mirror of
https://github.com/lm-sensors/lm-sensors.git
synced 2026-10-25 12:14:33 +00:00
Marius Reiner
0449274597
git-svn-id: http://lm-sensors.org/svn/lm-sensors/trunk@2008 7894878c-1315-0410-8ee3-d5d059ff63e0
96 lines
3.8 KiB
Plaintext
96 lines
3.8 KiB
Plaintext
|
|
fancontrol - automated software based fan speed regulation
|
|
|
|
|
|
Introduction
|
|
|
|
fancontrol is a shellscript for use with lm_sensors. It reads its
|
|
configuration from a file, then calculates fan speeds from temperatures and
|
|
sets the corresponding pwm outputs to the computed values. It is included in
|
|
lm_sensors since 2.8.0, the latest version is always available through CVS or
|
|
at http://www.hdev.de/fancontrol/ For easy configuration, there's a script
|
|
named pwmconfig which lets you interactively write your configuration file for
|
|
fancontrol. Alternatively you can write this file yourself using the
|
|
information from the configuration section of this document.
|
|
|
|
Please be careful when using the fan control features of your mainboard, in
|
|
addition to the risk of burning your CPU, at higher temperatures there will be
|
|
a higher wearout of your other hardware components, too. So if you plan to use
|
|
these components in 50 years, _maybe_ you shouldn't use fancontrol/your
|
|
hardware at all. Also please keep in mind most fans aren't designed to be
|
|
powered by a PWMed voltage, for more detailed information on this I recommend
|
|
this appnote: http://www.maxim-ic.com/appnotes.cfm/appnote_number/707
|
|
In practice it doesn't seem to be a major issue, the fans will get slightly
|
|
warmer, just be sure to have a temperature alarm and/or shutdown call, in case
|
|
some fan fails, because you probably won't hear it anymore ;)
|
|
|
|
Configuration
|
|
|
|
Since most of you are going to use the prog/pwm/pwmconfig script, the config
|
|
file syntax will be discussed last. First I'm going to describe the various
|
|
variables available for changing fancontrol's behaviour:
|
|
|
|
INTERVAL
|
|
This variable defines at which interval in seconds the main loop of
|
|
fancontrol will be executed
|
|
|
|
FCTEMPS
|
|
Maps pwm outputs to temperature sensors so fancontrol know which
|
|
temperature sensors should be used for calculation of new values for
|
|
the corresponding pwm outputs.
|
|
|
|
MINTEMP
|
|
The temperature at which the fan gets switched off completely.
|
|
|
|
MAXTEMP
|
|
The temperature at which the fan gets switched to full speed.
|
|
|
|
MINSTART
|
|
Sets the minimum speed at which the fan begins spinning. You should
|
|
use a safe value to be sure it works, even when the fan gets old.
|
|
|
|
MINSTOP
|
|
The minimum speed at which the fan still spins. Use a save value here,
|
|
too.
|
|
|
|
If you set up your configuration by hand, be sure to include ALL variables and
|
|
use valid values, there's no error handling yet! The file format is a bit
|
|
strange:
|
|
|
|
VARIABLE=chip/pwmdev=value chip/pwmdev2=value2 [...] VARIABLE2=[...]
|
|
|
|
Each variable has its own line. The variable name is followed by an equal sign
|
|
and the device=value pairs. These consist of the relative path to the pwm
|
|
output (from /proc/sys/dev/sensors/) for which the value is valid, equal sign
|
|
followed by the value and are seperated by a blank.
|
|
|
|
Example:
|
|
|
|
MINTEMP=w83627hf-isa-0290/pwm2=40 w83627hf-isa-0290/pwm1=54
|
|
|
|
You have to play with the temperature values a bit to get happy. For initial
|
|
setup I recommend using the pwmconfig script. Small changes can be made by
|
|
editing the config file directly following the rules above.
|
|
|
|
|
|
The algorithm
|
|
|
|
fancontrol first reads its configuration, writes it to arrays and loops its
|
|
main function. This function gets the temperatures and fanspeeds from
|
|
lm_sensors proc files and calculates new speeds depending on temperature
|
|
changes, but only if the temp is between MINTEMP and MAXTEMP. After that, the
|
|
new values are written to the pwm outputs. Currently the speed increases
|
|
quadratically with rising temperature. This way you won't hear your fans most
|
|
of the time at best.
|
|
|
|
|
|
Planned features
|
|
|
|
rc-scripts for some gnu/linux-distributions
|
|
smoother regulation (temp interpolation)
|
|
other curve styles (linear, exponential)
|
|
gui for configuration
|
|
|
|
If you have other wishes or want to contribute something, please let me know:
|
|
marius.reiner${AT}hdev.de
|