Well, I haven't had this before, but now that my OC's and voltages are much higher, the system just shuts down at the end of Jane Nash. No problem with single card, but quad-sli is a problem. 217@1.56875vcore, with GPU volts high enough to attain 815/1805/1220-50.
If I drop the GPU clocks and voltage slightly, it squeeks by with P45's runs. Trying for P46k, obviously.
Could it be my 2 yr old 1000w enermax PSU not providing enough power?