Submitted by MagicFab on Sat, 01/12/2013 - 17:21
Optimizing battery time
This wiki page has tips on reducing your computer's electricity consumption. If you're using a laptop, it will help extend your battery life.
We tested these tips on a computer running Trisquel 6. Trisquel 6 is based on Ubuntu 12.04 LTS. The same information should be applicable to Debian, Trisquel 7, Ubuntu 14.04 LTS, and other Debian derivatives.
Tips & tricks
- Suspend the system when you're not using it.
- In the BIOS, disable every device that you don't plan to use. For example disabling all the following would save you around 2W:
- Ethernet (if you only/mostly use wireless)
- Wireless devices (your computer may have hardware switches for these):
- Bluetooth
- WiMAX
- Wireless WAN (3G)
- Wifi
- The touchpad (on a laptop)
- Sound card (estimated 2W savings):
- Right-click on the speaker in the task bar and choose "Sound preferences"
- In the "Hardware" tab, click on your sound card, then select the profile "Off".
- Disable wake-on-lan (how?) --which keeps the LAN port active (estimated 1W savings).
- Check your power usage statistics with the gnome-power-statistics command
- Set your system to reduce the screen brightness after a set amount of inactivity. This can be done in Trisquel Menu -> System Settings -> Brightness and Lock. Change the "Turn off screen when inactive for:" setting to the desired time.
- Use a solid state disk drive (SSD) - they use less electricity than regular hard disks.
Useful Packages
- GNU Linux-libre (homepage): Upgrade your kernel to its latest version following this guide: trisquel.info/wiki/update-linux-libre-kernel.
- laptop-mode-tools (homepage) : Tools for Power Savings based on battery/AC status
Laptop mode is automatically enabled after installing this package. Check the ArchLinux extensive documentation about this. - powertop (homepage) - tool to find out what is using power on a laptop
- rovclock - utility to control frequency rates of your Radeon card
Check the Thinkwiki rovclock documentation about this package - If you use a HDD, put your Abrowser profile on a ramdisk to avoid spinning the platter. Trisquel comes automatically with a ramdisk at /dev/shm. Note that the ramdisk is volatile, you might want to backup the profile before restarting/shutting down.
Remove excess VTs
Do you use virtual terminals 3-6? Get rid of them by removing /etc/init/tty3.conf ... /etc/init/tty6.conf, reboot.Runtime PM
When you run$ sudo powertop you may notice that many devices have runtime power management disabled. You can enable them all by echoing auto to their control files as super user, e.g. in a startup script. You can find a list of such files with $ ls /sys/bus/{pci,i2c}/devices/*/power/control
PCIe ASPM
Some newer hardware and BIOSes support PCIe active state power management. You can check$ sudo dmesg|grep -i aspm to see how your system is doing. You can try forcing it by adding to grub configuration, on the kernel line pcie_aspm=force and then running $ sudo update-grub and rebooting. Watch out for hangs.
