Personally i would probably go with something like 2x evga 1000 on one 15a 120v breaker. Flip the power bar switch, both turn on at same time, voltage should be the same (mines are very stable). Plenty of cables.
Great efficiency, the draw put them at optimal load. Meh. A bit expensive but quiet and reliable, 10 years warranty.
I think Bitmain said if they arent powered at the same time, the controller need to be powered last. (Probably because the board don't have any draw until the controller is on).
Only way I would mix is if you are not mixing on hasing boards. If you power entire hashing board from one then yes... should be ok.
But if you do mix PSU's on same hashing board it will void warranty if bitmain catches you.
I get what you mean, indeed any sort of mixing PSU for a single board is a big nono. Warranty aside, if they have different voltage, i think it can fuck things up.
But that remind me that there's a uneven amount of boards, so you could go with one 1000/1300 and one 750, powering 2 board on the 1000 and 1 board + controller on the 750. At this rate you might as well get a 1600 and do;
3x 6pin + 6+2pin cables, 1 cable (two connector) per board
and 3x 6pin cables , 1 per board
This would fill the 6 of the 9 VGA/PCI-e sockets in the PSU and probably balance the load fine in the cables i think.
One more 6pin for the controller. 7/9 VGA used, you still have some spare room.
The 1600w has a wooping 9 VGA connector and
apparently come with 9x 8pin (6+2) and 5x 6pin. Thats a huge amount of cables, i'm impressed.
They should be 16AWG, since the ones on all my G2 are.
Might be worth considering forking over the 300$ for the PSU, maybe. IF you don't already have the 750-1300s on hand anyways.
