I'm going off CPU temp, I tried it @ 4.0 GHZ and it shot up to mid 50's over 60 in load / crashed when stress tested. It's knowing when to stop... Bet if I had a better fan etc, I could get it higher no probs.
I use it for music production, so my DAW is using all six cores for compressors, instruments etc.
Seems to be great at 3.8GHZ.
In AMD overdrive it says core temp is 24C.
BTW do you leave the side of the case off? I always do with a stock fan.