I was going to do the same like as k1114 told.
But in the BIOS of my asus p8p67 le, was a selection of power saver/perfomance/stable in the "home screen" of BIOS. I turned it to perfomance and now cpu-z (+speccy) tell me that processors of my i7-2600 non K are running at 4.2ghz. How is this possible? The multiplier turned to 42? It should be max 38? i'm sure that my processor is the non k edition.
Temperature went a bit up, but not much. It's 40-55 Celsius.
This works fine, no problems.. In games my fps is much higher. Like in LoL it was usually 111fps @1920x1080, now it is 142fps.