Ask me about my wife's perfect butthole
- Aug 28, 2019
No it gets limited by the per-lane throughput.You're confusing the interface with the disk. Plugging a 4.0 disk into a 3.0 slot doesn't make the disk itself run at half speed. It simply becomes limited by the older slot's throughput which is ~3.5GB/s on 3.0 and ~7GB/s on 4.0.
nVME drives use 4 lanes (generally, some server-class drives differ)... and a Gen 4 drive at ~7.5GB/second maxes out the per-lane throughput of PCIE 4.0, which is a little under 2GB/second.
If a Gen 5 drive goes for 2 lanes to reach 7.5GB/second speeds.. it wouldn't get those speeds on a Gen 4 slot.. as a Gen 4 slot can only run about ~1.9GB/second per lane.