[ Thanks to panayara
for this link. ]
“Since version 2.6.21, the Linux kernel has introduced
a feature called tickless. the kernel no longer has a fixed 1000Hz
timer tick. This will give a dramatic power savings because the CPU
stays in low power mode for longer periods of time during system
idle.“A Nice handy tool, PowerTop has been created for reducing the
Power Usage of Linux. This application will help to find the
software components that are preventing optimal usage of your
hardware and give proper suggestions for both hardware and software
configurations to reduce power consumption of your system”