Install PCIe cards in your Mac Pro

You'll be able to do more with less in this case, since a PCIe x8 slot can handle almost exactly what a PCIe x16 slot can currently

I believe both slots are generation 3 because chapter 1 of the manual indicates that HP only offered Gen 3 NVMe SSD's in the model series and

m2 slot 2 NVMe SSDs are backward-compatible, so even with a Gen3 platform, you usually get better value from a Gen4 SSD even if it can't run at its rated speed

m2 slot types I know I'm replying to an old comment, but maybe someone else sees this I recently got a Gen 4 SSD while still having a Gen 3 motherboard