"Intel's Open Source Technology Center is pleased to announce the LessWatts.org project, an open source project for saving power on Linux," began an email posted to the lkml by Arjan van de Ven. The announcement continued:
"LessWatts.org is a place to bring users, developers and distribution makers together around power reduction for linux machines, from mobile to desktop to server to datacenter. LessWatts.org is about a system-level approach to power savings, from the lowest level device drivers in the kernel to the most advanced desktop applications. LessWatts.org is about things you can do to reduce power usage. LessWatts.org is about longer battery life, a lower airconditioning bill, about reducing the impact of computers on the environment."
The announcement went on to note, "at this time of launching the LessWatts.org project, the technology development projects are those that Intel has started, is involved in or has just started working on, such as PowerTOP, Tickless Idle, Graphics and various link power management techniques. We'd like to invite all developers and projects that focus on power saving to join the LessWatts.org effort and community."
"With all the tickless [story] and other goodies going into the kernel in the last few months, there is a lot of hope that this helps Linux reduce power consumption," Arjan van de Ven began on the lkml, "and the good news is that it does... once you fix some bugs and fix a bunch of userspace applications." He referred to a promising graph generated utilizing the recently introduced PowerTOP utility [story], measuring power consumption before and after applying a series of related bug fixes.
The tests began with a Lenovo T61 laptop running the stock 32-bit Fedora 7 kernel which includes the tickless kernel. This was compared against the stock 2.6.22-rc4 kernel with a series of improvements including a fix for the Ondemand CPUFREQ governor, the new CPUIDLE infrastructure, the Active Link Power Management patch, disabling the laptop's TV-out capability, and using a cli utility to properly reduce the laptop's backlight. Arjan summarizes, "with kernel fixes and features, the power consumption of this laptop went from 21.06 Watts to 18.25 Watts; with 2 additional userspace fixes the power consumption ended up at 15.5 Watts."