At first my temps were <70 at stock volts with 4 ghz, and hitting 99-100 at 4.5 ghz

I fixed it by adding a third high CFM at the top case exhaust, but as an intake fan blowing onto the CPU area, and two more of the same fans were already set up as push pull exhausts on the h2o 620s radiator.

This dropped my temps to <60 at 4 ghz, and <90 at 4.5 ghz on a cheap cooler

The fans are silent too - 1500 RPM Xigmatek fans hat push 63 cfm

I should buy another two of them for my case intake fans.