Comment by adrian_b

I do not think that I have ever seen any benchmark for a PCIe 5.0 SSD that did not have sequential read speeds well over 10 GB/s.

If there were such a slow SSD, it would not make sense to buy it instead of a cheaper PCIe 4.0 SSD.

For PCIe 4.0 SSDs, I have seen a very large number of benchmarks where the SSDs achieved read speeds close to the theoretical limit, i.e. around 7 GB/s.

Searching now randomly for recent SSD reviews, I find many reviews for "SanDisk WD_BLACK SN8100", which achieve between 13 GB/s and 15 GB/s reading speed, which is better than most other consumer PCIe 5.0 SSDs.

Of course, if you write a very simple program that invokes something like "fread" or "read" in a loop, you will not reach such speeds. Achieving a SSD throughput close to the limit requires a more complex program that can ensure that the SSD controller is permanently busy with pipelined read commands.