Things I have not tried, (and will tonight) include using a different 8 pin motherboard header instead of the hard wired one in my psu, although I really, really doubt it'll make a difference - and upping the NB voltage to 1.3 and turning LLC off.
unsuccessful. 1.3 northbridge Short of another PSU or ram I dunno what to say. It's sad amd won't chime in here.
It's interesting - I can replicate two conditions.
1) hard lock on the desktop, frozen picture, no input.
2) Goes black, requires hard power-down.
Now #1 is either: ram is getting voltage spiked when the system goes into load and can't handle it (which I doubt, becuase undervolting the ram or changing the mhz makes zero difference) or I'm getting severe VDROP or Vdroop is going way too far and locking things up due to not enough voltage to the cpu. It's not getting hot.
#2 is most certainly a heat shutdown - as it only occurs when I go buck nutty on the voltage in an attempt to stabilize the system or compensate for what I think is VDROP.
Okay, so, I'm sad that I'm not getting a reply to this.
So since previous, I've tried absolutely everything I mentioned I would try. 1200w psu. New ram. New cooler, getting it extremely cold: no dice. It's simply going to lock up above 4.5ghz, no matter what.
It's important to note I can put absolutely everything stock, with the boost clock set to 4.7, and the base clock to 4.5, and it's perfectly stable. At 4.7 and 5.0, lockups.