https://forums.evga.com/N...A-750-G2-m2748906.aspx

Because you got dual 8pin cards the only way to make it work is with cable mods dual 6+2pin cables. Dual 8pin power is rated up to 375W, which is double what a 1070ti is capable of, stupid overkill design.

As for power requirements, sum up the TDP of all the parts and divide by two or three and multiply that by 1.2 to get the safe wattage of your 2 or 3 power supplies.

And as I said in the other thread your cpu, board, and risers should all be powered by the same power supply.

USB-cabled style risers do NOT transmit power from the motherboard.
It is SAFER to put the riser and the GPU on that riser on the same power supply, because those MIGHT share power through the GPU.
On a many-card rig it is usually a good idea to go with GPUs that use the fewest power connections possible, to avoid having to use "splitters" that can be additional points of failure.
For the 1070 ti, that would mean going with an EVGA SC model (single 8-pin connector) instead of a EVGA FTW model (2 power connectors).
 
 It is BETTER if you can also power the motherboard from the same power supply, but it's not an absolute requirement, and if you use a multiple power supply setup (which would be overkill in general for 6 x 1070 ti cards unless you are pushing them VERY VERY hard for max hashrate) you don't have the OPTION to do so.
 For a single-power supply rig, it's not an issue at all as everything is getting powered from the same source.
 
Using SATA in any way shape or form to power risers is HIGH RISK - the SATA power connector ITSELF is only rated for 54 watts of 12VDC while the PCI-E bus is rated to draw up to 75 *AND* the voltage-conversion circuitry on the riser that turns the 12VDC into the PCI-E bus provided voltages will ALSO eat a few watts in conversion inefficiency.
 
It MIGHT work, if you are running the cards at a low TDP setting for high efficiency (you will HAVE to do that to run 6 of them on a single 1000 watt supply) *AND IF* the card balances the total load so the majority of the draw is via the PCI-E power connector(s) on the card - but that is NOT always the case, and there have been documented cases of GPUs pulling spikes exceeding 80 watts out of the PCI-E bus.
 Both the PCI-E 6-pin adapter and the common "MOLEX" peripheral adapter are rated for well over 100 watts and are safe to power risers from, as long as you don't overstress the WIRING (running more than 2 risers from one "Molex chain" can sometimes be an issue due to the WIRING not being sized properly to handle that much load, it's not an issue with PCI-E power unless you start splitting cables out, then it MIGHT be).
 

 
Running 6 of them at low enough TDP settings to work on a 1000?
Should be no tribble at all.
 
 
 Dual PCI-E cables I have seen have NEVER had enough space between the connectors to allow powering a PCI-E riser from the same cable as the card - in THEORY it might work on a "low profile" short card, but the length would be real iffy even then.
 

I have been told of "dual power connnector" cards that will run with only one power connnector - but I've never SEEN one.
My selection of such cards is fairly small though - some R9 280x, R9 290, a single Vega 56, and all of my 1080 ti cards are dual power connector.
I think one of my 1080 cards might be - MSI high-end "gaming" model.
 
They ALL fail, and some of them give a "connect power" type error right after the BIOS bootup screen, when only one power connection is correctly hooked up - long before their TDP could possibly be set lower.
 

Oh and as for the 8 pin, like QuintLeo, I've heard of them for some reason too, but never seen one.
 

6 1070 ti cards should run COMFORTABLY on a single 1000 watt PS, if you use a TDP setting in the 102-110 range (most efficient range).
I run 5 of them AND a rather power-hungry AMD 8xxx series CPU setup on a single 850 with plenty of headroom on the PS - and 700 watts (give or take 20) power draw AT THE WALL.
 
Only reason I use the AMD setup is that it's leftover parts from my Folding days, and the extra power draw of the 8xxx CPU is made up for by having it mine Monero.
 
Efficiency of a power supply is NOT related to it's wattage capacity level - there are a lot of Titanium-level supplies at lower wattage levels then the common 1200-1300 watt Gold rated options.
With that said, higher efficiency power supplies don't seem to exist much below the 300 watt level, and are less common under about 450.