yes but now i know exactly how much one card consume, the system apparently consume 70w when three card are mining
each card 147w mining at 22MH, same thing as 390, so those who were saying that amd was better, were wrong
possible lower with a reference 970 due to less components on board plus less fan, 140w estimate
I have 5x R9 390 XFX cards. 137 MHz with 870W from the wall, so that is 6.35J /MH, that is better than the 970.