Well, these benchmarks don't tell you the whole story. The 5775c runs at a quite low speed, 3.7GHz. While it doesn't clock very high, 4.2GHz is a decent relative overclock (4.55GHz for the 6700k) and on top of that there is the EDRAM going up to 2GHz.
Also, all DDR3 platforms use ram at 1866MHz...