Right now im using a i5 4670k @4.2GHz @1.19v with an Artic Freezer i11 cpu cooler. When i game it usually maxes out at 45-50c. I wanted to see if removing my heatsink fan would reduce pc noise but im unsure whats a safe clock speed/voltage for a passively cooled cpu? im not planning do this forever just wanna test it for a few hours or so.