I'm in the middle of the usual research before making a new system, and I'm trying to really pay attention to the upgradeability of the system. Right now I would prefer getting my motherboard and putting 2 or 4 gigs of ddr2 800 in it, but I also want to be able to use ddr3 down the road. Do these use the same interface (aka could I get a motherboard that supported both of them) or will I have to buy a new mobo when I want to switch to ddr3?