Actually PCIe specifically. NVMe improves performance slightly, but it's mostly all due to PCIe. I have a non-NVMe Samsung AHCI M.2 SSD from 2014 that gives me

Actually PCIe specifically. NVMe improves performance slightly, but it's mostly all due to PCIe. I have a non-NVMe Samsung AHCI M.2 SSD from 2014 that gives me ~2.3GB/s sequential reads and ~1.2GB/s sequential writes, no NVMe required.