Question M.2 SSD is extremely slow in Gen4 slot ?

[Darkfade]

Hello, Ive recently built my system and Ive been experiencing extreme slow speeds through my gen4 pcie slot. Im getting 800-1000 mb/s compared to when I plug it in gen3 slot I get 3500mb/s

Please help, Ive been trying to fix this for the past 4hrs, I reinstalled windows, updated windows, checked for m2 firmware, reinstalled/reseated the m.2, made sure it was running in gen4 through bios, etc.

PC Specs
Mobo: MSI B550-A Pro
CPU: Ryzen 7 5800X
GPU RTX 4070 Ti Super
Storage: M.2 WD SN850X (bought new)
RAM: 16GB Corsair DDR4 3600
PSU: EVGA 750GQ 750w

 

[evermorex76]

Use Crystal DiskInfo to verify that the drive is running at PCIe4 x4 when in that slot, just as a baseline. Have you made sure the BIOS is up to date as well as the SSD firmware?

 

[Darkfade]

Use Crystal DiskInfo to verify that the drive is running at PCIe4 x4 when in that slot, just as a baseline. Have you made sure the BIOS is up to date as well as the SSD firmware?

Everything was updated, I checked its running on gen4

 

[Darkfade]

Use Crystal DiskInfo to verify that the drive is running at PCIe4 x4 when in that slot, just as a baseline. Have you made sure the BIOS is up to date as well as the SSD firmware?

https://imgur.com/a/pqLEF7P

View: https://imgur.com/a/pqLEF7P

 

[SkyNetRising]

I checked its running on gen4

Do you have M.2 heatsink installed?

 

[evermorex76]

Is the performance bad immediately or does it only happen while testing for a long period? Is it in benchmarks or something like Windows file transfers?

I have the same SSD and didn't really need a heatsink on it even when running benchmarks at max speed. I put one on it just for insurance but mainly just for fun. That board has a heatsink on the slot anyway. Keep DiskInfo open while running AS SSD or ATTO for a long period and see what the temps reach. Unless airflow is horrible in general in the case I wouldn't expect thermal throttling.