Manage Intel Turbo Boost with systemd

source: https://blog.christophersmart.com/2017/02/08/manage-intel-turbo-boost-with-systemd/

If you have a little laptop with an Intel CPU that supports turbo boost, you might find that it’s getting a little hot when you’re using it on your lap.

For example, taking a look at my CPU:

lscpu |egrep "Model name|MHz"

We can see that it’s a 2.7GHz CPU with turbo boost taking it up to 3.5GHz.

Model name: Intel(R) Core(TM) i7-7500U CPU @ 2.70GHz
CPU MHz: 524.633
CPU max MHz: 3500.0000
CPU min MHz: 400.0000

Here’s a way that you can enable and disable turbo boost with a systemd service, which lets you hook it into other services or disable it on boot.

By default, turbo boost is on, so starting our service will disable it.

Create the service.

cat << EOF | sudo tee \
/etc/systemd/system/disable-turbo-boost.service
[Unit]
Description=Disable Turbo Boost on Intel CPU

[Service]
ExecStart=/bin/sh -c "/usr/bin/echo 1 > \
/sys/devices/system/cpu/intel_pstate/no_turbo"
ExecStop=/bin/sh -c "/usr/bin/echo 0 > \
/sys/devices/system/cpu/intel_pstate/no_turbo"
RemainAfterExit=yes

[Install]
WantedBy=sysinit.target
EOF

Reload systemd manager configuration.

sudo systemctl daemon-reload

Test it by running something CPU intensive and watching the current running MHz.

cat /dev/urandom > /dev/null & echo 'This process run forever! Remember to kill it!'
lscpu |grep "CPU MHz"

CPU MHz: 3499.859

Now disable turbo boost and check the CPU speed again.

sudo systemctl start disable-turbo-boost
lscpu |grep "CPU MHz"

CPU MHz: 2699.987

Don’t forget to kill the CPU intensive process 🙂

kill %1

If you want to disable turbo boost on boot by default, just enable the service.

sudo systemctl enable disable-turbo-boost

As turbo boost is enabled on a Linux system by default, to turn it back on you just need to turn off the script which disables it.

sudo systemctl disable disable-turbo-boost