Yeh tried re mounting to begin with, then changed to stock then new cooler, all 3 times confirmed it was mounted correctly. Even tried less or more paste to see if it made any dif. - none to be had
I have tried it on power save normal and the top power settings on the asus bios front screen changes between 1-1.3v doesnt make a dif.
I had used prime once, but upon reading about issues that others had i also removed, easiest one i tested was excel i was working on, vlookup ran, temp went sky high, then back to idle temp.
Happened also in Furmark, and gaming.
Note also, i have it in a Fractal Design Define R4 with 2 inlet fans and 1 exhaust fan at the back, along with the dual rad.