Hello,

I recently upgraded my crummy value RAM to 4GB of DDR2 800 Mushkin 4-5-4-11 and only 2.43 GB are showing up. Now, I understand the limitations of a 32-bit operating system with regards to addressing more than 4GB of total system memory, but I'd think that ~3GB would show up. My system specs are as follows: Asus P5B Deluxe/ E6600 @ 3Ghz/ 4GB Mushkin DDR2 800 4-5-4-11 @667Mhz/ 7950GX2. This isn't a huge deal as I only rarely get to 100% RAM usage, but it is frustrating nonetheless. Any help/advice you might be able to provide would be very welcome.

Thank you,

X

Have you scanned for errors in the memory?
I'd recommend putting them in two at a time to see what happens. Or run memtest - but you need to boot that from a CD or floppy - or some versions of ubuntu come with it on the CD (I know kubuntu does anyway).

Try reseating the memory.
How much is shown in the bios?

It's probably because the 7950 GX2 has 1gb of ram which is hogging a lot of the addressing space.

Windows XP 32 bit version will accept up to 4GB of memory. However Windows will reserve the address space 3.5GB to 4GB to hardware devices. If these devices need more memory, Windows will allocate more of it to accommodate it. It is rare but not uncommon to see a system with 4GB of memory installed and only 2.75GB that is usable. Another note PCI-E 16x usually will gobble up 256MB of the address space. So if you have an SLI configuration, the 2 PCI-E 16x cards will chew up 512MB on top of the other devices that need the address space. It is possible to tweak the BIOS to reduce the amount of memory these devices use but often the result is negligible.

In The BIOS under northbridge Change the memory remap. When you change it you will see 3 Gig. This is a chipset limitation.

1Haplo

that gx2 has 1gb of memory on it right? That's memory that's getting addressing priority over the standard system memory.

You're fine. The GX2 acts like two cards in using up memory.

Bingo!

Yah alot of people don't really understand the memory addressing, which I understand because not until recently has it been an issue. The only reason I understand it is because i'm a csc major, and you'll learn/be forced to learn about memory addressing when learning C.

Just to verify that all 1GB of gfx RAM is being mapped into the CPU's address space, could the OP give us a copy/paste of his memory map (can be found with msinfo32)?

Thanks for all the replies. I tried enabling memory remap in my BIOS and that dropped my RAM down to 2GB. So, what am I missing? 4GB 32 bit OS limit minus 1GB for my video card = 3GB, right?

Below is the what I think is what you were looking for, dengamle. If not, let me know and i'll look again.

0x9C000000-0xFFFFFFFF PCI bus OK
0xF6500000-0xFE7FFFFF Intel(R) P965/G965 PCI Express Root Port - 29A1 OK
0xF6500000-0xFE7FFFFF PCI standard PCI-to-PCI bridge OK
0xF6500000-0xFE7FFFFF PCI standard PCI-to-PCI bridge OK
0x9FE00000-0xDFDFFFFF Intel(R) P965/G965 PCI Express Root Port - 29A1 OK
0x9FE00000-0xDFDFFFFF PCI standard PCI-to-PCI bridge OK
0x9FE00000-0xDFDFFFFF PCI standard PCI-to-PCI bridge OK
0xFE7FC000-0xFE7FFFFF PCI standard PCI-to-PCI bridge OK
0xF9000000-0xF9FFFFFF NVIDIA GeForce 7950 GX2 OK
0xA0000000-0xAFFFFFFF NVIDIA GeForce 7950 GX2 OK
0xF8000000-0xF8FFFFFF NVIDIA GeForce 7950 GX2 OK
0xFA600000-0xFE6FFFFF PCI standard PCI-to-PCI bridge OK
0xBFE00000-0xDFDFFFFF PCI standard PCI-to-PCI bridge OK
0xFD000000-0xFDFFFFFF NVIDIA GeForce 7950 GX2 OK
0xC0000000-0xCFFFFFFF NVIDIA GeForce 7950 GX2 OK
0xFC000000-0xFCFFFFFF NVIDIA GeForce 7950 GX2 OK
0xFEBFFC00-0xFEBFFFFF Intel(R) ICH8 Family USB2 Enhanced Host Controller - 283A OK
0xFEBF8000-0xFEBFBFFF Microsoft UAA Bus Driver for High Definition Audio OK
0xDFE00000-0xDFEFFFFF Intel(R) ICH8 Family PCI Express Root Port 1 - 283F OK
0xFE900000-0xFE9FFFFF Intel(R) ICH8 Family PCI Express Root Port 5 - 2847 OK
0xFE9FE000-0xFE9FFFFF JMicron JMB36X Controller OK
0xFE800000-0xFE8FFFFF Intel(R) ICH8 Family PCI Express Root Port 6 - 2849 OK
0xFE8FC000-0xFE8FFFFF Generic Marvell Yukon Chipset based Ethernet Controller OK
0xFEBFF800-0xFEBFFBFF Intel(R) ICH8 Family USB2 Enhanced Host Controller - 2836 OK
0xFEAFF800-0xFEAFFFFF Texas Instruments OHCI Compliant IEEE 1394 Host Controller OK
0xFEAF8000-0xFEAFBFFF Texas Instruments OHCI Compliant IEEE 1394 Host Controller OK
0xFEAF4000-0xFEAF7FFF Marvell Yukon 88E8001/8003/8010 PCI Gigabit Ethernet Controller #2 OK
0xFFAFE000-0xFFB0CBFF Motherboard resources OK
0xFFB00000-0xFFBFFFFF Motherboard resources OK
0xFED1C000-0xFED1FFFF Motherboard resources OK
0xFED20000-0xFED8FFFF Motherboard resources OK
0xFFF00000-0xFFFFFFFE Motherboard resources OK
0xFEBFE000-0xFEBFEC00 Motherboard resources OK
0xFED00000-0xFED003FF High precision event timer OK
0xFEC00000-0xFEC00FFF Motherboard resources OK
0xFEE00000-0xFEE00FFF Motherboard resources OK
0xFED14000-0xFED19FFF System board OK
0xE0000000-0xEFFFFFFF Motherboard resources OK
0x0000-0x9FFFF System board OK
0xA0000-0xBFFFF PCI bus OK
0xA0000-0xBFFFF Intel(R) P965/G965 PCI Express Root Port - 29A1 OK
0xA0000-0xBFFFF PCI standard PCI-to-PCI bridge OK
0xA0000-0xBFFFF PCI standard PCI-to-PCI bridge OK
0xA0000-0xBFFFF NVIDIA GeForce 7950 GX2 OK
0xC0000-0xCFFFF System board OK
0xD0000-0xDFFFF PCI bus OK
0xE0000-0xFFFFF System board OK
0x100000-0x9BFFFFFF System board OK

You'll probably be able to answer your own question after looking at the memory addressing you just posted a little more. If not, Basically everything you see there is using up memory. If you want to calculate what each entry is using up, take the address range, subtract the first number from the second, then convert it from hex to decimal. The numbers, I believe, should be in bytes. I can't remember why, you would think it would be in bits. (Correct me if i'm wrong here, I think I might be confusing this with C automatically casting into bytes or something, which is what i'm pulling this logic from). Also, when doing the calculations, you can chop off the 0x part, that just letting you know it's a memory address.

Correction: 4GB total address space, less 1GB for Video Ram, Less the address allocation for all the devices/ports besides your Video card which are listed in your post. Here, I deleted the video card related items from your list - Below is a list of the remaining items which are also consuming address space: