What is my best option for adding a second GPU?

A user on the Level1Techs forum asks for advice on adding a second Nvidia GeForce RTX 5060 Ti GPU to an Asus TUF-GAMING B550M Plus motherboard for local large language model inference, citing physical and bandwidth constraints. The user's system has a single PCIe 4.0 x16 slot, a second PCIe 3.0 x16 slot on chipset lanes, and a PCIe 4.0 x4 M.2 slot, but the 5060 Ti is an 8x card with a 16x connector, causing issues with M.2 to PCIe adapters. The user seeks budget-friendly options such as a new motherboard and case, Oculink, or a different GPU.

Hi all, first post on L1 so apologies if it’s in the wrong subforum. I have a mATX PC with a single 5060Ti, and I’d like to add a second one. My intended use is for local LLM inference with a single model split over two GPUs. I’ve been exploring as many options as I can but keep running into roadblocks. Here are my limitations: - Another GPU won’t fit in the case, nor into the second 16x slot of the motherboard. - My mobo, Asus TUF-GAMING B550M Plus, only has a single PCI-E 4.0 16x slot, which doesn’t support 8x/8x bifurcation in the BIOS . The second 16x slot is 3.0, on chipset lanes, and I’ve ruled that out for bandwidth/latency reasons with LLM model splitting. - The mobo has a PCI-E 4.0 4x M.2 NVME slot on CPU lanes, but apparently the 5060ti doesn’t work well with m2 to pci-e extenders like ADT-Link’s K43SG because of … retiming issues? Given that the 5060ti is actually an 8x card with a 16x connector. 1 https://egpu.io/forums/expresscard-mpcie-m-2-adapters/need-help-with-adt-link-k43sg-egpu-rtx-5060-ti-not-detected-on-m-2-gen-4-slot-works-on-gen-3/ 2 https://egpu.io/forums/wip-builds/k43sg-5060-ti-gmktec-nucbox-m5-plus-stuck-at-gen-3-0-x2-when-3-0-x4-is-possible/ - Have a 550W Corsair PSU and Ryzen 5600X CPU at stock clocks/voltage. Happy to power-limit the GPU/s to 150W if that makes ‘em fit within the PSU’s operating capacity, or add a second PSU eg Dell DA2 . - Trying to do this in a budget friendly way I’d love some advice on what my best options are. Buy a new mobo and case? Try to do something with Oculink instead? Consider a different GPU? Any other routes I haven’t considered? Thanks everyone. The Asus manual says the PCI16X 1 slot “Support PCIe bifurcation for RAID on CPU function.” implying that you can run 4 m2 SSDs into the main 16x slot with a 4x/4x/4x/4x splitter card. I can’t tell if that would work with an M2 to PCI-E splitter of some kind.