What are the effects of combining two different types of RAM. I currently have 1gb (512x2), and am looking to buy 2gb (1024x2). My current configuration of 1gb has timing of 2-2-2-6, and the 2gb has timing of 4-4-4-12. If I had all these combined (3gb), would it be better or worse than the 2gb dual channel? I'm not too sure about how timing and dual channel works.