Is it safe to mine with this idea of a setup?

[Vasllo]

I'm currently mining Ethereum with my gaming setup casually, ~30MH/s@100w.

 

Would it be safe to add 2 more GPUs to my rig just to mine? Maybe a couple 1070s, which would run similarly to my 1070 ti.

 

My Asus P8P67 Pro has 3 PCI-E slots, and my PSU has a forked 2x 6+2 PCI-E power cable, my idea would be to run the third card with a molex to 8pin PCI-E adaptor.

 

So my question is, is it safe for my motherboard to have 3 GPUs in it, possibly drawing as much as 125w from the slots?

 

And to lower the molex cable load, I could move one of the new GPUs to the x16 PCI-E slot so it can draw 75w from the mobo, instead of 25w on x4 or x8 slots, needing just 30w from the molex cable, would it be safe in this case?

 

Overall, are there any concerning points of failure in this idea?

[DoctorNick]

Eh.. No. 550W. No molex please

[Vasllo]

31 minutes ago, DoctorNick said:

Eh.. No. 550W. No molex please

As stated, each card will be setup to draw ~100w, so power won't be an issue, it can do 516w on the 12V rail. I don't like the molex too much either, but since it's going to be way under spec for power draw, I was wondering if it would be safe, or if it's a death trap in any scenario.

 

Also, I could do 2x molex -> 8pin to halve the load.

[WkdPaul]

* thread moved to the Folding@home, Boinc, and Coin Mining section *

[airborne spoon]

each PCI x16 slot on the MB has a max power draw of 75w everything else comes from the power plug on the card. If you're not using risers or anything and just throwing them into your MB in the PCI-E x16 slots then youre fine and good. If you are going to use PCI x1 riser cards then you will start getting into issues as sometimes the 75w draw is too intense for the 12v line on the molex and it melts down every couple months unless you build your own wire with heavier gauge wire.