power-profiles-daemon

Most distributions install power-profiles-daemon by default with their GNOME and KDE desktop environments. This article compares TLP and power-profiles-daemon and explains how to replace the latter with TLP.

Does power-profiles-daemon save power over TLP?

Simply put, power-profiles-daemon is a CPU throttle that is most effective when high or medium load applications are in use. Unlike TLP, it has no settings to reduce power consumption when the CPU is idle, such as when there is no user input.

power-profiles-daemon only covers a subset of TLP’s settings:

PLATFORM_PROFILE_ON_AC/BAT
CPU_ENERGY_PERF_POLICY_ON_AC/BAT
CPU_BOOST_ON_AC/BAT

The second item is only activated if the first item is not supported by the hardware. When the second item is active, turbo boost (third item) is also disabled at high CPU temperatures.

Which of these tools will save you more power depends on your workload:

If the laptop frequently runs under medium or high load, such as during video playback or compiling, using the power-saver profile with power-profiles-daemon can provide similar energy savings as TLP.
However, TLP offers advantages over power-profiles daemon when the laptop is idle, such as during periods of no user input or low load operations like text editing or browsing.

Note that TLP’s default settings do not enable PLATFORM_PROFILE_ON_AC/BAT and CPU_BOOST_ON_AC/BAT. To achieve truly comparable results, these settings must be explicitly configured in TLP. It is also important to note that some laptops, especially older ones, may not support PLATFORM_PROFILE_ON_AC/BAT.

Conclusion: To determine which tool provides superior results, conduct comparative measurements on your target hardware using your specific usage pattern.

Does power-profiles-daemon conflict with TLP?

Yes, it does. Using both tools at the same time can lead to unpredictable results as they partly change the same kernel tunables (see above) and overwrite each other’s tuning.

To prevent conflicts, many Linux distributions do not permit the installation of both TLP and power-profiles-daemon packages simultaneously. It is advisable to uninstall power-profiles-daemon in all other scenarios.

If your distribution allows for parallel installation, the behaviour depends on the version of TLP:

Version 1.6 and later will automatically not apply the settings listed above if a running power-profiles-daemon is detected. In addition the tlp start issues a warning about the conflict:

Warning: PLATFORM_PROFILE_ON_AC/BAT is not set because power-profiles-daemon is running.

Version 1.5 merely detects the situation and the commands tlp start and tlp-stat -s issue a message about the conflict:

Error: conflicting power-profiles-daemon.service is enabled, power saving will not apply on boot.
>>> Invoke 'systemctl mask power-profiles-daemon.service' to correct this!

If you do not want to use power-profiles-daemon in parallel, you can either uninstall the package (preferred) or, if that would uninstall essential packages, stop and disable the service with

sudo systemctl stop power-profiles-daemon.service
sudo systemctl mask power-profiles-daemon.service

How can I use TLP to achieve the same effect as power-profiles-daemon?

Firstly, it is important to understand the fundamental differences between the two tools:

TLP automatically selects the corresponding profile based on the power source: either AC or BAT.
power-profiles-daemon offers three profiles: power-saver, balanced and performance. These profiles must be manually selected through the panel applet, as there is no automatic switching between them. The default profile is balanced.
The settings for power-profiles-daemon’s profiles are hardcoded, while TLP’s profiles can be customized to meet specific needs.

It is evident from the above that TLP cannot fully replicate the behavior of power-profiles-daemon. However, two of power-profiles-daemon’s profiles can be mapped to TLP’s AC and BAT profiles, as demonstrated in the following examples:

Example 1: map balanced to AC and power-saver to BAT

PLATFORM_PROFILE_ON_AC=balanced
PLATFORM_PROFILE_ON_BAT=low-power

CPU_ENERGY_PERF_POLICY_ON_AC=balance_performance
CPU_ENERGY_PERF_POLICY_ON_BAT=power

CPU_BOOST_ON_AC=1
CPU_BOOST_ON_BAT=0

Example 2: map performance to AC and balanced to BAT

PLATFORM_PROFILE_ON_AC=performance
PLATFORM_PROFILE_ON_BAT=balanced

CPU_ENERGY_PERF_POLICY_ON_AC=performance
CPU_ENERGY_PERF_POLICY_ON_BAT=balance_performance

CPU_BOOST_ON_AC=1
CPU_BOOST_ON_BAT=0

Last but not least you may select TLP’s profile manually with a terminal command:

sudo tlp ac
sudo tlp bat