Discussing the application of PCIe 4 lanes alongside PCIe 3
Discussing the application of PCIe 4 lanes alongside PCIe 3
I own an Asrock X570 Steel with a Ryzen 3700 and 20 PCIe 4 lanes. Right now I run the Galax GTX 1660 Super, but I’m unsure how many lanes my new graphics card will consume. I plan to purchase an NVMe PCIe RAID card with four PCIe 3 lanes, which would total roughly 12-14 GB of bandwidth. If I connect four NVMe SSDs using those lanes, will I fill all PCIe lanes and cause a bottleneck between the GPU and storage?
These cards aren't ideal for am4 or 1200 because they require a full x16 slot, which isn't available in most setups. With a GPU, many slots won't function properly. It might be better to use fewer larger drives instead, as the performance gain on a desktop isn't worth it.
Your interpretation is mostly correct. In your setup, the PCIe RAID configuration would indeed use one x16 for a RAID device and two x8 lanes for the graphics card. This means the RAID would share the available bandwidth, which is limited by the slower link (x8). If the RAID demands 10 GBps while the GPU needs 4 GBps, the overall performance would be constrained to about 8 GBps due to the x8 bottleneck.
I don't respond unless I notice a reply and I'm ready to contribute.