subject: Using Powertop to Lower System Power Usage [print this page] Using Powertop to Lower System Power Usage
Ever wonder what's sucking the life out of your Linux laptop's battery or contributing to higher electric bills in the server room? Check out Powertop, a tool for profiling a system to see what is using the most power.
Powertop was developed a few years ago to help profile systems and primarily see what could be done to make Linux better at power savings. It was aimed primarily at laptops, as many folks would install Linux on a laptop and then find out that battery performance was far worse under Linux than Windows.
You don't even need to run Powertop to benefit from it. Some of the most common power-gulping culprits are listed on the LessWatts.org website. Many of these have been fixed in the upstream projects that caused unnecessary wakeups (like ntp waking up every second, or Pidgin checking every 5 seconds to check on idle time). Something as unnecessary wakeups simple as a blinking cursor can cause a wake up every few seconds, and additional power consumption.
Some of the problems uncovered by Powertop are going to be beyond your control. While Powertop gives several tips that you can follow, like tuning the kernel to reduce wakeups, sometimes it just reports that an application is doing something silly. However, unless you are going to re-write the application yourself, not much can be done about it. You can file a bug though, assuming it's egregious yet sane enough to fix.
But Powertop will also provide suggestions on how to tune the kernel or make other changes that will provide better power performance. For example, Powertop suggests increasing the timer for writing to disk to decrease the number of wakeups.
Spend a few hours with Powertop and you'll learn much more about what goes on behind the scenes. You might even be able to boost your battery life and be a little greener to boot!
