I can get it into windows at 500fsb which is 4.5ghz but it's no where near stable. I don't consider 1.45v HIGH as I had my Q6600 at 1.55 for the longest time, I do however love ocing the piss out of this 8400 and even in multi threaded apps this is faster, I have quite a few i.e. Supreme Commander, and a few of the Photoshops and the dual at 4.2ghz smokes the quad I had at 3.6ghz hands down.