At 5,666 GHz, the Core i7-3820 is tuned

GUN'G'STAR, a member of the TeamRussia team, achieved this "evil result" with the Intel Core i7-3820 processor.

To reach the 5,665.99 MHz clock, take a 131,74 MHz BCLK clock, multiply it by 43, turn off Hyper-Threading technology and two processing cores, and then pour the whole thing around your neck with a good dose of liquid nitrogen - the latter information does not revealed from the official announcement, but can be rightly assumed. The resulting Core i7-3820 processor comes with an ASUS Rampage 4 Extreme motherboard and Geil four-channel memory. The latter plays a side role in this story, so GUN'G'STAR also thoroughly retracted the clock and timing of the 1600 MHz modules. The processor operated at an operating voltage of 1,6 volts during the overclocking. The result verified by the CPU-Z can be seen below.

Source: techpowerup.com