Launchpad has imported 1 comments from the remote bug at https://bugs.freedesktop.org/show_bug.cgi?id=44627.
If you reply to an imported comment from within Launchpad, your comment will be sent to the remote bug automatically. Read more about Launchpad's inter-bugtracker facilities at https://help.launchpad.net/InterBugTracking. ------------------------------------------------------------------------ On 2012-01-10T11:42:20+00:00 Martin Pitt wrote: >From https://launchpad.net/bugs/900923: Colin King spent some days doing extensive and accurate power benchmarking [1], amongst others the effect of the pm-utils power.d scripts on various machines [2]. It turns out that the readahead and the journal-commit scripts do not actually save power these days (maybe they did at the time when they got introduced, but changes in the kernel nullified them?). No measurable difference on HDD, and on SSD power usage increases by 1.5%. This was confirmed on an idle system, on a system doing compiling/package build, and a workload with music playback and browsing, each 5 times over 60 minutes. Based on this it seems that these scripts should be disabled by default or removed. [1] http://zinc.canonical.com/~cking/power-benchmarking/ [2] http://zinc.canonical.com/~cking/power-benchmarking/pm-utils-results/ Reply at: https://bugs.launchpad.net/pm-utils/+bug/900923/comments/9 ** Changed in: pm-utils Status: Unknown => Confirmed ** Changed in: pm-utils Importance: Unknown => Medium -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/900923 Title: pm-utils: readahead and journal-commit waste power To manage notifications about this bug go to: https://bugs.launchpad.net/pm-utils/+bug/900923/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
