2X1000W, Corsair RM1000X (already ordered add2PSU but it has not arrived yet, so thus manual start)
I was unable to make work 3 390 (stock) on 1000W PSU, it failed in a few minutes of work, have to use 3 1000W PSU for 6 390. But 2 1200W can handle 6 390 in all my tests.
I understand but "citronick" previous post use EVGA 1600W 6X390 GPU. So not understand why is not enough 2X1000W PSU in this case?! Thank you Claymore!
I use -100mV/1015mhz/1500mhz setting using MSI Afterburner utility -- this setting under-clocks the 390s to be just under 1600 (sometimes it goes above 1600w).
But fellow riggers have advised me not to do this because it will surely kill the PSU...
If you want to keep the 6 card setup at stock clock speeds, confirm you need 2 PSUs or even 3 PSUs like Claymore mentioned.
Each 390 at stock is I think 270w each. So 270 x 6 is already 1620w excluding mobo etc.
It was rock stable with older versions and other miners. 
