We overclocked the chip by raising the voltage from around 1.1V to 1.35V in the BIOS. The next step was to increase the multiplier until the chip failed to complete the six-minute-long wPrime test, indicating basic stability problems. Learning lessons from the original Core i7-3770K review, we had to swap the small-ish reference heatsink for a Corsair A70 cooler armed with two 120mm fans, as the Ivy Bridge chip has a tendency to become very warm when over-volted. Indeed, it would almost instantly throttle when run with the stock 'sink, at 1.35V and 4.6GHz.
Anyway, we managed a stable speed of 4.7GHz (47x100MHz BCLK) that would complete all of our benchmarks.
The upgraded cooler kept the chip at around 76°C when under load. The temperature is higher than we'd like, assuming it's being reported correctly, and the spiralling temps for Ivy Bridge chips may be a cause for concern for SIs whose best-selling systems - currently based on Sandy Bridge - tend to be overclocked to 4.5GHz-plus.
HEXUS PiFast is a single-threaded application that loves IPC and frequency - the two features that an overclocked Core i5-3570K has in spades.
The four-core, four-threaded 3570K just about beats out a stock-clocked 3770K in the all-core CineBench test. Remember that the range-topper can process eight threads at one time, thanks to hyper-threading support.