Another site about memory -

Post - Actually, I have 2 128's. So I have 256. ANd I can't get 2700 or 3100, I already know that. I've read up a little and asked other people, but my dad told me I couldn't mix sizes, so I told him and he learned something new too.

Reply - Another surprise - yes you can. You can overspec memory with no trouble. You can mix speeds too.

SysOpt Forums - Question about memory upgrading