Power supply calculator: https://outervision.com/power-supply-calculator
 
It's all theoretical... - mine hard!
 
Edit: Well, the minimum requirement (EVGA / Specs) for one (!) gpu is listed with 500W with a total power draw of 170W. Maybe, you should be more generous with your psu's.

Thanks guys. According to that calculator I should have more than enough PSU capacity between the 2 units to handle the operation. Assuming that calculator is correct, does it matter what adapters I use to connect the GPUs to the PSU?

For example, could I use adapters and splitters to connect additional cards to the 6pin ports on the PSU even though theyre labled for Peripheral & SATA? If so, how many would be needed per card?
 
 

No Info Here

I am still confused as to what cables can be used. The GPUs have 2 x 8pin ports on them but shipped with adapters the turn each of the 8pins into 2 x 6 pins. Do they both need to be plugged in? What cables should I be using to connect the GPUs?

No Info Here

 
No Info Here

If you're going to get serious about hardware with six GTX 1070 FTW2s, then you need to get serious about a power supply..A GTX 1070 FTW2 is rated at 215 watts max power draw.
 
6 x 215W = 1290W..290W @ 12V = 107.5A..This is all 'on paper' and theoretical power draw at max load..Watts-to-Amps converter here.
 
An EVGA 1300W G2 unit is rated for 108.3A on the single +12V rail..A 1600W G2, P2, T2 is rated for 133.3A on the single +12V rail..Amps is what you need to watch..Amps trumps watts all day, every day..A 1300W unit will likely not be enough to run your box, pretty much guaranteed..Amps is what will trip the PSU's OCP (Over Current Protection) if exceeded.
 
Long story short = You should get an EVGA 1600W unit and two additional 8 pin (or 6+2 pin) cables for it by contacting either EVGA Customer Service or from CableMod (as linked to by Chris21010), or you might use two 6 pin connectors from the PSU into one 8 pin for the graphics cards using the adapters as needed that comes with the cards.
 
Edit: Forgot to say that if you use the EVGA Power Meter, you'll receive a discount code in your email that's good for 10% off any EVGA PSU in the EVGA U.S. shopping cart andt is valid for 30 days, just for using the Power Meter.
 

Thanks guys. This is great.

I currently have 5 of the 6 cards powered and connected at the moment using 3 separate 750w PSUs (lack of ports and didn't want to wait for the future, larger PSU to be delivered). For some reason, I can't get all 5 of the GPUs to be recognized by the PC. Disabling any 2 allows any of the other 3 to register upon reboot.

I also noticed that the CPU is running at 100% when using the Genoil miner and it moves extremely slow.

Using the following:

Intel Celeron G3900 Dual-core 2.80 GHz

MSI Pro Solution Intel Z170A LGA 1151 DDR4 USB 3.1 ATX (have updated the mobo bios)

T-Module PCI-E Express 1x to 16x Powered Riser Cables 0.6m USB3.0 SATA to Molex 4 Pin

Any idea what the issue could be?

What would be a good replacement CPU?

This isn't a folding cpu, thread count doesnt matter. At this point I would go and search the web for answers as I do not think there are enough people here with mining rigs to offer the help you are looking for.

if you are using 1x pcie risers you will not be using 20 lanes. you could put 12 1x risers on that CPU and it not care in regards to pcie lanes.
 
also to my previous comment about limit of 3 displays, this may be a limit to the internal GPU on the CPU limiting monitors and not a limit to pcie devices. i just do not have enough experience with that many GPU's using risers to know if its a CPU thing or a motherboard thing.

Update on this end:

I currently have it recognizing 4 GPUs...
 
Ports 1,3,5 (small ports) all work
Port 6 (large port) works.
 
The other two do not...

I have this one:
(wont let me post links yet)
MSI Z170A SLI PLUS
 

Chris21010
when mining the GPU should never reach TDP 

 Depends on the coin you are mining - ETH mining routinely pushes cards to full TDP, ZEC usually you can run at 70-80% of TDP and still get very close to max production.
 
 Also, when you're mining you'll get "spikes" on power usage that don't show in monitor programs (you need a good O'Scope to see them), and can shut the machine down if your PS doesn't have enough capacity in reserve to handle the spikes - which is one of the reasons I pretty much never run a PS at a constant load of more than about 80% of it's rated capacity, even good EVGA or Seasonic units, on any GPU rig.
 
 
 M.2 to GPU convertors seem to not work well - I've seen several reports (at least one from a highly trusted source) of them frying or just not working in the bitcoin.talk forums.