Building a mining rig.  As the title says, I have an EVGA X79 Dark motherboard, and I have 6x EVGA 1070 FTW Hyrbirds for a mining rig, but only have three connected for now. I have 6x USB3.0 risers, an intel core i7-3930k LGA 2011 BX80619I73930K processor, and 32GB or RAM.  The mobo, processor, and RAM were from my old personal PC. 
 
So I dont know what I am doing wrong, does my BIOS need specific settings to see all GPU's?   I can boot into Windows 10 x64 just fine and see the main GPU. 

running the latest bios.  Yeah I was thinking plugging all 6 GPUs would be required in this situation, and then testing each GPU one by one.
 
but no specific setting changes in BIOS required? 

Chris21010
the only setting in the bios that i can think of that is relevant would simply change the pcie version from 1 through 3, maybe just 1 or 2. though this isnt a setting that needs to be changed as it should automatically detect and set this accordingly. there wouldnt happen to be switches on that board to enable/disable pcie slots? i know the x99 FTW-K has one of these.

6 gpu's, only one showing. 5 dipswitches.. it's possible all of the dipswitches are in the off position. Would be a great spot to start.

wow would of never thought of looking for a physical switch... il go look right now.  this is the BIOS guide fyi

The physical switches worked for the three I have installed right now.  after work il install the rest.

It has 40...  so if im using the PCI-E 1x USB3.0 risers how many can I have?  CPU is Intel BX80619I73930K

you plug in the 6-pin VGA connector to the board. this is kinda needed if you are running a lot of cards as each pci-e slow will draw ~75W.

 

statik83
just google "150-SE-E789_BIOS_Guide"
 

X79 Chipset Motherboards

• Support Manual for EVGA X79 Dark (150-SE-E789) - visual guide - BIOS Guide
• EVGA X79 Dark (150-SE-E789-K2) - visual guide

 
On this "6-pin power connection for PCI-E..." make sure you also set it in the Bios. Page 14 in the above Bios Guide.
This cable is a Standard 6-Pin PCie Graphics Cable NOT SATA or Peripheral Power Cable. So you need 7 Graphics Cables in all.
But you need 12 Each 8-Pin Graphics Card Power Cables for the GTX 1070 FTW Hybrid Graphics Card so you really need 12 8-Pin and 1 6-Pin 13 in all.
Each Card must have Both 8-Pin Power Connectors Connected to work.
But this is really only needed if you are connecting 3 or More Graphics Cards to the Motherboard not when using USB Risers.
That is using PCI-E 1x USB 3.0 risers it will be whatever they will allow as the MB can really only support 5 Graphics Cards at X4
What is the Make and Model of your USB3.0 risers and how are you Powering them?
Make sure the ECO Switch is OFF on your Power Supply.
 From Page 24 in above Manual Link.
PE6 – x8 (x4 if PE5 used) (1x4) ***
 
*** This is where you will have issues.
But using PCI-E 1x USB 3.0 Risers Changes Everything.

Chris21010
I mean you could grab one of those molex to 6-pin adapters. It just wouldn't look nice.

Yes that would work for the Motherboard 6-Pin but I do no think the OP cares what this monster looks like as long a it works.
For 6 Each 2 Each 8-Pin Graphics Cards the OP really need this EVGA SuperNOVA 1600 G2, 80+ GOLD 1600W, Fully Modular, 10 Year Warranty, Includes FREE Power On Self Tester Power Supply 120-G2-1600-X1 (9x 8pin (6+2), 5x 6pin) to support this Monster. The 1200 only has 6x 8pin (6+2), 2x 6pin
You have to spend Money to Make Money they say.
I would get Two EVGA SuperNOVA 1300 G2, 80+ GOLD 1300W, Fully Modular, 10 Year Warranty, Includes FREE Power On Self Tester Power Supply 120-G2-1300-XR
or Two EVGA SuperNOVA 1200 P2, 80+ PLATINUM 1200W, Fully Modular, EVGA ECO Mode, 10 Year Warranty, Includes FREE Power On Self Tester Power Supply 220-P2-1200-X1
 
You may find more and better support here https://bitcointalk.org/ as this is not really a Mining Forum or Community nor do we have experts in this subject mater. 

Be careful Mixing PSU Cables of different brands can Cause Shorts and Even Fires.
And will also void your warranty on all your hardware that may be damaged by them.