Due to limited support for large queue depths and multiple workers, the full performance of NVMe SSDs could not be seen in Crystal Disk Mark 3.0.4 . For example, the maximum read bandwidth on this build for one NVMe drive was ~ 1.5 GB/s and the maximum IOPs was ~ 150K IOPs.
The developer has completed a new version, revision 4.0.3, that adds deeper queues and multiple worker threads to the benchmark and enables measurement of the true performance of an NVMe SSD. The same NVMe drive now measures over 2 GB/s for bandwidth and ~ 450K IOPs on random I/O. In order to fully saturate the NVMe drives, recommendations are a queue depth of at least 32 and a minimum of 8 worker threads for 4K random testing. Check it out at http://crystalmark.info/?lang=en.