PowerTOP is a command line tool that helps diagnose issues with power consumption and provides suggestions on how to improve power usage.
PowerTOP 2.1, released a few days ago, introduces support for Intel GPUs and for cores without P-states, a new manual page along with an option to specify workload to run during measurement and an option to suppress output to the terminal.
Install PowerTOP 2.1 in Ubuntu 12.04 via PPA
The latest PowerTOP 2.1 is available in the Ubuntu 12.10 official repositories, and for Ubuntu 12.04 in the main WebUpd8 PPA. Add the PPA and install PowerTOP 2.1 using the following commands:
sudo add-apt-repository ppa:nilarimogard/webupd8 sudo apt-get update sudo apt-get install powertop
The latest PowerTOP 2.1 source can be downloaded from HERE.
To use PowerTOP, you need to run it as root:
PowerTOP doesn't just diagnose power consumption issues, but it can also provide solutions. On the Tunables tab, you can see what you can do to save some power:
However, most of the settings are not saved and they are lost after a reboot. You, can, however, make them permanent, by using the commands provided in the PowerTOP html report. To generate an HTML report, run the following command:
sudo powertop --html=powertop.html
This will generate an HTML page which you can open in your web browser:
Here, you can see various information related to power usage as well as a "Tuning" tab where the settings that need tuning are displayed, along with the commands required to apply them. Add these commands to the /etc/rc.local file to make them permanent.