I have an i5-2500k, but not OCed. I was playing Anno 2070 today and my 212 evo seemed to keep fluctuating alot. One moment it would be going full blast and be really loud, while the next it would calm down and get quite (not idle quite just more so then before). Is this normal or is there something I can do that would help it stay constant? I know I can make it stay a current rpm through the motherboard controls but I don't much like the idea due to the potential of me setting it wrong..