im running 2 vega 64's  i my hash for ethereum is around 43 out of each card steady, with monero and sumokoin, i get 1020 out of each card steady but have to do some thing in the wattman... you have to have 8gigs of ram to open the hbcc memory in the global settings.  turn that all the way up when doing cryptonight coins. also with monero and sumokoin and other cyrptonight coins you can us the card as 2 threads. do that in the config file. as far as power usage i dont have a thing to measure it. but i do know my bill was about 30 dollars more then usual.