Sorry, but 950mv is not doing 80-83w. I'm assuming you're looking at HWinfo or GPU-z which are not complete, and/or you're forgetting to add in your idle (15w) which still would be too low.
Including idle, at the wall, i see 105-110 @ 850-860mv (1200-1265h/r depending on mem type)
Including idle, at the wall, i see 105-110 @ 850-860mv (1200-1265h/r depending on mem type)
Yeah, you should add about 20-25% to the numbers you're getting in HWinfo.
There's also the PSU quality to consider, you should strive to get as close to 50% PSU as you can where the efficiency is at max.
There can be quite a difference if you're using Gold or a Titanium PSU.
I think we need to be careful w/ this PSU advice. The specific efficiency curve totally depends on the PSU, though at 110-120v, peak efficiency seems to occur more commonly around 33%, rather than 50% load - at least for high wattage evga/corsair PSUs. But we should avoid giving the impression someone might consider buying a second PSU just to keep load at 33-50%, given that the efficiency gap between 20% and 80% load is generally only a couple percentage points.
The best advice is simply to get the best rated PSU you can (gold or platinum - titanium prices tend to be absurd,) make sure you are utilizing your PSU at least 20-25%, and go 240v if possible.
Here's an example eff curve for a Corsair ax1500i:
