I have a NUC (BEH model) and a M.2 SSD PCIe gen3 NMVe card (Samsung 970 pro 512GB) and I have a slow and fast write speed result in Ubuntu 18.04.3 with two different kernels. I used ukuu for kernel switching and in kernel 5.0+ which comes standard with the Ubuntu installer I get around 600MiB ( sad ) write speed and with a previous kernel version of 4.9.190, I get around 2200MiB with the benchmark tool in Ubuntu. I have tried the latest 5.2 kernel and it is still a problem. I have tried Linux mint 19.2 and I also get the a slow write speed because it is using a later kernel than 4.9.
Here is my benchmark result on kernel 4.9.190.
I think this and this are related problems and a simple google search indicates lots of SSD write performance issues. Could it be a massive potential linux kernel performance issue?
Any help or fix would be greatly welcome!