So you start at ~800w from the wall. Effeciency numbers coming from jonnyguru TPQ-1200w test since I'm assuming this is the PSU you were using??
800w AC * 87.5% efficiency = 700w
That still leaves us with the power draw from the entire mobo INCLUDING overvolted and overclocked NB. Plus ram that is most likely overvolted/overclocked + PCI-E slot + SB + PWM and all other parts on the mobo that consume power. Stock X58 NB is like 35w or 45w. Who knows how it scales in power draw when overvolted/overclocked, but it can't be great since it's on 90nm process node. Just guessing, I'd say you are right around the majic 525-600w DC figure loaded with 6c/12t in wprime. That is still a HUGE power draw though! The point I'm trying to make though is that when talking about sizing PSU's and deciding on how many to run, the difference between needing 600w or 800w is huge.
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