Power Management Power Management for laptops refers to optimizing the system to last as long as possible on a single battery charge. This can be accomplished by a variety of tweaks.
#Suspend and Hibernate : the operating system can be manually suspended either to memory or to disk, allowing for an (almost) complete shutdown of other hardware.
Hard drive spin down : the system can be configured to automatically turn off the hard disk after a specified interval of inactivity.
Screen shut off : the laptop screen can be configured to automatically turn off after a specified interval of inactivity (not just blanked with a screensaver but completely shut off).
CPU frequency scaling : the processor(s) can be configured to automatically step down to a lower frequency at lower loads.
#Screen brightness. How do I manage screen brightness?Network and wireless setup is described in Wireless Setup.
Media buttons can be configured as described in Extra Keyboard Keys.
#Touchpad sensitivity, acceleration, button function and scroll borders can be configured for some (Synaptics or Alps) touchpads.
Hard disk shock protection
All of these points are important to take into consideration when getting a laptop set up the way you like. Fortunately, Arch Linux provides all the tools and programs necessary to take complete control of your laptop. These programs and utilities are highlighted below, with appropriate tips tutorials.
Power Management
Power management is very important for anyone who wishes to make good use of their battery capacity. The following tools and programs help to increase battery life and keep your laptop cool and quiet.
Battery State Monitoring Utilities
Battery state can be read using ACPI utilities from the terminal. The command line utilities that ACPI functionality is provided via the acpi package.
Manually suspending the operating system, either to memory (standby) or to disk (hibernate) sometimes provides the most efficient way to optimize battery life, depending on the usage pattern of the laptop. While there is relatively straightforward support in the linux kernel to support these operations, typically some adjustments have to made before initiating these operations (typically due to problematic drivers, modules or hardware). The following tools provide wrappers around the kernel interfaces to suspend/resume :
Automatic tweaks for battery life
As opposed to manually initiated actions like suspend/hibernate, a number of tweaks can be made to prolong the battery life of the laptop under low/idle usage.
Cpu frequtils provides CPU frequency scaling, a technology used primarily by notebooks which enables the OS to scale the CPU frequency up or down, depending on the current system load and/or power scheme.
Laptop Mode Tools provides a comprehensive suite of tools to tweak a large number of power saving settings through well documented config files.
PowerTOP is a handy utility from Intel that displays which hardware/processes are using the most power on your system, and provides instructions on how to stop or remove power-wasting services. Works great for mobile Intel CPUs; provides the current CPU state and suggestions for power saving. Also works on AMD systems, but does not provide as much information about the CPU state.
Powernowd is a program for powering down CPUs dynamically, which can be run either on an AMD-based system or an Intel-based system. However, cpufrequtils detailed above provides a more modern alternative, as seen by the fact that powernowd was created before the ondemand governor existed.
Some of these tweaks are specific to certain makes.
Lapsus is a set of programs providing easy access to many features of various laptops. It currently supports most features provided by asus-laptop kernel module from ACPI4Asus project, such as additional LEDs, hotkeys, backlight control etc. It also has support for some IBM laptops features provided by IBM ThinkPad ACPI Extras Driver and NVRAM device.
TLP for Thinkpads is a set of scripts, which set many powersaving options according to the current Powersource. TLP is intended to be used on Thinkpads, but most settings should work on other laptops too.
