Well, after another evening of tweaking, I managed to get 4953MHz. Just 2 off 10th place in the hwbot rankings (which I've just discovered and am pleased to see a few of you lot are on). I also nudged down my 1M PI time a little:



Pretty proud of myself as this is my first proper kind of opportunity to OC without much limiting me (except lack of a chiller / liquid nitrogen), but I've gotta say that if you intend to overclock these CPUs, then the UD3 range is king. Sorry to nudge you down andressergio, but it does take a lot of tweaking to get into this territory, so kudos to you, and Huuuuge kudos to Jor3lbr!