Oh right, this is the right thread for this post I posted elsewhere, oops :x
You need to enable Load Line Calibration when overclocking on these boards as the Vdroop is terrible on them.
I need to use 1.3v for 3.8 Ghz, and 1.475v for 4.2 Ghz with Standard LLC, or 1.25v and 1.425v with LLC enabled (the voltage still drops by 0.029v under load with LLC enabled, but it drops by something like 0.075v with it set to standard).