WD Black SN850X 2TB + Asrock Z790 = poor write performance

[BattleAngel_99]

Hello i’ve purchased a new 2TB SN850X as OS-drive for my system. I’ve cloned it from my previous 1TB SN850.
Any ideas why the write speed of the SN850X is too low?

Here’s a comparison of my M2-Drives:

SN850X

SN850

According to dashboard the 850X runs at PCIe4 x4:

I’ve tried the new PCIe5 socket, has same poor write performance.
My Windows11, drivers and bios are all up to date.

Do you have any idea why the SN850X write performance is too low? (even the old 970EVO beats the 850X)

[BattleAngel_99]

Here’s the result from my Samsung 970EVO and a screenshot from the Dashboard:

[Keerti_01]

Hi @BattleAngel_99,

Have you opened a Support Case? If not opened, for more information, please contact the WD Technical Support team for the best assistance and troubleshooting:
https://support-en.wd.com/app/ask

[BattleAngel_99]

Hello Keerti, thanks for your reply.
I will reinstall Windows 11 on the SN850X tomorrow to rule out that there may be an SSD alignment problem due to the cloning.

If my writing performance is still too low, I’ll open a ticket.

[BattleAngel_99]

The problem was actually caused by cloning!

After I reinstalled Windows 11, the write performance is fine.

SN-850X

VS:

SN-850