ASUS ROG Strix B850-E Gaming WIFI Motherboard M.2_3 slot speed is x2 instead of x4 ?

[SpeedTwelve]

Hello,

My ASUS ROG Strix B850-E Gaming WIFI Motherboard 's M.2_3 slot speed is x2 instead of x4; what can cause it?

When i plug Gen4x4 ssd it is working Gen4x2 and When i plug Gen3x4 ssd it is working Gen3x2

M.2_2 slot has no problem; it is working x4 ok.

Bios is 1006

CPU 7600X

Thank you.

[Jiaszzz_ROG]

Hello @SpeedTwelve 

Thank you for reaching out to us.
Could you please confirm whether this issue occurred on a newly purchased motherboard? May I ask how you verified the PCIe lane configuration, and have you updated the SSD drivers and firmware?
According to the ROG STRIX B850-E GAMING WIFI support page, the latest BIOS version 1022 was released on March 7, 2025. We recommend updating the BIOS and clearing CMOS before checking again.
If the issue persists, kindly provide the specs and models on the hardware components currently installed, along with screenshots of the SSD lane test results.

Thank you.

[SpeedTwelve]

My motherboard gone to RMA and money was refunded to me.