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Go to SolutionOptiplex 970 not accepting 2 GPU
Hello - hoping to get some insight. I am running the following:
MB: i5-2400 @ 3.1GHz / RAM: 16GB / PSU Pystar 1000W (80 plus gold)
Windows 10 Pro (v. 20H2) / BIOS: A22
installed and working GPU: Nvidia 1060 3 GB installed on PCI-e slot 1.
Issue: I tried installing a second GPU Nvidia 1050 on PCI-e slot 2 or 4, but the PC will not boot.
If I swap them around, the 1050 works by itself, but not combined together. I tried using a riser, same issue.
I am using Nvidia driver 497.29
With both cards installed the PC will not boot up. Thanks for any help!
726
1
Posted January 12th, 2022 08:00
you have optiplex 790 MT. the pcie slot x 4 or 1 are too weak in power delivery to support a 1050. although you have a 1000 w psu, that power is mainly in its 12V PCIe connectors/rails. the power drawn by motherboard is still determined by how much the motherboard needs. the upper limit of each PCIe power support is still determined by motherboard. A 1000w psu delivers same amt power in those slots as the Dell stock psu.
790 tech guide says the x 16 slot is 35w max, x4 slot is 25w, x 1 slot is 10w
722
0
Posted January 12th, 2022 08:00
Thank you. To potential solve this I also have two risers and a PCIe splitter 1 to 4. I tried putting it in either Slot 1 or 2. The PC would not boot up. I see the CPU fan running but not the GPU. I tried one GPU and then the other. No difference. Is this MB unable to support two GPU?
Using the Riser only works if I use Slot 2. It would to function using the splitter.
719
0
Posted January 12th, 2022 09:00
Ok - thank you. I just tested but no luck. Basically I need a new MB that will support both cards.
redxps630
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720
0
Posted January 12th, 2022 09:00
the motherboard black and blue x 16 slot (physical x 16 both and electrical x16 + x4) can support two weak gpu at same time, I think. to prove this you may use two low power gpu such as HD6350 (20w).
but to support 1060 + 1050 card with TDP of 120w and 75 w is taxing the mobo way over board.
although the tech guide says 35w max for pciex16 slot, it is known that a single 75w card such as 1050 is supported. this is already above-the-spec use. when you use 1060 w 6 pin the power issue is ameliorated by the 6 pin supplementary power. I suppose to prove the concept, you may also try two gpu both w supplementary 6 pin in two x 16 slot to see. but playing with mobo that has weak power upper limit in PCIe slot is risky.
also we do not know whether the 35w max in x 16 slot is determined by Dell stock psu rating, or actual upper limit of power rating for the slot. a standard x 16 slot is rated to support up to 75w.