First, he experimented with lapping an E6700 heatspreader. Decided to lap my E6700 B1 IHS and it's the best lap job i've done so far compared to what I did on E6600s. E6600s didn't gain any clocks or temp reductions when lapped as the IHS was already flat. But E6700 cpu when i started to lap only the 4 corners went to copper for a while so the IHS was definitely concave!