Why X570 Aorus Master not supporting 3 cards in mining

[neil_pattrick]

Hi

I earlier had Gigabyte Aorus 2070 super and added MSI Suprim X RTX 3090 for machine learning and deep learning connected to my motherboard. They used to work fine and I was able to use them.

Last month decided to join mining as a casual miner, so started putting the above 2 GPU for some additional usage. I recently bought Asus ROG RTX 3070 to add some more hashes to the RIG.

This is just to show you what I mean when I say 1,2,3,4 with PCIe numbering.

But the problem is the 3070 and 3090 do not work together. This are my results the settings I have tried with BIOS and results I got.

PCIe Lane Generation	PCIEx16 Bifurcation	Result	PCIE Port Config/ GPU Placement
PCIE-2	4*4	Detect all GPU, 3090 CUDA not detected	1-2070s, 2nd-3070, 3rd-3090
PCIE-3	4*4	Detect all GPU, 3090 CUDA not detected	1-2070s, 2nd-3070, 3rd-3091
Auto	4*4	3070 not detected, 3090 No CUDA	1-2070s, 2nd-3070, 3rd-3092
Auto	1*8/2*4	Only 2070s	1-2070s, 2nd-3090, 3rd-3070
PCIE-4	1*8/2*4	Only 2070s	1-2070s, 2nd-3090, 3rd-3071
PCIE-4	4*4	Only 2070s	1-2070s, 2nd-3090, 3rd-3072
PCIE-4	4*4	Only 2070s	1-2070s, 2nd-3090, 3rd-3070
Auto	4*4	3070 not detected, 3090 No CUDA	1-2070s, 2nd-3090, 3rd-3071
Auto	Auto	Only 2070s	1-2070s, 2nd-3090, 3rd-3072
Auto	Auto	Only 2070s	1-2070s, 2nd-3090 (with 2 GPU only)
PCIE-2	Auto	2070s + 3090 Detected and shows CUDA	1-2070s, 2nd-3090 (with 2 GPU only)
PCIE-2	Auto	3070 not detected, 2070s+3090 CUDA Works	1-2070s, 2nd-3090, 3rd-3071
PCIE-2	Auto	3070 not detected, 2070s+3090 CUDA Works	1-2070s, 2nd-3090, 4th-3070
PCIE-2	1*8/2*4	3070 not detected, 2070s+3090 CUDA Works	1-2070s, 2nd-3090, 3rd-3070
PCIE-2	1*8/2*4	3070 not detected, 2070s+3090 CUDA Works	1-2070s, 2nd-3090, 4th-3070
PCIE-2	Auto	2070s + 3070 Detected and shows CUDA	1-2070s, 2nd-3070 (with 2 GPU only)
PCIE-2	2*4/1*8	Detect all GPU, 3090 CUDA not detected	1-2070s, 2nd-3070, 3rd-3090
PCIE-2	2*4/1*8	2070s + 3070 Detected and shows CUDA	1-2070s, 2nd-3070, 4th-3090
PCIE-2	1*8/2*4	3090 not detected	1-3070s, 2nd-3090 (with 2 GPU only)
PCIE-2	Auto	3090 not detected	1-3070s, 2nd-3090 (with 2 GPU only)
Auto	Auto	3090 not detected	1-3070s, 2nd-3090 (with 2 GPU only)

Why does 3070 and 3090 do not work together.

[wertigon]

According to the specifications of the motherboard, the slots work like this:

1. x16 if slot 2 is not occupied, x8 otherwise. Powered by CPU.
2. x8, Powered by CPU.
3. x1, Powered by chipset and requires a Ryzen 3rd gen (3000+ series I think?)
4. x4, Powered by chipset and requires a Ryzen 3rd gen

According to the manual you should have 3090 in slot 1, 3070 in slot 2 and 2070 in slot 4, and bifurb should be x8/x8/x4.

However, it is possible that CUDA requires x8 PCIe lanes, or that cards require to be part of the CPU lanes, in which case you need to either get an x8/x8/x4 from CPU motherboard, or perhaps a Threadripper build.

This site here might have better info: GPUDirect RDMA :: CUDA Toolkit Documentation

[MisteryAngel]

@wertigon

it is possible that CUDA requires x8 PCIe lanes

Highly likely yes.
Sli on Nvidia does not work on 4x bus either.

[aBav.Normie-Pleb]

Hooray for the ASUS Pro WS X570-ACE, the only AM4 motherboard with an electrical x8 slot coming from the chipset.