How much did you push that CPU?
If that power supply overstated it's continuous power output and you take into account it's 70%? efficiency it might of been pushed right to the edge.
Guess I won't be recommending that PSU for a GPU that requires two 8 pins. The only reason I got mine, because it was like R625 at the time with kalahari voucher and because it was blue.
PS. That RM1000 has 83.3A on the 12v and it's gold rated.
996w
Man, that's overkill.
CPU is running ar 4.9 Ghz