"Powertop is a command-line tool released by Intel that shows
you the power consumption of the applications running on your
system. It works best on notebooks with Intel mobile processors and
can help you find out the programs that put a strain on your
notebook battery. It requires kernel 2.6.21 or newer with tickless
idle enabled (CONFIG_NO_HZ) (which is currently available for
32-bit kernels only). Fedora 7 comes with a 2.6.21 kernel by
default, so we can use Powertop on it..."