many NVMe drives on the market are useless jokes. try some from the now biggest semiconductor company, test their fsync() performance and don't get a heart attack for seeing those ugly numbers. ;)
hi olavgg, I was searching for fast fsync & low cost NVMe SSD a few months ago, so I looked into consumer NVMe SSDs. Samsung 960 Pro was the first I tested, the results were just shockingly bad. It was so bad to the extent that I started to question whether my kernel/installation caused the slowness issue. Searched online and found a few of your posts talking about the exact same problem you saw. That saved me quite a bit time. :)
Yes, totally agree with the conclusion in your link above, consumer SSD (NVMe or not, high end or cheap) doesn't worth a dime. Cheers!
Summary performance comparison by Storage Class: http://xitore.com/what-is-nvm-x
EDIT, added source: [1] http://www.diablo-technologies.com/memory1/