I have my 6700k at 4.5, I just use the xtu and tweak the memory timing and multiplier. When I run adobe media encoder or matlab sim, both keep the CPU at 95-100%, for couple hours at the time, my CPU temp doesn't go over 70.. and voltage is around 1.21-1.29 ish.... I have an Itx case with 980ti which the gpu generates more heat than anything other components..