I run distributed computing projects, which typically want to use 100% of the CPU. How do I limit the CPU usage in terms of temperature instead of percent usage? Also, what is the maximum safe temperature to keep an Intel i5 running 24/7? (With no CPU limit FahCore_a4 causes this machine to run at 82 degrees Celsius.)
6 Answers
On this webpage there is a bash script that will attempt to keep your CPU below a specified temperature. http://seperohacker.blogspot.com/2012/10/linux-keep-your-cpu-cool-with-frequency.html
You just need to provide it with your desired maximum temperature, and it will throttle your CPU(s) in an effort to stay below that temperature.
Shameless plug- I wrote and maintain the above script.
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2Whilst this may theoretically answer the question, it would be preferable to include the essential parts of the answer here, and provide the link for reference.– fossfreedom ♦Commented Nov 19, 2012 at 16:47
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1here are essential parts: github.com/Sepero/temp-throttle Commented Jul 17, 2014 at 20:14
Here is how I solved it using bash. If anyone comes up with a better daemon (better at staying near the target temperature) please post it.
#!/usr/bin/env bash
while true; do
val=$(sensors | awk '/Core 0/ {print $3}')
max="+60.0"
if [[ "$val" < "$max" ]]
then
killall cpulimit
sleep .1
else
cpulimit -e FahCore_a4 -l 99 &
sleep 1
fi
clear
sensors
done
The CPU itsself has a mechanism where it powers itsself down if it gets too hot. (maybe not if you disable SMI interrupts, I'm not sure about that.)
The main user-space application is the lm-sensors
package. After installing it run sensors-detect
to set it up, if your machines are the same you can run this once, and use the resulting findings everywhere.
CPU frequency is easily controled via the cpufreq driver subsystem. see https://wiki.archlinux.org/index.php/CPU_Frequency_Scaling
You could write a daemon that uses lm-sensors to poll the temp and if its too hot turn down the cpu frequency.
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what language would writing such a daemon be easiest in? bash, python, awk?– nahanoCommented Aug 3, 2012 at 7:43
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This is how I solved my overheating problems, which were not caused by a specific process, but by failure of my laptop to dissipate the heat caused by running on a high CPU load for longer periods of time. The main difference to the solution offered by jeffythedragonslayer's answer is that I use CPU frequency scaling, instead of using cpulimit
on a specific process. Since I have Psensor installed and running anyway, I piggyback on Psensor. A daemon like the other answer suggested should also work, however two thresholds (min and max) are required. In Psensor (Sensor Preferences->Alarm) I set an alarm for the relevant sensor if it becomes higher than the high threshold (I use 85) or lower than the low threshold (I use 80). In Preferences->Sensors->Script executed when an alarm is raised, I call my script heatcontrol.sh like this:
heatcontrol.sh powersave ondemand 82
The first parameter is a valid scaling_governor which reduces CPU frequency, e.g. powersave. The second parameter is the default scaling_governor - ondemand for most systems. The third parameter is a temperature between low and high threshold (the exact value is not important). Psensor adds two more parameters: a sensor ID and the temperature reported.
And this is my heatcontrol.sh
script:
#!/usr/bin/env bash
# TempNZ is temperature reported by Psensor; strip of trailing °C
TempNZ=$5
bnum=$(expr index "$TempNZ" "°")
if (( bnum < 2 )); then
echo "ERROR"
fi
TempNZ=${TempNZ:0:$(($bnum-1))}
STR=$1
# Is this a low threshold alarm?
if [ "$TempNZ" -le "$3" ]; then
STR=$2
fi
sudo sh -c "echo '$STR' > /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor"
# echo new scaling_governor
sudo cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor
# play sound - audio feedback - optional
paplay /usr/share/sounds/ubuntu/stereo/message-new-instant.ogg
Works fine for me (UBUNTU 14.04 LTS).
Being a novice to Linux and bash, I used a number of resources, including:
"Safe" temperature
The maximum safe temperature for a CPU is usually specified on its technical specs from the manufacturer. A maximum of 100°C is pretty common. You may want to stay several °C below this value to have some margin (safety and maybe longevity of component).
Also, the CPU heating will tranfert some of its heat to the other, physically close, components of your computer. You may want to make some tests and monitor the temperature of these while your CPU is running at 100%, to check if you don't get too close to their limits in the long run. Better to test this during a hot day. :)
Temperature regulation
Then you can install
thermald
which is a program designed to monitor and limit CPU temperature using various techniques.Finally, Intel Core CPUs for example have an internal temperature limiting mechanism that you can configure below the 100°C mentioned above, by choosing a margin in °C.
See this answer for more details.
Ubuntu 22.04
need find device /sys/devices/virtual/thermal/cooling_device*/type
with "type" "TCC Offset"
cat /sys/devices/virtual/thermal/cooling_device6/type
TCC Offset
to set max 80C temperature ( 100 - 20 = 80 )
echo 20 > /sys/devices/virtual/thermal/cooling_device6/cur_state