Libre Things

Some Thinkpads, like the T43, have several heat and fan problems.

On a default Linux installation, my T43 processor is at about 46°C, and the GPU at about 49°C, for an external temperature of 19°C.

The BIOS fan management algorithm is very bad. After a cold boot, the fan starts running non stop after a few minutes of use.

Fortunately, it is possible to use programs to take control of the fan in place of the BIOS.

To start, the thinkpad_acpi module must allows us to change the fan speed:

# vi /etc/modprobe.d/thinkpad.conf
options thinkpad_acpi fan_control=1 experimental=1

Your choice to reload the module or reboot your system.

# rmmod thinkpad_acpi
# modprobe thinkpad_acpi

Now you can take control of your fan:

# cat /proc/acpi/ibm/fan
# echo level 0 > /proc/acpi/ibm/fan
# echo level 7 > /proc/acpi/ibm/fan # full speed !!
# echo level auto > /proc/acpi/ibm/fan # back to normal, BIOS management

Now go here and copy the content of the script in /usr/local/bin/tp-fancontrol.

# mv index.php /usr/local/bin/tp-fancontrol
# chmod a+x /usr/local/bin/tp-fancontrol

Then, test the script:

# tp-fancontrol
# tp-fancontrol -s 5 # for a fan that starts later

In order to start the script at boot, we also fetch the tp-fancontrol.init.debian script on the same page. We add it at the system boot.

# mv index.php /etc/init.d/tp-fancontrol
# chmod a+x /etc/init.d/tp-fancontrol
# vi /etc/init.d/tp-fancontrol
DAEMON=/usr/sbin/fancontrol
# /etc/init.d/tp-fancontrol start
# /etc/init.d/tp-fancontrol stop
# update-rc.d tp-fancontrol defaults # note: only adding "start" scripts is also possible

The final touch is to edit the script to change the minimum fan triggering tresholds, so that the fan starts later when the system begins to heat:

# vi /usr/local/bin/tp-fancontrol
MIN_THRESH_SHIFT=5
INTERVAL=10 # you can also increase the speed update interval

A 5 seconds increase allows the fan to become quiet again when the computer activity is low.

References:

• http://www.thinkwiki.org/wiki/How_to_control_fan_speed
• http://www.thinkwiki.org/wiki/ACPI_fan_control_script
• http://www.thinkwiki.org/wiki/Problem_with_fan_noise