Motherboards controlling fan speeds
Motherboards controlling fan speeds
I was reviewing the BIOS settings (UEFI included) and observed the fan RPM displays fluctuating slightly, likely linked to the 4-pin PWM CPU cooler. This behavior aligns with how such a cooler operates. The presence of a system fan header without any connection suggests it might be showing estimated speeds based on PWM signals from the motherboard. The CPU cooler fan indeed increases speed during higher loads, so PWM is functioning properly. References exist for no actual fan speed readings and unrealistic speeds when the fan is idle, but not for empty headers. I considered adjusting the fan speed manually to see its effect, though that setting isn't accessible on this board. Have others noticed similar patterns?
Back in the early days, I noticed prebuilt units with dual pin fans. They only received power and ground from the motherboard. The fan curve and RPMs aren’t important if most users never interact with it, and the company seems to benefit from adding an extra dollar per motherboard. I think the same idea likely works for HP as well.
They made several noteworthy selections, though... I’ve removed the fan and reinstalled it, confirming it’s a 4-pin PWM unit. I also changed the temperature setting to another model, which performed well. The speed clearly changes, and using a 3-pin fan would run at full capacity, indicating PWM control is in use. Edited April 1, 2024 by JosephKnowsNot attempting to sound overly friendly.