Ubuntu 7.10 "Gutsy Gibbon" is due out in just a few days and shipping with it is the Linux 2.6.22 kernel. One of the interesting additions to the Linux kernel since the 2.6.20-based Ubuntu 7.04 "Feisty Fawn" release has been the tickless kernel feature. If you hadn't read out tickless kernel article from earlier this year, the tickless kernel feature (CONFIG_NO_HZ) is designed to improve the power efficiency especially on servers and portable devices.
This CONFIG_NO_HZ feature works by enabling on-demand timer interrupts that allow a system to idle for a longer period of time and avoiding useless interrupts. This is not only designed to reduce power consumption but to allow for the system to run cooler and an extended battery-life for mobile devices.
For this article we've decided to not only deliver power benchmarks from Ubuntu 7.10 and Ubuntu 7.04 to compare the tickless kernel effect, but we have went back and retested all of the Ubuntu releases going back to Ubuntu 5.04, or also known as Hoary Hedgehog.