M2 Write Performance Problem?

[Guarateed_12]

First things first...
Build
Ausu TUF Gaming X570-Plus (Wi-Fi)
Ryzen 7 3700X
Corsair DDR4-3200 / 32Gb
C: Corsair Force MP600 M.2 1TB

It has been several months since I ran any SSD speed tests. Previous tests showed the drive to be behaving as expected i.e. 4900/4700 (MB/s). The other day I downloaded and ran PassMark and it gave me a rather unusual Write Speed result. On top of them not being what I had expected to see I'm also concerned about the disparity of these 2 benchmarks. I have also run CrystalDiskMark. CDM seems to fall off too when I run the test 6 times in a row. But as you can see the PassMark drop off at different times when the same test is run.

I have monitored the Drive temps with HWMonitor and there is nothing out of the ordinary with the temps. Is this just to be expected? I just can't account for the PassMark results dropping off at different times? The drive is only about at 25% full, so there is plenty of room to run these tests.

 

[arestavo]

At a WAG, the SLC cache gets exhausted and your speeds drop off of a cliff. Until the SLC cache offloads the data, speeds don't recover for the full amount of time that the first test could handle.

 

[mwroobel]

I addition, it is your boot drive and every other process is in contention with your benchmark program for drive access. This can cause significant dips in performance and uneven results, even pass to pass. Boot off a WInPE USB stick like Hiren's, run CrystalDiskMark and see if the problem resolves.