Could you verify if adding two M.2 drives might affect your GPU PCIe lanes?
Could you verify if adding two M.2 drives might affect your GPU PCIe lanes?
I struggle with M.2 compatibility and how it affects GPU performance. I'm planning a new build and don't want extra cables. The motherboard (paired with a 13900k and 4090) has expansion slots that mention: "When M.2_1 is full, PCIEX16(G5) will run at x8." This suggests the closest slot to the CPU. I also heard it's better to place the OS drive there. This makes me think the GPU might slow down if I use it in that slot. The SSDs I have are a 980 PRO PCIe 4.0 NVMe 1TB and a 2TB version (same model, different size). I need to confirm which two M.2 slots are safe for these drives.
Yes, it's safe to use slot 1 for the OS drive and slow 2 for the rest.
A Gen 4 card in a Gen 5 slot will run at Gen 4 speed, which isn't a major issue. As I mentioned, it won't cause any significant changes. You'll have plenty of PCIe bandwidth available. The only GPU from the current Gen that can be impacted by X8 instead of X16 is the 4090, and the performance gap is around 1%.
I'm setting up a 4090 and wondering about the impact of using different bit depths. For Gen 4, swapping _1 with _2 or _3 might not change much, but if I can hit x16 speeds without losing M.2 performance, I'd go that way. With a Gen 5 M.2, I'd definitely stick with _1.