Help a n00b miner set up a rig

Hi guys!

I am trying to set up a 4x1080ti’s rig with one EVGA 1200w power supply. I am posting here just to make sure what I’ll be doing is safe. After some googling, many people also have the same setup as long as the 1080ti’s are undervolted to around 70-80% (which also what I’m planning to do).

Here are the relevant equipments:

  1. 4x EVGA 1080ti SC (requires 8 + 6 pin)
  2. 4x risers with molex, 6-pin, and SATA connections (won’t be using the SATA)
  3. 1x EVGA 1200 P2 power supply

The PSU has the following relevant ports:

  1. 6x VGA
  2. 2x PERIF

The following relevant cables are included:

  1. 4x 8(6+2)-pin PCIe cables
  2. 2x 6-pin + 8(6+2)-pin PCIe cables
  3. 1x 3 Molex cable
  4. 1x 2 Molex cable

What I’m thinking of doing is the following:

  1. Plug in the 4x 8pin PCIe cables to the 8-pin power needed by each 1080ti. This uses 4 VGA ports. 1 cable → 1 GPU
  2. Plug in the 2x 6+8 PCIe split cables to the 6-pin power needed by each 1080ti. This uses the remaining 2 VGA ports. 1 cable → 2 GPU
  3. Power up the 4x risers using the 2 Molex cables. 2 risers per 1 Molex cable.
  4. The above will be done one by one per GPU, and I will install the GPU as well as undervolting it and checking the power draw at the wall before moving on to the next one.

My questions are:

  1. Is the plan above safe to do? Any suggestions?
  2. What if I had 4x 1080ti’s that each needs an 8-pin+8-pin? Would it be possible to fit them all in one EVGA 1200w?

Thanks in advance!

if the gpu is a 8 pin + 6 pin you can use the single combo power cable 8 pin + 6 pin to power it

if the gpu is 8 + 8 pin you would need a single combo cable that is 8 pin with a 6 + 2 pin or you would need two single 8 pin power cables

keep in mind a 1080 Ti at stock runs between 235w to 265w

  1. if you have to use single 8 pin cables, I don’t think a 1200w evga has 8 vga power slots


Thanks for the reply!

  1. That’s also what the EVGA customer service told me. But I thought a single cable can only deliver up to 150w max? Whereas 1080ti’s need more than that.

  2. Ok.

I think you will be pushing it on 1200 watts, to run all your risers etc and the 4 cards, i set up a single 1080ti with two 1080 and the risers on an 800 watt psu and it would trip the PSU about every 3 to 4 hours. i had to resort to the second psu to run the other 4 1080’s and half the risers to keep it stable. runs for a week at a time no problems. i would try just 3 cards and see if it is stable first. if you have another psu you can use you can add it later if needed. good luck

Thanks for your reply!

My 1080ti’s actually draw around 200W each with 80% TDP. Note that I run my mobo+CPU from another PSU, so that the 1200W PSU is purely for the 4 1080ti’s. The power draw at the wall is around 850W, so I think this is safe for a 1200W PSU.