Fan control scripts
This page provides several scripts for controlling the ThinkPad's system fan according the its thermal sensors (overriding the embedded controller), in order to reduce fan noise and decrease power consumption.
ATTENTION!
These scripts relies on undocumented hardware features and overrides nominal hardware behavior. It may thus cause arbitrary damage to your laptop or data. Watch your temperatures!
Contents
Variable speed control scripts
The following scripts sets the fan speed according to the system's thermal sensors. In addition, they include a hack for preventing the annoying fan pulsing that occurs on some systems. Note that the fan levels, thresholds and anti-pulsing hacks are system-specific, so you may need to adjust them.
bash script with fine control over fan speed
The following requires only ibm-acpi 0.11 or higher (e.g., as found in kernel 2.6.14 and higher) with the experimental=1 module parameter. It supports (optional) daemon mode and logging to syslog.
This scripts uses a different temperature range for each sensor, since they have different specs and thermal systems. For each sensor, a fan level is chosen based on the minimum and maximum temperatures configured for that sensor; then the actual fan level is set to the slowest that will satisfy all sensors. There are also some hysteresis features - see the script for the details. The method of controlling fan speed is documented here.
Current options:
Usage: ./tp-fancontrol [OPTION]...
Available options:
-s N shift up temperature thresholds by N degrees
(positive for quieter, negative for cooler)
-t test mode
-q quiet mode
-d daemon mode, go into background (implies -q)
-l log to syslog
-k kill daemon (ignores all but -p)
-p pid file location for daemon mode, default: /var/run/tp-fancontrol.pid
ATTENTION!
The list of temperature ranges used below is much more liberal than the rules used by the embedded controller firmware, and is derived mostly from anecdotal evidence, hunches and wishful thinking. It is also model-specific - see thermal sensors.
With no further ado, here is the script:
#!/bin/bash
# tp-fancontrol 0.2.4 (http://thinkwiki.org/wiki/ACPI_fan_control_script)
# Provided under the GNU General Public License version 2 or later or
# the GNU Free Documentation License version 1.2 or later, at your option.
# See http://www.gnu.org/copyleft/gpl.html for the Warranty Disclaimer.
# This script dynamically controls fan speed on some ThinkPad models
# according to user-defined temperature thresholds. It implements its
# own decision algorithm, overriding the ThinkPad embedded
# controller. It also implements a workaround for the fan noise pulse
# experienced every few seconds on some ThinkPads.
#
# Run 'tp-fancontrol --help' for options.
#
# WARNING: This script relies on undocumented hardware features and
# overrides nominal hardware behavior. It may thus cause arbitrary
# damage to your laptop or data. Watch your temperatures!
#
# WARNING: The list of temperature ranges used below is much more liberal
# than the rules used by the embedded controller firmware, and is
# derived mostly from anecdotal evidence, hunches and wishful thinking.
# It is also model-specific.
# Temperature ranges, per sensor:
# (min temperature: when to step up from 0-th fan level,
# max temperature: when to step up to maximum fan level)
THRESHOLDS=( # Sensor ThinkPad model
# R51 T41/2 Z60t 43-26xx
# min max # ---------- ------- ----- ----- ---------------------------
50 70 # EC 0x78 CPU CPU ? CPU
47 60 # EC 0x79 miniPCI ? HDAPS HDAPS, through EC
43 55 # EC 0x7A HDD ? ? ?
49 68 # EC 0x7B GPU GPU ? GPU
40 50 # EC 0x7C BAT BAT BAT BAT (front left of battery)
45 55 # EC 0x7D n/a n/a n/a n/a
37 47 # EC 0x7E BAT BAT BAT BAT (rear right of battery)
45 55 # EC 0x7F n/a n/a n/a n/a
45 55 # EC 0xC0 ? n/a ? ?
48 60 # EC 0xC1 ? n/a ? Southbridge under miniPCI?
50 65 # EC 0xC2 ? n/a ? Power circuitry (under CDC)
47 60 # HDAPS HDAPS HDAPS HDAPS HDAPS, direct access
)
# On T43, the HDAPS sensor under center left edge of miniPCI (top left of touchpad)
# On Z60t, it is on the bottom of the motherboard next to the port replicator port.
LEVELS=( 0 2 4 7) # Fan speed levels
ANTIPULSE=( 0 1 0 0) # Prevent fan pulsing noise at this level
# (reduces frequency of fan RPM updates)
OFF_THRESH_DELTA=3 # when gets this much cooler than 'min' above, may turn off fan
MIN_THRESH_SHIFT=0 # increase min thresholds by this much
MIN_WAIT=120 # minimum time (seconds) to spend in a given level before stepping down
IBM_ACPI=/proc/acpi/ibm
HDAPS_TEMP=/sys/bus/platform/drivers/hdaps/hdaps/temp1
LOGGER=/usr/bin/logger
INTERVAL=3
SETTLE_TIME=6
RESETTLE_TIME=300
PID_FILE=/var/run/tp-fancontrol.pid
VERBOSE=true
DRY_RUN=false
DAEMONIZE=false
AM_DAEMON=false
KILL_DAEMON=false
SYSLOG=false
usage() {
echo "
Usage: $0 [OPTION]...
Available options:
-s N shift up temperature thresholds by N degrees
(positive for quieter, negative for cooler)
-t test mode
-q quiet mode
-d daemon mode, go into background (implies -q)
-l log to syslog
-k kill daemon (ignores all but -p)
-p pid file location for daemon mode, default: $PID_FILE
"
exit 1;
}
while getopts 's:qtdlp:kh' OPT; do
case "$OPT" in
s) # shift thresholds
MIN_THRESH_SHIFT="$OPTARG"
;;
t) # test mode
DRY_RUN=true
;;
q) # quiet mode
VERBOSE=false
;;
d) # go into background and daemonize
DAEMONIZE=true
;;
l) # log to syslog
SYSLOG=true
;;
p) # different pidfile
PID_FILE="$OPTARG"
;;
k) # kill daemon
KILL_DAEMON=true
;;
h) # short help
usage
;;
\?) # error
usage
;;
esac
done
[ $OPTIND -gt $# ] || usage # no non-option args
# no logger found, no syslog capabilities
$SYSLOG && [ ! -x $LOGGER ] && SYSLOG=false
if $DRY_RUN; then
echo "$0: Dry run, will not change fan state."
VERBOSE=true
DAEMONIZE=false
fi
thermometer() { # output list of temperatures
# Base temperatures from ibm-acpi:
[ -r $IBM_ACPI/thermal ] || { echo "$0: Cannot read $IBM_ACPI/thermal" 2>&1 ; exit 1; }
read X Y < $IBM_ACPI/thermal
[ "$X" == "temperatures:" ] || { echo "$0: Bad temperatures: $X $Y" >&2; exit 1; }
echo -n "$Y ";
# Extended temperatures at EC offsets 0xC0 to 0xC2:
[ -r $IBM_ACPI/ecdump ] || { echo "$0: Cannot read $IBM_ACPI/ecdump" 2>&1; exit 1; }
perl -e 'm/^EC 0xc0: .(..) .(..) .(..) / and print hex($1)." ".hex($2)." ".hex($3)." " and exit 0 while <>; exit 1' < $IBM_ACPI/ecdump
# HDAPS temperature (optional):
[ -r $HDAPS_TEMP ] && echo -n "`cat $HDAPS_TEMP` "
return 0
}
speedometer() { # output fan speed RPM
sed -n 's/^speed:[ \t]*//p' $IBM_ACPI/fan
}
setlevel() { # set fan speed level
$DRY_RUN || echo 0x2F $1 > $IBM_ACPI/ecdump
}
getlevel() { # get fan speed level
perl -e 'm/^EC 0x20: .* (..)$/ and print $1 and exit 0 while <>; exit 1' < $IBM_ACPI/ecdump
}
cleanup() { # clean up after work
$AM_DAEMON && rm -f "$PID_FILE" 2> /dev/null
$SYSLOG && $LOGGER -t "`basename $0`[$$]" \
"Shutting down, switching to automatic fan control"
$DRY_RUN || echo enable > $IBM_ACPI/fan
}
floor_div() {
echo $(( (($1)+1000*($2))/($2) - 1000 ))
}
control_fan() {
# Enable the fan in default mode if anything goes wrong:
set -e -E -u
trap "cleanup; exit 2" HUP INT ABRT QUIT SEGV TERM
trap "cleanup" EXIT
IDX=0
START_TIME=0
MAX_IDX=$(( ${#LEVELS[@]} - 1 ))
SETTLE_LEFT=0
RESETTLE_LEFT=0
FIRST=true
$SYSLOG && $LOGGER -t "`basename $0`[$$]" "Starting dynamic fan control"
# Control loop:
while true; do
TEMPS=`thermometer`
$VERBOSE && SPEED=`speedometer`
$VERBOSE && ECLEVEL=`getlevel`
NOW=`date +%s`
# Calculate new level index by placing temperatures into Z-regions:
# Z >= 2*I means "must be at index I or higher"
# Z = 2*I+1 is hysteresis: "don't step down if currently at I+1"
# hence the Z-regions are, for d=(MAX-MIN)/(2*MAX_IDX-1) :
# Z=0:{-infty..MIN-d) Z=1:{MIN-d..MIN) Z=2:{MIN..MIN+d} Z=3:{MIN+d..MIN+2d} ... Z=2*MAX_IDX:{MAX-d, MAX}
MAX_Z=$(( IDX>0 ? ( NOW>START_TIME+MIN_WAIT ? 2*(IDX-1) : 2*IDX ) : 0 ))
SENSOR=0
Z_STR="$MAX_Z+"
TEMP_STR="";
for TEMP in $TEMPS; do
[ $((2*SENSOR+2)) -le ${#THRESHOLDS[@]} ] ||
{ echo "Too many sensors, not enough values in THRESHOLDS" 2>&1; exit 1; }
if [ $TEMP == -128 ]; then
Z='_'; TEMP='_' # inactive sensor
else
MIN=$((THRESHOLDS[SENSOR*2] + MIN_THRESH_SHIFT));
MAX=$((THRESHOLDS[SENSOR*2+1]))
if (( TEMP < MIN - OFF_THRESH_DELTA )); then
Z=0
else
Z=$(( `floor_div $(( (TEMP-MIN)*(2*MAX_IDX-2) )) $((MAX-MIN))` + 2 ))
fi
[ $MAX_Z -gt $Z ] || MAX_Z=$Z
fi
Z_STR="${Z_STR}${Z}"
TEMP_STR="${TEMP_STR}${TEMP} "
(( ++SENSOR ))
done
[ $SENSOR -gt 0 ] || { echo "No temperatures read" >&2; exit 1; }
(( (MAX_Z == 2*IDX-1) && ++MAX_Z )) # hysteresis
NEW_IDX=$(( MAX_Z/2 ))
[ $NEW_IDX -le $MAX_IDX ] || NEW_IDX=$MAX_IDX
# Transition
$FIRST && OLDLEVEL='?' || OLDLEVEL=${LEVELS[$IDX]}
NEWLEVEL=${LEVELS[$NEW_IDX]}
$VERBOSE && echo "L=$OLDLEVEL->$NEWLEVEL EC=$ECLEVEL RPM=`printf %4s $SPEED` T=($TEMP_STR) Z=$Z_STR"
if [ $OLDLEVEL != $NEWLEVEL ]; then
START_TIME=$NOW
$SYSLOG && $LOGGER -t "`basename $0`[$$]" "Changing fan level: $OLDLEVEL->$NEWLEVEL"
fi
setlevel $NEWLEVEL
sleep $INTERVAL
# If needed, apply anti-pulsing hack after a settle-down period (and occasionally re-settle):
if [ ${ANTIPULSE[${NEW_IDX}]} == 1 ]; then
if [ $NEWLEVEL != $OLDLEVEL -o $RESETTLE_LEFT -le 0 ]; then # start settling?
SETTLE_LEFT=$SETTLE_TIME
RESETTLE_LEFT=$RESETTLE_TIME
fi
if [ $SETTLE_LEFT -ge 0 ]; then
SETTLE_LEFT=$((SETTLE_LEFT-INTERVAL))
else
setlevel 0x40 # disengage briefly to fool embedded controller
sleep 0.5
RESETTLE_LEFT=$((RESETTLE_LEFT-INTERVAL))
fi
fi
IDX=$NEW_IDX
FIRST=false
done
}
if $KILL_DAEMON ; then
if [ -f "$PID_FILE" ]; then
set -e
DPID="`cat \"$PID_FILE\"`"
kill "$DPID"
rm "$PID_FILE"
$VERBOSE && echo "Killed process $DPID"
else
$VERBOSE && echo "Daemon not running."
exit 1
fi
elif $DAEMONIZE ; then
if [ -e "$PID_FILE" ]; then
echo "$0: File $PID_FILE already exists, refusing to run."
exit 1
else
AM_DAEMON=true VERBOSE=false control_fan 0<&- 1>&- 2>&- &
echo $! > "$PID_FILE"
exit 0
fi
else
[ -e "$PID_FILE" ] && echo "WARNING: daemon already running"
control_fan
fi
The authors of the script (Thinker and Spiney) disclaim all warranty for this script, and makes it available the terms of the GPL version 2 or later, or at your option, the GFDL.
bash script with fine control over fan speed (requires kernel patch)
The following is a simpler patch (without extra features like daemon mode and logging). It requires the patch for controlling fan speed.
#!/bin/bash
# This script dynamically controls fan speed on some ThinkPad models
# according to user-defined temperature thresholds. It implements its
# own decision algorithm, overriding the ThinkPad embedded
# controller. It also implements a workaround for the fan noise pulse
# experienced every few seconds on some ThinkPads.
#
# The script requires the ibm_acpi patch at
# http://thinkwiki.org/wiki/Patch_for_controlling_fan_speed
#
# WARNING: This script relies on undocumented hardware features and
# overrides nominal hardware behavior. It may thus cause arbitrary
# damage to your laptop or data. Watch your temperatures!
#
# This file is placed in the public domain and may be freely distributed.
LEVELS=( 0 2 4 7) # Fan speed levels
UP_TEMPS=( 52 60 68 ) # Speed increase trip points
DOWN_TEMPS=( 48 56 64 ) # Speed decrease trip points
ANTIPULSE=( 0 1 0 0) # Prevent fan pulsing noise at this level
# (this also prevents fan speed updates)
IBM_ACPI=/proc/acpi/ibm
FAN=$IBM_ACPI/fan
INTERVAL=3
VERBOSE=true
DRY_RUN=false
[[ "$1" == "-t" ]] && { DRY_RUN=true; echo "$0: Dry run, will not change fan state."; }
# Enable the fan in default mode if anything goes wrong:
set -e -E -u
$DRY_RUN || trap "echo enable > $FAN; exit 0" EXIT HUP INT ABRT QUIT SEGV TERM
thermometer() { # output list of temperatures
read X Y < $IBM_ACPI/thermal
[[ "$X" == "temperatures:" ]] || {
echo "$0: Bad temperatures: $X $Y" >&2
exit 1
}
echo "$Y";
}
speedometer() { # output fan speed
cat $FAN | sed '/^speed/!d; s/speed:[ \t]*//'
}
IDX=0
MAX_IDX=$(( ${#LEVELS[@]} - 1 ))
SETTLE=0
while true; do
TEMPS=`thermometer`
$VERBOSE && SPEED=`speedometer`
# Calculate new level
NEWIDX=$IDX
DOWN=$(( IDX > 0 ))
for TEMP in $TEMPS; do
# Increase speed as much as needed
while [[ $NEWIDX -lt $MAX_IDX ]] &&
[[ $TEMP -ge ${UP_TEMPS[$NEWIDX]} ]]; do
(( NEWIDX ++ ))
DOWN=0
done
# Allow decrease (by one index)?
if [[ $DOWN == 1 ]] &&
[[ $TEMP -gt ${DOWN_TEMPS[$(( IDX - 1 ))]} ]]; then
DOWN=0
fi
done
if [[ $DOWN == 1 ]]; then
NEWIDX=$(( IDX - 1 ))
fi
# Transition
OLDLEVEL=${LEVELS[$IDX]}
NEWLEVEL=${LEVELS[$NEWIDX]}
$VERBOSE && echo "tpfan: Temps: $TEMPS Fan: $SPEED Level: $OLDLEVEL->$NEWLEVEL"
$DRY_RUN || echo level $NEWLEVEL > $FAN
sleep $INTERVAL
# If needed, apply anti-pulsing hack after a settle-down period:
if [[ ${ANTIPULSE[${NEWIDX}]} == 1 ]]; then
if [[ $NEWLEVEL == $OLDLEVEL ]]; then
if [[ $SETTLE -ge 0 ]]; then
(( SETTLE -= INTERVAL ))
else
$DRY_RUN || echo level disengaged >> $FAN
sleep 0.5
fi
else
SETTLE=6
fi
fi
IDX=$NEWIDX
done
The author of the script disclaims all warranty for this script, and releases it to the public domain (meaning you may use it and further distribute it under any terms you wish, including incorporating it into other software).
Fan enable/disable scripts
The following scripts were written before it was known how to control the fan speed, so they only toggle between fan disabled and default (noisy) fan behavior. In some models, they also do not monitor all available thermal sensors.
sh script example
#!/bin/sh
MAXTEMP=50
while [ 1 ];
do
fan=no
for temp in `sed s/temperatures:// < /proc/acpi/ibm/thermal`
do
test $temp -gt $MAXTEMP && fan=yes
done
command='disable'
test "$fan" = "yes" && command='enable'
echo $command > /proc/acpi/ibm/fan
sleep 20
done
sh script with more features
#!/bin/sh
# fan control-script
#
# based upon ibm-acpi 0.11 (experimental=1 !)
#
# eliminates anoying "fan always on" in battery mode
# works with hysteresis (DELTA) so that always-turn-on/turn-off is avoided
# fan acivates at MAXTEMP and cools down CPU, GPU etc. to MAXTEMP-DELTA than the fan is turned off
# furthermore detects if AC is on and gives back fan control to default behaviour than
#
# one can change MAXTEMP and DELTA to individual values
# but take care of your THINKPAD don`t melt it!
#
# have fun!
# mk 05.05.05
MAXTEMP=51
DELTA=4
SWITCHTEMP=$MAXTEMP
#make sure the script doesn't leave the fan off on error
trap "echo enable > /proc/acpi/ibm/fan" EXIT
while [ 1 ];
do
for ac in `sed s/state:// < /proc/acpi/ac_adapter/AC/state`
do
if [ "$ac" = "off-line" ]; then
fan=no
for temp in `sed s/temperatures:// < /proc/acpi/ibm/thermal`
do
test $temp -gt $SWITCHTEMP && fan=yes
done
if [ "$fan" = "yes" ]; then
command='enable'
SWITCHTEMP=`expr $MAXTEMP - $DELTA`
else
SWITCHTEMP=$MAXTEMP
command='disable'
fi
else # ac-adapter on -> set fan control to standard behaviour
command='enable'
fi
echo $command > /proc/acpi/ibm/fan
sleep 15
done
done
sh script with extra safety functionality
ibm_acpi usually works well. But to rely on it completely, this script provides some extra safety functionality:
- It catches various signals and turns the fan on before it quits.
- It turns off the fan under very strict conditions, leaving it on when unexpected errors occur.
#!/bin/sh
# july 2005 Erik Groeneveld, erik@cq2.nl
# It makes sure the fan is on in case of errors
# and only turns it off when all temps are ok.
IBM_ACPI=/proc/acpi/ibm
THERMOMETER=$IBM_ACPI/thermal
FAN=$IBM_ACPI/fan
MAXTRIPPOINT=65
MINTRIPPOINT=60
TRIPPOINT=$MINTRIPPOINT
echo fancontrol: Thermometer: $THERMOMETER, Fan: $FAN
echo fancontrol: Current `cat $THERMOMETER`
echo fancontrol: Controlling temperatures between $MINTRIPPOINT and $MAXTRIPPOINT degrees.
# Make sure the fan is turned on when the script crashes or is killed
trap "echo enable > $FAN; exit 0" HUP KILL INT ABRT STOP QUIT SEGV TERM
while [ 1 ];
do
command=enable
temperatures=`sed s/temperatures:// < $THERMOMETER`
result=
for temp in $temperatures
do
test $temp -le $TRIPPOINT && result=$result.Ok
done
if [ "$result" = ".Ok.Ok.Ok.Ok.Ok.Ok.Ok.Ok" ]; then
command=disable
TRIPPOINT=$MAXTRIPPOINT
else
command=enable
TRIPPOINT=$MINTRIPPOINT
fi
echo $command > $FAN
# Temperature ramps up quickly, so pick this not too large:
sleep 5
done
Init scripts
Init script example
#! /bin/sh
N=/etc/init.d/fan
set -e
case "$1" in
start)
# make sure privileges don't persist across reboots
if [ -d /var/run/fan ] && [ "x`ls /var/run/fan`" != x ]
then
touch -t 198501010000 /var/run/fan/*
fi
fan.sh & # Script from above
;;
stop|reload|restart|force-reload)
killall fan.sh
echo enable > /proc/acpi/ibm/fan
;;
*)
echo "Usage: $N {start|stop|restart|force-reload}" >&2
exit 1
;;
esac
exit 0
Init script example for gentoo
Assume one of the above control scripts is /usr/sbin/ibm-fancontrold, for gentoo use the following init script in /etc/init.d/ibm-fancontrol. Copy the script to /etc/init.d/ibm-fancontrol, then do
# rc-update add ibm-fancontrol default
This will add the init script to the default runlevel.
#!/sbin/runscript
# 2005 Gilbert Tiefengruber
# Distributed under the terms of the GNU General Public License v2
# IBM Fancontrol init script for IBM Thinkpad laptops (tested with R50)
# This init script was written for gentoo 2005.1, kernel 2.6.12
# You need the ibm_acpi kernel module version 0.11 or greater
# load the module with experimental=1 to enable the fan controls
depend() {
need localmount
}
checkconfig() {
if [ ! -e /proc/acpi/ibm/fan ]; then
eerror "The ibm_acpi module must be loaded with (experimental=1)"
return 1
fi
}
start() {
checkconfig || return 1
ebegin "Starting ibm-fancontrold"
start-stop-daemon --quiet -p /var/run/ibm-fancontrold.pid -m -b --start -a /usr/sbin/ibm-fancontrold
eend ${?}
}
stop() {
ebegin "Stopping ibm-fancontrold"
start-stop-daemon --stop --quiet -p /var/run/ibm-fancontrold.pid
eend ${?}
}
Other
fanctrld
fanctrld is a daemon (written in C) that controls the Thinkpad's fan. The basic approach is to monitor both temperature and fan speed. The fan is enabled when a certain temperature is exceeded, and disabled when the BIOS slows down the fan below a certain speed.
Ideas for improvement
- Use the HDAPS sensor to automatically lower the temperature thresholds when the laptop is moving. Prolonged movement usually happens when the laptop is on the user's lap (so better keep temperatures down), or when in a moving vehicle where fan noise is typically overshadowed by vehicle noise.
See also
- Shimodax's ThinkPad fan control tool for a Windows offers functionality similar to these scripts; see the forum discussion at thinkpads.com.
- Yury Polyanskiy has a kernel patch for automatic fan control in kernelspace (only enable/disable based on maximum temperature).
