Title: anyone using MSI Z270 with 4 or more GPU Post by: ggbtctalk000 on January 28, 2018, 03:35:50 AM i purchased several MSI Z270 for mining. First 2-3 board will recognize 4 GPU GTX 1080-s with no problem if I plug into specific magic combo: pcie slot 1,2,3,6 counting from top.
Now the rest of the motherboard will not recognize althought exactly same model, it can recognize up to 3 if i put into slot 3,5,6. I started plugging one by one and found the upstream bridge for each slot: 6 0.1.07 5 0.1c.6 4 ?? does not detect 3 0.1c.7 2 0.1c.2 1 0.1c.4 slot 4 is one of the slit slot (1,4) not sure why nothing appear when plug into this slot. Used lspci -t from linux and found that the ones that recognizes up to 3 has following pci tree: up stream -> nvidia pci address 00.1b.04 -> 3.0.0 00.1c.6 -> 5.0.0 00.1c.7 -> 6.0.0 No matter how I plug no other combination will work. This is best I can get. Now the working ones show following with 4 GPU-s detected: 0.1.0 -> 1.0.0 0.1b.4 -> 3.0.0 0.1c.2 -> 5.0.0 0.1c.7 -> 7.0.0 Not sure why the fuck? I may try checking BIOS version using dmidecode later. lspci -t with 4 GPU-s recognized. -[0000:00]-+-00.0 +-01.0-[01]--+-00.0 | \-00.1 +-08.0 +-14.0 +-14.2 +-16.0 +-17.0 +-1b.0-[02]-- +-1b.4-[03]--+-00.0 | \-00.1 +-1c.0-[04]-- +-1c.2-[05]--+-00.0 | \-00.1 +-1c.4-[06]----00.0 +-1c.7-[07]--+-00.0 | \-00.1 +-1f.0 +-1f.2 +-1f.3 +-1f.4 \-1f.6 01:00.0 VGA compatible controller: NVIDIA Corporation Device 1b80 (rev a1) 01:00.1 Audio device: NVIDIA Corporation Device 10f0 (rev a1) 03:00.0 VGA compatible controller: NVIDIA Corporation Device 1b80 (rev a1) 03:00.1 Audio device: NVIDIA Corporation Device 10f0 (rev a1) 05:00.0 VGA compatible controller: NVIDIA Corporation Device 1b80 (rev a1) 05:00.1 Audio device: NVIDIA Corporation Device 10f0 (rev a1) 07:00.0 VGA compatible controller: NVIDIA Corporation Device 1b80 (rev a1) 07:00.1 Audio device: NVIDIA Corporation Device 10f0 (rev a1) |