on my mobo i have three banks to put ram into. i currently have two DRR400 sticks of 512mb memery. i was wondering if it was possible to add an additional gig of memery. 512+512+1024=2gigs or would it be better to buy two 1gig sticks. my chief concern here is cost, but system speed/stabilty is also important. any help would be appreciated

The RAM chips your system supports do not need to be matched for size
(256, 512, 1024). They do need to be matched for speed (PC133, PC2100
or PC2700). Mismatching the speed will cause the system to drop down
to the lower speed setting and use both chips at this lower speed.
Sometimes this can cause incompatibilities and system errors. You
will want to ensure the chips are the same speed.

gotcha thanks