RAM issues

[Bluefox815]

In my computer I have 2x 128 mb SDRAM sticks. However, one of them only reads as 90 mb, which I would think is the stick's error. So I bought a new 128 mb stick (SDRAM) and swapped it out, but my total ram still read 224 (128 + 90). I tried all possible combinations and still nothing better. So I removed all SDRAM sticks and tried inserting a 256 mb DDR stick (I have 2 slots DDR, 2 slots SDRAM). When I start up the computer, my total RAM reads 160 mb! I know for a fact that the 256 stick works. So my question is, which is causing the problem, my motherboard/cpu/other hardware, or my Windows XP os?

[PeejAvery]

Do you have a shared memory video card? This would account for the borrowing of RAM.

[Bluefox815]

I have a video card, but it has it's own memory, and even before I got it the problem was present. My video card before was the integrated S3 MS card, which is common and doesn't cause loss of RAM from what I've seen. I had a lot of hardware swapping with the sound and video cards, and the RAM, but no change. I actually was having sound problems which were obviously because of my OS, so I reinstalled windows with the disc I had and had sound, but this problem happened.

I think a good way to test this is to get a live linux CD (I was thinking of trying Knoppix anyway) and see how it reads RAM. I never used linux before though and heard that the interface is somewhat less easy than windows, so could someone tell me how I see how much RAM I have according to the system? I don't want to backup my files again and don't have the disc anymore, so I'm hoping that I can learn how to use linux and dual boot my windows that I have now, assuming windows is the issue here.

[PeejAvery]

Well, what does the BIOS say. If Windows is the culprit, then the BIOS will read correctly. If the BIOS too has a miscalculation, then you know it isn't Windows.

[S_M_A]

If you just want to do a quick check with linux without installing anything some (most?) distributions are available in a bootable CD version like this http://librenix.com/?inode=5378

[Bluefox815]

Sorry for the delayed reply, but I just recently was able to find my ram size according to my BIOS. The BIOS reads my ram as 229376 kilobytes which is exactly 224 megabytes (what Windows reads my RAM as), so my problem is not due to Windows. Does anyone have a suggestion of how to fix this misread issue without buying a new computer? (See first post for details)

[PeejAvery]

256 - 224 = 32. As I mentioned earlier, the RAM is being borrowed as virtual memory. Check your AGP aperture inside the BIOS. I would guess it is set to 32MB.

[Bluefox815]

Ok, that makes sense. However, why is it that a 265 mb DDR stick reads as 160 mb?

[PeejAvery]

Same thing...256 - 160 = 96. Although not a direct bit number, it is still a commonly achieved addition of bit numbers (eg. 64 + 32).

[Bluefox815]

Screwy computer. Thank you PeejAvery, you have been very helpful.