https://abload.de/img/ethixstk.png
6*GTX 1060 2*3GB & 4*6GB at 57-61% Powerlimit. Power Consumption at the wall = 480W

Yes its lottery if you get a gtx 1060 with samsung memory. but if u get them, you get the best Hash/Watt ratio.

ETH Dual mining is not worth the trouble. You get less ETH and a lot of negative aspects such as more heat, more power, more problems.