Samsung Nvme 980 Pro SSD very slow on Windows 11

Does it still boot into Safe Mode? When entering Safe Mode, Windows should be able to automatically detect the VMD hardware [that you have re-enabled in BIOS] and reinstall the RST driver so that, next, you can boot into Windows normally again. Or choose to manually reinstall the RST driver in Safe Mode if necessary.
If, however, you can't boot into Safe Mode, then you can still try entering the Windows Recovery Environment (WinRE). Before you do this, start by entering bcdedit in an elevated command prompt and looking for the line with device:
Remember the number at the end.
Also note, even if you don't have a working WinRE available on the SSD, you can still get into WinRE by using a bootable USB flash drive that contains WinRE or something based on WinRE, like, e.g., the WinRE based bootable rescue media of Macrium Reflect or of Acronis True Image or, if you don't have any of these on hand, then just use the Windows Installation media (that you can create with the Media Creation Tool). You can press Shift + F10 at the main menu screen to get a command window as an administrator (i.e., an elevated command prompt). If using the Windows Installation media, you can press Shift + F10 when you get to the langage selection screen. Next, assuming your Windows folder is D:\Windows (note that the drive letters you get in WinRE may not necessarily be the same as the ones you got in Windows) you can run this:
bcdboot D:\Windows /s \Device\HarddiskVolume2 /f all (substitute the number at the end with the one that you found previously)
This should successfully copy the boot files from your Windows folder to your EFI partition. (You might need to temporarily disable Secure Boot in BIOS to get to where you want to be.) Boot into Safe Mode, and reboot normally again after that.

I have a Samsung PM9A1, the OEM version of the 980 pro and my experience with all the 22H2 versions… release, beta and dev channel is the Windows NVMe driver is much slower than Windows 22H1… about 10% slower. I’ve mentioned this to Microsoft, they don’t recognize benchmarks… so complain, complain, complain as there’s definitely a NVMe performance loss in Windows 22H2 with my Samsung PM9A1.

If I remember the Samsung NVMe Drivers had a flaw even in windows 10 especially the 980 series .
Games and other programs would not download or install on them correctly or crash while doing
The Fix Was using this command :
" REG ADD "HKLM\SYSTEM\CurrentControlSet\Services\stornvme\Parameters\Device" /v "ForcedPhysicalSectorSizeInBytes" /t REG_MULTI_SZ /d "* 4095" /f "
Similar thing is on This Article " Troubleshooting operating system disk sector size greater than 4 KB - SQL Server"
Some found a fix Running Apps in compatibility mode (set to Windows 7)
There was a fix update months later for win 10 and win 11 but it seems it did not work properly . So maybe the slowdown is somehow connected to this too.

I was running 22H2 Beta in August, I don’t remember the build number and the NVMe performance suddenly dropped. I went to the Dev channel hoping the performance would come back… and it did. A few builds latter and the Dev channel performance dropped too. Being frustrated, I decided to install Windows 11 22H1 and the performance was the best of the builds.
It seems Microsoft released KB5016629 build 22000.586 and that patch definitely boosted NVMe performance.
Looks like we’re going to need a patch for 22H2 as I can confidently say 22621 and above do suffer lower NVMe performance with my Samsung drives.

AlexDeLarge68 said:

But it's not possible to come back to Intel VMD, activating it in the BIOS and restart in safe mode (while this method worked passing to NVM Standard controller). The system doesn't find the drivers (and I didn't erase them), so the system doesn't boot up.
Any hint on how to reload the RST VMD drivers before booting the machine?

Click to expand...

I think the correct procedure to re-enable VMD should be in reverse order: from Safe Mode, force-install first from Device Manager the VMD device drivers, and THEN reboot and switch BIOS VMD on again. At this point the machine should be able to boot again in VMD correctly.

Remember: with VMD device drivers, NEVER thick also "□ Attempt to remove the driver for this device" when you uninstall them to try standard NVME Windows drivers! You must keep these drivers installed but unselected to be safe if you change your mind or the system won't find them automatically.

@hexaae
Are you aware that the last post within this thread is over 2 years old?

Yeah sorry for necroing but the problem with VMD/NVMe drivers is still present for many users in 2024. Can still be useful

hexaae said:

Yeah sorry for necroing but the problem is still present for many users in 2024.

Click to expand...

Why not open a brand spanking new shiny thread?

I understand many don't like necroing posts but... why having 120 threads about the same common issue instead of a useful single topic not wasting time searching around? Just my opinion

hexaae said:

I understand many don't like necroing posts but... why having 120 threads about the same common issue instead of a useful single topic not wasting time searching around? Just my opinion

Click to expand...

That is the role of moderators to bring those threads together in most cases.