Description
For consistent performance measurement, we want to run the CPU at a constant frequency. The frequency can be set by e.g.
sudo cpupower frequency-set -g userspace
sudo cpupower frequency-set -f 2.60GHz
The userspace
governor is not available if intel_pstate
driver is active. To disable it, add intel_pstate=disable
to the Linux kernel command line in /etc/default/grub
:
GRUB_CMDLINE_LINUX="intel_pstate=disable"
Then do sudo update-grub
and reboot the system, and use the cpupower
commands above to pin the CPU frequency.
This is what I also found using ChatGPT:
When you disable the
intel_pstate
driver, the system falls back to the olderacpi-cpufreq
driver. Even thoughacpi-cpufreq
doesn’t display the turbo frequency as a selectable max frequency, the CPU may still boost beyond 2.6 GHz under the right conditions. Turbo boost is often controlled by the CPU firmware and BIOS settings, independent of the frequency scaling driver.On many modern kernels, there’s a global switch to control CPU turbo/boost for acpi-cpufreq:
cat /sys/devices/system/cpu/cpufreq/boostA value of 1 typically indicates that boost/turbo is enabled.
A value of 0 indicates that it is disabled.
To disable boost/turbo:echo 0 | sudo tee /sys/devices/system/cpu/cpufreq/boostCheck again:
cat /sys/devices/system/cpu/cpufreq/boostYou should see 0, indicating that boost is now disabled.