Reducing power consumption for background tabs
By Alexander Timin, Google Software
Engineer and Power Saver
March 16, 2017
power usage is an important aspect of speed, one of
Chromeís key pillars. To prolong
battery life, Chrome should minimize power impact from things users
canít see. This includes background tabs, which consume a third of
Chrome's power usage on desktop. Starting in version 57, Chrome will
throttle individual background tabs by limiting the timer fire rate for
background tabs using excessive power.
Chrome has focused on improving the user experience by throttling tab
performance for many years. Like many browsers, Chrome has limited
timers in the background to only run once per second. Via the new
throttling policy, Chrome 57 will delay
timers to limit average CPU load to 1% of a core if an application uses
too much CPU in background. Tabs playing audio or maintaining real-time
connections like WebSockets or WebRTC wonít be affected.
found that this throttling mechanism leads to 25% fewer busy background
In the long-term, the ideal is for
background tabs to be fully suspended and instead rely on new APIs for
service workers to do work in the background. Chrome will continue to
take steps in this direction to prolong users' battery life, while still
enabling all the same experiences developers can build today.