My last one was a ROMED8-2T from Asrock Rack. They have a catalog with standard and also weird motherboards(mine came with 7 PCIev4 slots because it's a GPU ser

My last one was a ROMED8-2T from Asrock Rack. They have a catalog with standard and also weird motherboards(mine came with 7 PCIev4 slots because it's a GPU server, and 6 of them had dedicated lanes to the CPU. Most motherboards try to share bandwidth with a PCIe switch, so not ideal for machine learning) A quick search shows 2 Intel motherboards with mini-ITX form. There was also a micro-ATX. https://download.asrock.com/Download/e-catalog/ASRockRackProductGuide.pdf https://download.asrock.com/Download/e-catalog/ASRockRackPro... I've also bought from Gigabyte before. The selection isn't as good, but I see an AMD and 3 Intel with mini-ITX. You might have to get separate embedded versions of the processors. https://www.gigabyte.com/Enterprise/Server-Motherboard https://www.gigabyte.com/Enterprise/Server-Motherboard I think Intel has more options with smaller boards here. Always check the block diagram to see if the IO matches how you'll use it.