Low chassis fan speed with ASUS ROG STRIX X870E-E GAMING WIFI, BIOS 1605

[Migz-DH]

Hello!

I use two 200mm case fans that are supposed to run at 700 rpm, but using the ASUS ROG STRIX X870E-E GAMING WIFI motherboard with BIOS 1605 at full speed in the BIOS, the fans only run at 530-565 rpm. The fan that is in the 530s is attached to the CPU fan slot at full speed, and the fan that is in the 560s in the Chassis fan 5 slot at full speed.

I would like to get the fans to rotate at their rated max speed. Does anyone have any advice on how to solve this particular issue?

Thank you!!

[Migz-DH]

With BIOS 1715, released on 25 Sept 2025, these two chassis fans still do not run at full rated speed even when set to full speed.

Interestingly, before writing this update, I checked the RPMs in the BIOS, and they both started out in the 200s before slowly increasing over the course of a couple of minutes. They behave as though they are running on a temp curve algorithm but tied to a different temperature than the CPU. CPU and Chassis 5 fans.