At 1.40 V vCore creates my 1090T readily 3.8GHz - where I have turned the Core Boost and only'm running C & Q.
Amazingly, despite supposedly stable 4.0 GHz, tested with Prime95, crashed during the actual games but the computer (3.9 GHz only the BC2 game).
All in all, I still recommend the CPU for all the a 4-core (or less) have an AM2 plus (+) or a Board AM3 (+).
Clear the SBs (2500 / 2600K) from Intel are faster, but if really 6 full cores are called for then you are with the AMD 6-core not too bad set, especially since he is almost a bargain with currently around 150 EUR.