I currently have a pair of 64MB sticks (that originally came with computer), and a pair of 256MB sticks (that I purchased later, the guy at the store just gave them to me and they worked).
I'm planning on replacing the 64MB's with another pair 256's.
I don't know if it matters but, CPU-Z lists the 64's as:
PC600-53 (300 mhz)
and the 256's as:
PC714 (357 mhz)
I know very little about this stuff so if I left out some necessary piece of information please tell me, and thanks in advance for any help.