I have evga 1000G. This PSU comes stock with 2 cables that work for 1080ti. I tdp around 70% on 1080ti already tested. They stay around 170Wx4 = ~680w plus the rest goes up to around 800w from the wall. This fits in the 80% push for the PSU which I think it's healthy.
I would have gone with evga 1600w PSU but they are ridiculously out of stock and didn't want to wait. As soon as the bigger psu comes in stock I am ordering it and I'll make another 4 or 5x 1070s rig with the 1000w PSU.
So you mean you have a couple of 8+8 pin cables?