I don't think that w7-index is something accurate and trusty for the measurement of CPU performance, CB 11.5 and vPrime are much better.

MY 1600MHZ CL8 RAM scores 7.9, but both my w3520 @4.51GHz and 2 x X5650 @3.8GHz (and i tries up to 4Ghz) never could hit that, they are always at 7.8.