The guys over at OCLab.RU were able to get hands on an Intel Haswell engineering sample and have run a few benchmarks of the chip comparing it against the Core i7-3770K in a clock-to-clock testing session.

First Intel Haswell Benchmark Tests Appear

The Intel Haswell engineering sample had the B0 stepping and was notably ran on an Z87 chipset motherboard. The site didn't mention the brand or model the used for the test. Since the Intel Haswell ES chip was clocked at 2.8 GHz, the team had to downclock the Core i7-3770K for a fair benchmark comparison. Following is the testbed used: