Hey everyone! I'm currently using an RTX 5090 and I'm considering adding another GPU for some local LLM model training while still being able to game. I'm running this on an Asus B860M Max Gaming AX motherboard, which isn't the best out there. I'm curious if I can set it up with two GPUs, and I'm okay with running one at 8x PCI 4.0 if needed. Would that work, or should I rethink my setup?
1 Answer
You've got one full bandwidth PCIe 5.0 slot on that board, but adding another GPU to any other slot won't give you the best performance. It's not ideal since it will run slower and you likely won't get your money's worth. If you're considering a setup with dual GPUs, you'd be better off upgrading to a Z890 motherboard that has a second PCIe 4.0 x16 slot. But even then, your second RTX 5090 would be limited to half the bandwidth, so keep that in mind. Plus, the 285k processor only has 24 PCIe lanes, which can't handle dual PCIe 5.0 x16 slots, unfortunately. Also, micro ATX boards usually don't have the space necessary for a second GPU.
Yeah, ideally you'd run a PCIe 5.0 x8 and a PCIe 4.0 x16. That setup would be decent bandwidth-wise, but like you mentioned, space is a real issue!