I've read a number of postings but am still going to post this question because I want to make sure I have this absolutely right. From what I understand a system memory involves 2 memory sticks, not just 1 . For instance, my currect system (A Dell Dimension 3000) is currently running with 512 MB of system RAM. If my math is correct, that means I currently have two 256 MB sticks. And, If I'm going to increase my systems RAM from 512 to 1024, then I'll want to buy 2 512 MB sticks, because if I buy just a 1024 stick and use it to replace one 512 MB stick, the computer will still run at 512 MB. Does this sound right? I'm currently in the process of some upgrades (added DVD/CD Drive, added a GE Force 6200 OC graphics chip) to play Oblivion and believe the final upgrade should be a memory upgrade. So, am on the path or still floundering in the dark re: memory? Thanks for the help.