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.

PowerTOP is a Linux tool that finds the software component(s) that make your laptop use more power than necessary while it is idle. As of Linux kernel version 2.6.21, the kernel no longer has a fixed 1000Hz timer tick. This will (in theory) give a huge power savings because the CPU stays in low power mode for longer periods of time during system idle.