my EVGA 1070 ti has one 8 pin peci plug.
I have the EVGA GeForce GTX 1070 Ti SC GAMING so
QuintLeo is right
MY 1080 has 2
That's what I thought, but if you watch VoskCoin, he uses one 1000 watt EVGA Gold to power 6 cards.
https://youtu.be/QBmZG4pnr6ASo is he splitting each 6 pin to (2) 8 pins?
form what the video shows hes using one splitter per card and you still need to power the pcei raisers cards, i don't use the power plug on the MB sense i use powered raiser cards, you don't need to use the four pin power plugs on the MB you can but i don't think it mater much unless your not using powered raiser cards.
I don't use ATX pSU i use server PSU with a DC 12V 160W 24Pin Pico ATX Switch that only powers the MB and SSD an power the EPS plug on the MB plugged directly into the PSU with a cable i made from idea's off the forums here.