Hi, I'm in the process of building a new PC. AMD phenom II 940 black edition paired with a ASUS M3A78-T. From some of the review i have read, the phenom has the potential for overclocking. My question is which spec of DDR2 do i really need 667, 800, 1066?? I may overclock in the future, but since its not built yet, I don't know if i'll actually need to overclock.