I just built a new PC and I am running an Intel DX48BT2 board with 2x1GB Corsair XMS3 DDR3 1600 PC 12800. I am in need of some cash and right now I can't afford more DDR3 so is it possible to stick in 2x1GB Corsair XMS2 DDR2 800 PC 6400 from my old box? Will that slow down the DDR3, or not be compatible at all? Please let me know.