no it s not you need 1200w (undervolt also)
i have 5x on 1000w they undervolt, not sure anymore how much it was but it was close to 1000w on eth was dualmining i think, now i remove dual because i keep my ether
1000W for 6 GPU is enough. With proper undervolting absolutly no problem.
right i check my ring undervolt it s using 752W for 5x 570 on ether
but if you do dualmining it s use up to 1000