How hot does it get?

Warmluft is a program to help testing a computer's cooling system. The program logs the CPU temperature while generating CPU load.

The resulting log files can be visualized by tools like gnuplot:

This picture shows the effect that a little bit of compressed air can have on a laptop's cooling system.

Download and installation

Download the latest release

warmluft 0.2.1

You may want to verify the signature or have a look at the release notes. If you are interested in versions other than the current release, you can check the list of all releases.


Warmluft uses the meson build system. To compile it, run:

meson builddir/
cd builddir/


Warmluft will try to find a suitable temperature sensor. If you are unhappy with its choice, use the -d parameter to specify a different sensor:

./warmluft -d /sys/class/hwmon/hwmon0/temp2_input

Usually these sensors define a maximum temperature, warmluft will terminate once that temperature is reached. If the sensor fails to provide this information, you will need to do so yourself:

./warmluft -m 58

This command will terminate once the sensor reports 58°C. You may also want to test the temperature on a system that never reaches the maximum:

./warmluft -t 20

With this option, the application will terminate after 20 minutes.

When messing with your system's cooling, it's good to know whether you are making any progress. That's why warmluft can log the current temperature value to a file at regular (1 minute) intervals:

./warmluft -f /path/to/log/file

By default, warmluft will start one child process per CPU core in your system. These child processes are the ones that generate the system load. If you want a different number of processes, you can have just that:

./warmluft -n 8

This command will start 8 child processes.