Quiet fans on Thinkpad P15

Intro

The Thinkpad P15 laptop is a nice linux machine, but there is an annoying detail, as Arch wiki writes: “The default operation of fans is noisy, as they are basically at medium power all the time. The thinkfan program can be used to create a quieter operation, while retaining reasonable temperatures.” . Let’s make it quieter.

Prerequisite

Install thinkfan rpm package and enable the daemon:

# zypper in thinkfan && systemctl enable --now thinkfan

Make sure modules are loaded at startup with the options to override fan control and enable experimental features:

$ cat /etc/modules-load.d/thinkpad.conf
thinkpad_acpi
coretemp

$ cat /etc/modprobe.d/thinkpad_acpi.conf
options thinkpad_acpi fan_control=1 experimental=1

Configuration

The daemon configuration consists in a single and short file. On the first part we need to specify the virtual file containing the temperatures; then the file which controls the fan speed, and a third section wich maps the fan level to the temperature range:

$ cat /etc/thinkfan.conf 
sensors:
  - tpacpi: /proc/acpi/ibm/thermal
    # Some of the temperature entries in /proc/acpi/ibm/thermal may be
    # irrelevant or unused, so individual ones can be selected:
    indices: [1, 2, 4, 5, 6]

fans:
  - tpacpi: /proc/acpi/ibm/fan

levels:
  - [0, 0, 60]
  - [2, 60, 65]
  - [3, 65, 70]
  - [5, 70, 75]
  - [6, 75, 80]
  - [7, 80, 85]
  - ["level disengaged", 85, 255]

Conclusion

Depending on your system, you can use many other programs to control fan speed in linux; thinkfan has the advantage to be lightweight and very configurable.