However... there are many things that can ruin the party, both inside the kernel and in userspace. PowerTOP combines various sources of information from the kernel into one convenient screen so that you can see how well your system is doing, and which components are the biggest problem.
For PowerTOP to work best, use a Linux kernel with the tickless idle (NO_HZ) feature enabled (version 2.6.21 or later). Currently, only 32-bit kernels have support for tickless idle; 64-bit kernels are expected to gain this feature in version 2.6.23.
This only applies to Feisty. Also note that you need kernel 2.6.21 or above.
Install the following prerequisites
sudo apt-get install build-essential libncurses5-dev libncursesw5-dev
Download the latest powertop source from here
Put the source in /usr/src and unpack using
sudo tar -xvf powertop-1.9.tar.gz
Compile using the following command
sudo make install
You can also use "checkinstall" instead of "make install" to create a simple .deb for easier removal.
If you are using Gutsy you can use the following command to install
sudo aptitude install powertop
Run powertop using the following command
Powertop Output shown as follows