I said more than once that my 1050W Cougar PSU is at its limits with two 780s @ 1212mv + the 3930k @ 4.65 Ghz (1.36v, 0 LLC)
It is around 800W, plus the rest of the rig (HDDs, SSDs, 15 fans, H100...)
I bet I'm around 900-950W with all this. Testing the PSU efficiency I would say.
EDIT: clarified 3930k voltage