If you want to quickly test your disk speed on Linux (might work on macOS, but not 100% sure) simply do:
sudo dd if=/dev/zero of=test bs=1G count=7 status=progress ; rm -f test
Decently happy with my results: 7516192768 bytes (7.5 GB, 7.0 GiB) copied, 5.10763 s, 1.5 GB/s. I figure, though, that’s expected on an NVMe M.2 SSD.