Hi John, Power consumption is definitely an area that Fedora can improve, and an area where we've begun to do some investigation.
Measuring battery life is hard, because when power saving is working, battery life depends so much on what the user is doing. Many manufacturers don't even provide battery life in their specifications or at most, provide a rough figure like "battery lasts up to 10 hours". Doing what? I've begun writing a test suite that will simulate events of "typical user activity" (web browsing, word processing), so that we can at least know machine-to-machine or Fedora-version to Fedora-version how well we are doing with battery life. Comparing with a different operating system is hard, since we typically have no idea how claimed numbers are measured. The second part of trying to improve power management is getting an understanding of what actually uses power. powertop is impressive, but can't always be taken at face value. I have some idea that we could build up a database (or at least a wiki page or two) with detailed information on power usage for a few representative models so that we can get an idea about how we need to modify the system software. On my laptop (ASUS ux301la), various things surprised me: * The backlight eats a ton of battery - 4W for the display backlight and 1W for the keyboard backlight. If you are getting poor battery life, turn off the keyboard backlight and turn the screen down. But how do we fix this for all users? We used to be much more aggressive about screen dimming in GNOME, and it was really annoying. Can we find some happy medium? * Although most of the "tunables" in powertop did little that could be measured, the "Enable SATA link power management" tunable saves 2W(!) We need to consider whether this should be enabled by default, at least on battery. * The next big offender on my system was inactive tabs with Flash ads in them. If I have nytimes.com open on my system, that's another 2W. How do we fix this for all users? Can we suspend plugins if there's no audio playing? This topline stuff is huge for battery life - on my laptop it makes a difference between around 3 hours and around 7 hours. The rest is hard - many small things that individually contribute just a little bit. Plus a baseline of things like DRAM refresh that are fixed. Having detailed data for multiple laptops (and definitely Macbooks are a interesting target) would help us make sure that Fedora does a good job out of the box. I don't think literally just including a set of scripts that tweak a bunch of things is something we'd want to do, but understanding what they are tweaking and how that affects power usage would be incredibly useful. - Owen -- devel mailing list devel@lists.fedoraproject.org https://admin.fedoraproject.org/mailman/listinfo/devel Fedora Code of Conduct: http://fedoraproject.org/code-of-conduct
