I have the DS4 and a Thermalright ultra extreme and it hits the nortbridge HS but is somehow still mountable.

It seems like it moves the heatsink base of the ultra a few mm offcenter.

Im having trouble overclocking this effectivly since i dont know the default voltages of anything but the cpu. All settings are +x.xx over standard but since only current cpu voltage is displayed.
Anyone know all the default voltages and how much you can safely push them?