Yes, that was my point. Pulling everything through one rail is a bad idea. It would work fine with two or three 1070's but I would spread the amperage across multiple rails when possible. I guess I misunderstood your post.
Correct, 2 cards max at 1070 or ti per rail. 1 x 1070ti = 200 to 230 watts at 100% with peaks to 290 watt for less than 50ms. 2 of these per rail max, personally I would do 1 per rail. 16 awg cables = 300 watts per cable in my opinion, or 1 card.
OK that makes a lot of sense now that I understand.
I don't really have to worry about this stuff personally, because I use dual PSUs on both my rigs, and they are both using 1 x 850W ATX PSU for mobo, risers and 1st 2 GPUS with all the extra GPU PCIe 12V connections from a modded 1200W server PSU. 4 x 1060 6GB, 4 x 1070, 2 x 1080 on 2 mobos, etc all pulling around 1400-1500W @ 240vac mining with everything at powerlimit 85% (currently mining Bulwark - NIST5 algo).
I think the OP must be at factory clocks, powerlimit, etc - so yes I agree that balancing outputs over 12V rails would be a good idea.
I really want to know if changing the pagefile size helps, but I can't remember if equihash uses a lot of RAM or if the equihash mining software advises using a big pagefile - I suggested that because I remember when I swapped from Linux back to Windows (to get easier to use ccminer releases) the first thing I had to do was give Windows a huge pagefile - but I can't remember what I was mining at the time.