Overclocked, the 7700K reached a stable 4.9GHz using 1.33 volts. Under full load it reached 95 degrees!
That overclock boosted the Cinebench R15 score by 9% for a multi-threaded score of 1083 pts.
The Core i5-7600K also hit 4.9GHz using 1.33 volts and again it was stable at this frequency.
This overclock allowed for a rather impressive 16% boost in score when testing with Cinebench R15.