Monero mining gives me a much lower watt consumption, 6 580s at the wall for me was pull 1000w for ether and 6 700w for monero.
If 6x580's is pulling 1000w@the wall for ether, you're doing something wrong.
It should be way below 800w, i've seen as low as 700 with 8xx mv settings.
I can only get it to 850w in windows. When I run it in ethos it just goes up that high.