Wiki » Power saving

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General behaviour

The systemd daemon manages power if no other programs are watching ACPI events. It manages :

- the power and suspend buttons, - power plug events

When a desktop like Plasma is running, it takes over control of the power and button events, and you can configure what to do.

More powersave

• For dual GPU, check out Mageia prime for Optimus - Or if you only want to use the power efficient one, configure only that one if possible.

• The package cpupower comes with a startup service which configures the CPU scheduler to performance. While this is a good setting for recent CPUs, with older ones the 'ondemand' governor enables frequency scaling. With an idle AMD 5400B, a powermeter shows going from 52 Wh to 40Wh. This setting can be changed in the file /etc/sysconfig/cpupower .

• PowerTOP, diagnostic tool, package powertop comes with a startup service which configures further all powersave for USB, PCIe and SATA ports. It can give more 20% powersave on some hardware. Also see Archwiki article

• TLP, package tlp, plus for wireless: tlp-rdw

Cleaning

A dense layer of dust between your fan and your CPU heat sink can make your CPU very hot, and, by reaction, very slow (up to 5 times slower in my case) and your fan very noisy. Eventually, our computer will begin to stop suddenly when it gets too hot. To increase air flow across the more important parts of your computer, you should close those gaping expansion slot openings at the back of your computer that you don't use any more (with sellotape if there is nothing else), and clean your computer inside twice a year. Depending on your contract, it's possible your guarantee get void if you open the box. In such a case, consider having your computer cleaned by your reseller.

Before cleaning your computer, unplug it from the mains. Synthetic clothes may carry static electricity, dangerous for your computer.

When cleaning your computer, stop the fans from moving BEFORE blowing or sucking the dust off them. Spinning the fans with a vacuum cleaner can damage the fan controllers and/or motors.

Keeping the room cool

The hotter is the room your computer is in, the more difficult it is to evacuate the heat, and the more energy will be used for that. Keep your computer room cool and well ventilated.

Suspend

Userland support

systemctl interface

systemctl is the official suspend interface. It takes care of shutting down services and removing modules before going to suspend and restart those things after coming back.

Usage: systemctl suspend or : systemctl suspend-hybrid or : systemctl hibernate

Frontends

These applications call systemd to trigger to suspend:

• plasma
• gnome-power-manager