Upgraded to a B550 chipset and made some test with WD SN 750 Black after discovering here in the board the WD NVME driver (Thanks for that).
Tests done with Crystal Disk Mark 8.0.1, NVME settings
Before I used generic Intel RST driver 18.33.
My system: MSI B550M Mortar, 32 GB RAM, Ryzen 5 3600, WD SN 750, 1TB, FW 111110WD
First test carried out with AMD_StoreMI AHCI Driver v9.4.0.00036
Intel RST NVME Generic v18.33.0.1003, dated March 12, 2021, AMD_StoreMI
Western Digital NVME v3.3.2102.41615, dated February 16, 2021, AMD_StoreMI
Samsung NVMe driver v3.3.0.2003, dated January 21. 2020, AMD_StoreMI
Second test carried out with Microsoft Standard SATA AHCI Controller, v10.0.19041.906
Intel RST NVME Generic v18.33.0.1003, dated March 12, 2021, MS Standard AHCI
Western Digital NVME v3.3.2102.41615, dated February 16, 2021, MS Standard AHCI
Samsung NVMe driver v3.3.0.2003, dated January 21. 2020, MS Standard AHCI
From the values, the Samsumg is clear winner.
All NVME drivers performed better with Microsoft Standard AHCI Driver than with the AMD AHCI Driver.
Cheers
Tom