LessWatts is a public repository of Intel-led projects, including downloadable power diagnostic tools, white papers, frequently asked questions, and user-contributed tips and ideas. Depending on the nature of the project, the results of these initiatives are available for free download on the site and some have been incorporated as improvements to the Linux kernel. "We thought, 'Let's make it one-stop shopping,' " said Arjan van de Ven, the lead developer and kernel engineer, who boasts an extra hour and a half of laptop battery life, thanks to LessWatts.
With all the information on the site, it's easy to become overwhelmed. If you're motivated but aren't sure where to start, van de Ven recommends PowerTop. The diagnostic tool locates applications that consume power needlessly while a machine is in idle mode. By displaying key data from multiple points inside the kernel on a single screen, PowerTop enables users to pinpoint which components waste energy and, conversely, how well energy-saving devices work.
With PowerTop, researchers discovered that a prime energy waster was what LessWatts calls "the Tickless Idle," which wakes up a CPU periodically for routine operations, such as process accounting or scheduler load balancing, regardless of whether a computer is idle. As a result of this project, versions 2.6.21 and following of the Linux kernel were modified to eliminate this feature so routine procedures occur only while a computer is active.
Michael Larabel, the founder of Phoronix, a Web site that reports on the testing of Linux hardware, said the most helpful tool on LessWatts is PowerTop. "PowerTop is easy to use and can noticeably extend your notebook's battery life," said Larabel, a Linux software developer. "It does a good job [of] eliminating the processes most users can do without." Its only shortcoming is that it doesn't explain the commands or their impact, he said. Nevertheless, PowerTop is a must-have for any mobile Linux user, he added.
Some of LessWatts' other projects include the following:
- Power Policy Manager. A power framework that gives administrators more options for power control.
- Applications Power Management. A tool to determine actual power consumption by applications.
- Processor Power Management. An informational site about Intel power management features, including those that have been incorporated into the Lnux kernel.
- BLTK.The Linux Battery Life Toolkit is a test with six examples to measure power consumption during different operations.
- Device and Bus Power Management. A power measurement tool for hardware devices and buses.
So too, optimizing hardware efficiency isn't enough. As evidenced by LessWatts' projects, the power culprit may be software, van de Ven said. By running needlessly in the background or operating an unnecessary timer, software can work counter to hardware efficiency, he said.A hands-on resource
With the increasing focus on curbing data center energy consumption, LessWatts is poised to become a significant resource for data center managers in search of hands-on advice.
"I do a fair amount of energy consulting, and I think it's a great advisory site for companies trying to get a handle on energy consumption and figure out what to do about it," said Joe Clabby, the principal of Yarmouth, Maine-based Clabby Analytics. Clabby was impressed by the site given its wealth of information, depth of research and level of community involvement.
The documentation section offers myriad resources, including Energy Star recommendations for laptops, Clabby noted.
SearchLinuxEnterprise.com expert Sander van Vugt, also gave a thumbs-up to LessWatts' tips section, although he noted that these how-tos target end users. He welcomed the suggestion on disabling Bluetooth, however, and said the wireless and disk tips would be first on his to-do list. ""These are pretty good tips that really help in reducing power without causing too much inconvenience for the user," van Vugt said.
As for the site itself, projects will be added and deleted as new issues arise; user contributions are always welcome, van de Ven said. As for visitor traffic, the volume seems to ebb and flow along with the level of concern about power consumption.
Asked whether Linux or Windows is more efficient, van de Ven took the Fifth. "Intel is neutral," he said. "The company doesn't like external comparisons. I'd like to know which is the best operating system and the size of the gap. But individual laptops and device drivers can make a lot of difference [in test results]."
With data center managers increasing power efficiency, will all the savings afforded by LessWatts get gobbled up by larger workloads and, in turn, more power consumption?
"Data center people have an infinite demand for power," he admitted. "I don't know what they will do."
Let us know what you think about the story; email Pam Derringer, News Writer