I set the cache ratio to be the same as the clock, maybe .1 less. It normally requires less voltage also, mine takes .05 less.
I'm running my 4670k at 1.25V at 4.5Ghz, cache is also 4.5Ghz with a voltage of 1.2.
Voltage on Adaptive.
Max temps around 85C with a 212 evo, using Intel Extreme test