You dont start to see benifit from ddr3 over ddr2 i believe until you get to around 1700 mgz, there is not a ton of difference between the ddr2 and ddr3, but when you start hitting 1800 + you get some decent benifit.

The big thing to me is ddr2 has reached its max, ddr3 has no way come close to its max yet, there up to ddr3 2133 mgz and climbing. I7 takes full advantage of ddr3, the p45 chipset and ddr3 are just not a good match, you need a x48, 790i chipset, or 17. Bob your better off getting a x48, 790i, i7 if your going ddr3, or use the ud3p for ddr2, hope that helps you.