Power management

Resources

Wikipedia

Guide

This article describes methods to save energy for longer battery runtimes, a quieter computer, lower power bills, and an environmentally friendly impact.

Device-specific power management sub-articles can be found below in the Devices section.

Methods of power management

BIOS

Disable unused devices right in the BIOS or EFI firmware. Potential devices to disable include:

• Serial ports
• Parallel ports
• Ethernet network devices
• Wireless network devices
• Bluetooth controllers

Devices

Devices which can save energy during runtime:

• Processor
• Display
• HDD
• CDROM
• Graphics Adapters
• Ethernet
• Wifi
• Bluetooth
• Soundcard
• Bus

Multi-devices/subsystems power management:

• Hprofile

Low power modes

• Suspend and hibernate

Udev rules to automate power management

FILE /etc/udev/rules.d/10-local-powersave.rules

# PCI runtime power management
ACTION=="add", SUBSYSTEM=="pci", ATTR{power/control}="auto"

# USB autosuspend
ACTION=="add", SUBSYSTEM=="usb", ATTR{power/control}="auto"
ACTION=="add", SUBSYSTEM=="usb", TEST=="power/autosuspend" ATTR{power/autosuspend}="60"

# SATA active link power management
SUBSYSTEM=="scsi_host", KERNEL=="host*", ATTR{link_power_management_policy}="min_power"

# Wlan power save
ACTION=="add", SUBSYSTEM=="net", KERNEL=="wlan*" RUN+="/usr/sbin/iw dev %k set power_save on"

# Disable bluetooth
SUBSYSTEM=="rfkill", ATTR{type}=="bluetooth", ATTR{state}="0"

# Disable wake-on-LAN
ACTION=="add", SUBSYSTEM=="net", KERNEL=="eth*" RUN+="/usr/sbin/ethtool -s %k wol d"

See also

• Power management/Guide — covers the configuration of a Gentoo system to manage power-hungry resources in a flexible-yet-automated manner.

External resources

• https://www.linux.com/news/power-saving-linux - An article that provides generic explanations and advice for power saving on Linux.