I recently decided to add 512MB RAM to the existing 128MB RAM that came with my computer. I carefully looked up what my mobo can accept, both slots can accept 512MB RAM, PC100 or PC133. I installed my new RAM and found that the computer was only recognizing 300 some MB. I tried taking the old one out and it only recognized 200 some MB. Finally, I took the new one out and put the only the old one back and it only recognizes 96MB out of the 128MB. Leading me to believe there is something wrong with the mobo, not the RAM. Ideas anybody??? I just read some similar posts and some explanations are that I'm using high or ultra high density memory, that there was electrostatic damage, or that there are bugs in the bios. The first two explanations don't explain why my original memory wasn't recognized. Could an error in the bios cause what I'm seeing? And how would I fix that?

Do you have any integrated video? Maybe it's using up some of the RAM.

My video card is integrated onto my motherboard, if that's what you mean, and the spec sheet says "Graphics accelerator with 32MB frame buffer embedded in North bridge". 32MB is exactly what I'm missing from the first memory stick! Yay! That might be the "problem" which isn't really a problem. Thanks! BTW, I've added up numbers more carefully and I am getting 96MB out of the first stick and 256MB out of the second. I suspect the second is high density, but I don't know how to tell for sure. I'm off to look at old threads again...

One clue to high density RAM is the number of chips on the module...generally, high density is single sided (8 chips) & low density is double sided (16 chips). Your mobo specs must state that it accepts 512mb in EACH slot for high density RAM to work...if you have 3 DIMM slots, your max capacity must be listed as 1.5gb. http://www.icentral.com/html/1stchoicememory/memoryfaq.html

Thanks Jam. Both DIMM slots (I only have 2) do accept 512MB for a max of 1GB. My old 128MB has 8 chips on one side. What's weird is that the new memory stick is enclosed, so I can't see the memory chips. I'm guessing it's high density, but it seems my mobo should accept high density, so I don't know what gives. How do you check if your bios has a limit on the memory it can detect? I got into my bios setup utility and I didn't see any options like that.

Enclosed PC133? I've never seen it that way...what brand? Your BIOS doesn't limit your RAM recognition, your chipset does...what mobo/chipset do you have? From what you've said though, it seems it should detect high density RAM

I don't know the brand, it doesn't say anything on it besides the specs. I got it on ebay and it came in a plain box. The seller has abandoned his ebay identity, so I can't even ask him! Maybe this is really the root of my problem... The mobo is Aristo M754LMR and the chipset is ALi M1631 ALADDiN TNT2.