ssd passthrough to vm error random performance

[tsunheiat]

i passthrough ssd to vm using the pcie driver and get random performance very low form benchmark tools crystaldiskmark and as-ssd. Both benchmark result show have a random performance decrease. 

my motherboard is asus x570 prime pro

my ssd is KIOXIA CD6 3.84TB (KCD61LUL3T84) that is but from old market, have about 1.5pb write, it is still a lot life from the Reliability (1DWPD for 5 years) and it also normally testing in phy win. 

The win is testing with Windows 21h2 form microsoft maker.

The ssd is put in the first pcie x16 with a pcie> 2 u2, the ssd is working on pcie 4.0x4, that show in the CrystalDiskInfo in all situation.

I am using 5900x

I found that when testing ran 4k q512 t16 is using 60% cpu+ 
Then I saw that my cpu is working in little low mhz for about 100 compare with phy win, i tried to use amd pbo2 (orginal using pbo=enable)

When testing the ssd it is show temp is <50, i also use hwinfo it showed only one sensor.

https://docs.google.com/spreadsheets/d/1aS5_4I1a47NZyUmN7pgi627YWTG2BJD940aiQ68rHLE/edit#gid=0

This is my testing data, ubunut is ubuntu20. 

The linux benchmark is using project from github https://github.com/masonr/yet-another-bench-script 

curl -sL yabs.sh | bash -s -- -ig

I hope that to solve this problem of know what going on, this ssd i want to use for hyper-v vm use, that vm need random performance.
Already testing at pve vm is much normally. but i would not want to change my host system as it cannot make uefi vm using hyper-v.

If there is any information that can help, I need how to do, as I just have little linux knowledge . I have tried for few days and still can't find what is the problem.

Edited February 12, 2022 by tsunheiat