perhaps your BIOS is setup for some absurdly large amount like 512M or even 1G.

Exactly. I don't see why my system can't rank up to 2.75 or 3.5G of physical memory "seen" by Windows. That's what I'm trying to find the answer to. Is my system unique in some way, or am I doing it wrong?

I just meant that if your system feels faster it's just a placebo affect.

I appreciate any information or advice that can help me understand this situation. A computer is a logical machine, there must be a logical answer to this.

I'm sure that the logical answer is that it's a hardware issue and no amount of tweaking XP is going to help.

 

[OneWingedAngel42]

There's nothing in XP that would make it cut you off at 2G unless it was a hardware issue. I've heard that some BIOSes let you change the memory alignment for the stolen chunks. Meaning that if it's set to 256M and 200M is 'lost' to hardware you'd still lose 256M because that's how the BIOS aligns it. So perhaps your BIOS is setup for some absurdly large amount like 512M or even 1G.

I figured it would be a slim chance it was something in Windows, especially after trying disabling PAE/DEP and such. I've been over my BIOS time and time again and I can't find any setting in there relating to memory outside of overriding latencies and bus speeds. I've got an open ticket with MSI, just in case though.

I'm sure that the logical answer is that it's a hardware issue and no amount of tweaking XP is going to help.

That is it hardware related seems to be most likely, but I'd still like to know exactly what's doing it. Is it other PCI hardware taking up my addressing space? Is it a BIOS bug or incorrect setting? Is it something I can do something about or not? I'm just not the kind of person who can walk away from something that's not working as it should and say "Oh well". =)

 

[OneWingedAngel42]

Just a random update. I tried disabling my onboard NICs, firewire and sound card in the BIOS, and no change in Windows.

Also, for the people who do see >2G of RAM in Windows, did you need to add the /3GB flag to your boot.ini? I tried it and it didn't make any difference, and from how I understand it shouldn't change how much RAM Windows sees, but how Windows handles addressing its *virtual* memory per-application.

 

[tcsenter]

Originally posted by: Nothinman
That will have no affect on 32-bit XP, enabling the BIOS memory remapping would only help competent 32-bit and 64-bit OSes see the memory.

If memory remapping is enabled, it puts a larger chunk of RAM above 4GB where 32-bit Windows client and entry-level server SKUs can't see it. I said DISABLE memory remapping, not enable.

I've been over my BIOS time and time again and I can't find any setting in there relating to memory outside of overriding latencies and bus speeds. I've got an open ticket with MSI, just in case though.

Dude, did you check that you have the latest BIOS? Here are two change notes for the latest P6N Diamond BIOS v1.3:

- Update NVMM
- Fixed system report incorrect memory size when install 4G memory

You may want to run the MSI LiveUpdate utility, just to double check that is in fact the latest BIOS. MSI doesn't post the latest BIOS for certain models to the BIOS download pages and are only available through the LiveUpdate utility, but MSI doesn't make it easy to know which models because its not disclosed anywhere.

And no, do not use /3GB switch. This won't affect how much physical RAM the system can address or report. The per-process allocation of virtual address space is an entirely different matter.

 

[OneWingedAngel42]

Dude, did you check that you have the latest BIOS? Here are two change notes for the latest P6N Diamond BIOS v1.3

Oh yeah, I researched that a few weeks ago before getting the 4G of RAM. I'm running 1.3 now. I did the upgrade manually, as I've had bad luck with autoupgraders like LiveUpdate, but I'll give that a shot and make sure it says I'm clean.

And no, do not use /3GB switch. This won't affect how much physical RAM the system can address or report. The per-process allocation of virtual address space is an entirely different matter.

Yeah, that was my understanding of the /3GB switch, and that it is unrelated. Funny, because MSI tried to tell me it was an OS problem and referred me to a MS KB article that talked about PAE and /3GB... Yay.

 

[tcsenter]

Originally posted by: coolVariable
4GB? What's the issue?

The memory tab of CPU-Z just regurgitates whatever is defined by the SPD on the memory module. If the SPD were incorrectly programmed as 2GB on a module that is only 512MB, CPU-Z would report it as 2GB. In fact, SPD has its own pins and bus that are independent from the rest of the module. As long as that SPD is working, CPU-Z will report whatever is in it even if the rest of the module is complete non-functioning. In that way, its a bit useless.

Originally posted by: OneWingedAngel42
Oh yeah, I researched that a few weeks ago before getting the 4G of RAM. I'm running 1.3 now. I did the upgrade manually, as I've had bad luck with autoupgraders like LiveUpdate, but I'll give that a shot and make sure it says I'm clean.

You don't need to actually proceed with the BIOS update via LiveUpdate. You can use it just to confirm that v1.3 is indeed the latest BIOS available from MSI.

I have seen peculiar cases like this before. Have you tested each module by itself? Try shutting down, removing one of the 8600 GTs, clear/reset the CMOS. Boot and restore your custom BIOS settings, Save and Exit, then boot into Windows and see if anything 'shakes up', in a manner of speaking. You can install the other 8600 GT again later.

 

[alcoholbob]

Edit.

 

[Nothinman]

If memory remapping is enabled, it puts a larger chunk of RAM above 4GB where 32-bit Windows client and entry-level server SKUs can't see it. I said DISABLE memory remapping, not enable.

I realize what you said and what remapping does. The memory lost to hardware is going to be the same whether or not that lost memory is remapped above 4G so changing that setting should have no affect on XP.

 

[OneWingedAngel42]

Okay, so progress has been made!
I opened my system up, reset the CMOS and removed one of my two video cards (http://msicomputer.com/product...=NX8600GTS-T2D256E_OC). Windows boots up, and reports 3G of physical memory!
However, upon re-insertion of the second video card, it goes back down to 2G of physical memory reported.

So now I have a culprit, but losing 1G of address space to one 256M video card doesn't make any sense. Especially since with one video card, I'm down to 3G (from the 3.5G that everyone reports is the best that Win32 can see).

So, does anyone have any idea why I'd be losing 1G of addressable space to a 256M video card? Or who I should talk to about it? MSI? nVidia?

 

[tcsenter]

Originally posted by: Nothinman
I realize what you said and what remapping does. The memory lost to hardware is going to be the same whether or not that lost memory is remapped above 4G so changing that setting should have no affect on XP.

It depends on the remapping implementation and granularity either chosen by the BIOS designer or permitted by the chipset. There have been numerous cases where remapping enabled resulted in a larger memory hole under 32-bit OS (sans "real" working PAE) than with remapping disabled, and not by just a few dozen MB. Now I don't know whether this was just a case of early BIOS remapping or chipset programming decisions not being very smart due to inexperience with remapping, or resulted from actual limitations in the first couple generations of chipsets that supported over 4GB memory addressing, but I'm not imagining it.

 

[Nothinman]

So, does anyone have any idea why I'd be losing 1G of addressable space to a 256M video card? Or who I should talk to about it? MSI? nVidia?

The BIOS, like I said the 'lost' memory is aligned to certain values which are rounded up to regardless of the real amount of address space required.