Do Nvidia Tesla M40 gpus draw power from the PCIe slot or do they take everything from the EPS 12v plug?

[ShadowChaser]

As title states - I'm throwing 2 custom cooled Tesla M40s into my machine learning rig alongside an ex-mined P106-90. I'm worried about blowing the pcie slots on my motherboard (Asus Z170-A) as if all 3 gpus take the 75W from the mobo, I am quite worried about the motherboard just going poof. 

 

I'm hoping that someone who's worked with these gpus know whether they get all their power from the power cable or if they draw power from both the 8 pin and the pcie slot, or at least can point me towards documentation on the matter.

[Helpful Tech Witch]

they shouldnt blow it, the spec is to draw from the motherboard.

[ShadowChaser]

1 minute ago, HelpfulTechWizard said:

they shouldnt blow it, the spec is to draw from the motherboard.

M40s have a 250W max power draw and a 150W operational power draw, how would they pull that from the motherboard when the pcie slot power spec is rated for 75W? Am I missing something?

[Helpful Tech Witch]

1 minute ago, ShadowChaser said:

M40s have a 250W max power draw and a 150W operational power draw, how would they pull that from the motherboard when the pcie slot power spec is rated for 75W? Am I missing something?

no, i meant the pci spec is to draw from the motherboard, so you would be fine. Unless you are using pcie bifourcation?

[WhitetailAni]

1 minute ago, ShadowChaser said:

M40s have a 250W max power draw and a 150W operational power draw, how would they pull that from the motherboard when the pcie slot power spec is rated for 75W? Am I missing something?

Well, they have an EPS power connector.

They will pull power from both the PCIe slot and the power connector.

[Sakkura]

It's the compute version of the original Titan X, which would average around 50W drawn from the PCIe slot at full load. Don't have data to confirm the M40 does the same, but it's likely.

[igormp]

9 minutes ago, ShadowChaser said:

I'm hoping that someone who's worked with these gpus know whether they get all their power from the power cable or if they draw power from both the 8 pin and the pcie slot, or at least can point me towards documentation on the matter.

On nvidia, most of the power is used from the 8 pin, the power from the PCIe slot is mostly used for the peripherals on the board instead of the actual GPU core.

[ShadowChaser]

5 minutes ago, HelpfulTechWizard said:

no, i meant the pci spec is to draw from the motherboard, so you would be fine. Unless you are using pcie bifourcation?

I will have to in order to use 3 gpus (technically 4 total) on this board. I will have 2x Tesla M40s for the heavy machine learning, the P106 handles my 3d printer spaghetti detection, and I have a GT 730 idling 99% of the time in a modded 1x slot in case I need to pull up a gui.

 

If all 3 big gpus are running full tilt (which may very well happen frequently) they'll be pulling 225W from the pcie slots, plus another 5 or 10 for the GT730, which I am not comfortable with. Considering that I will also be powering dual channel memory, a pcie ssd, and potentially more, I'm not feeling very good about this if they do need to pull from the slots.

 

5 minutes ago, FakeKGB said:

Well, they have an EPS power connector.

They will pull power from both the PCIe slot and the power connector.

Any idea if it's something like 25 or 35W or if it's the full 75?

 

4 minutes ago, Sakkura said:

It's the compute version of the original Titan X, which would average around 50W drawn from the PCIe slot at full load. Don't have data to confirm the M40 does the same, but it's likely.

 

2 minutes ago, igormp said:

On nvidia, most of the power is used from the 8 pin, the power from the PCIe slot is mostly used for the peripherals on the board instead of the actual GPU core.

This was what I thought, but I wanted hard numbers because I did some quick maths and just about had a heart attack

[MarcWolfe]

The 12 volt draw spec is more like 66 watts by the way. The rest of the 75 watts is 3.3 volt.