The ATTO Disk Benchmark measures storage systems performance with various transfer sizes and test lengths for reads and writes. The benchmark performs file transfers ranging from 0.5 KB to 8192 KB. ATTO can be adjusted to do overlapped I/O, in a variety of queue depths. The test was run with the default runs of 0.5KB through 8MB transfer sizes with the total length being 256MB and QD4. ATTO probably gives the most accurate results for compressible read and write data:

The Adata XPG SX800 480GB SSD takes the overall win in the read test. The Crucial P1 has lower read performance from all the rest NVMe SSDs in the test, although the drive's read and write throughput are more than three times faster than SATA-based SSDs:

In the write part, the Crucial P1SSD showed a solid overall performance, slightly slower than the Adata XPG SX800's.