How to reduce power consumption

Reducing system power consumption will extend battery life, reduce system temperature and (on some models) reduce system fan noise. This page summarizes the known techniques for reducing power consumption on ThinkPad laptops under Linux. The power numbers given (in Watt) are very rough and model-specific.

System power states

• Power Management
• How to make use of Power Management features

CPU

• How to make use of Dynamic Frequency Scaling
• Pentium M undervolting and underclocking

Graphics

• How to make use of Graphics Chips Power Management features
• Problem with high power drain in ACPI sleep
• Rovclock
• Reduce LCD brightness (~1-4W difference)
• Disable CRT output (~0.5W difference)

Hard disk

Spinning down the disk saves about 1W.

• Laptop-mode
• How to make use of Harddisk Power Management features

Optical drive

The optical drive consumes about 1W even when not accessed.

• Eject the UltraBay optical drive, or just turn off its power supply (i.e., run the appropriate eject script but leave the drive inserted).
• Reduce the spinning speed of the optical drive.

System fan

Consumes about 0.5W when running.

• ACPI fan control script

Wireless network

Consumes up to ~4W.

• Activate power saving on the wireless network card
  • For Intel PRO/Wireless 2200BG Mini-PCI Adapter and Intel PRO/Wireless 2915ABG Mini-PCI Adapter, see instructions for the ipw2200 driver.

Related toptics

• How to measure power consumption
• Script_for_monitoring_power_consumption
• Battery maintenance

External resources

• Power Management Guide from the Gentoo Linux documentation
• When/where/what for low power consumption? (thread on Linux-Thinkpad)
• 8hours of battery life on your lap(top), a presentation by Pavel Machek