Last year I built an AM5 PC with x670e board and installed 2x gen4 ssds and 1 gen3 from different OEMs.
Today I installed another gen4 and ran benchmark on all drives. To my surprise all the old ssds read speed is down by 30-60% from last result, write speed is similar to specs. I am unable to figure out what is wrong with them all drives are showing 98-99% of spare.
So there are 28x PCIe Gen 5 (24 usable) 16 lanes for GPU, 4 for m.2 and 4 shared with chipset
Additionally 12x PCIe gen4 and 4 Gen3 lanes.
All ssds are running in x4 mode