Even 4 x 570 is at the limit of this corsair cx750.
I would not risk it with more than 3x 570 and that's single mining only.
Dual mining 570 can reach 150 watts
I was thinking 3 would be good for this and I dont know when I could add the 4 with finding a good price
So should my hashrate go up to 400 sol and drop to 60 sol within an hours time or should it stay consistent with say 270 sol