if u changed ur fans from a none pwm header to a pwm header it could be that the pwm is running ur fans at a lower speed.
pwm headers are 4 pins so if u plug ur fans into that u can use software to control there speed but a 3pin header will just run max.
im using a 4790k on a z97x soc with a h100i.
i have tried a few oc over a few years 4.8 ghz at 1.3 and 1.35v
and 4.9 ghz at 1.35v
after i turn the pc on i have about 10 mins till the pc will just restart on bsod no freezes just restarts and then opens bios saying to reset to default settings...