OS X Mavericks' new App Nap, Timer Coalescing features target battery efficiency

Posted:
in macOS edited January 2014
Apple plans to advance its leadership in notebook battery efficiency with a series of new features in OS X Mavericks designed to achieve substantial power savings while maintaining or even improving upon the "snappy" responsiveness of the system.

MacBook Pro internals


In addition to the previously considered Compressed Memory feature of the upcoming OS X Mavericks, which aims primarily to make the most efficient use of available memory while enhancing battery life on the side, Apple has profiled two other advanced features of the new release that are aimed directly at extending battery life and two enhancements targeting web browsing and video playback.

App Nap

The first is App Nap, a new OS architecture feature that monitors each running application to determine what priority it should get in terms of processor, network and disk resources.

For example, if an app is running invisibly the background, OS X Mavericks can transfer disk and processor priority to the foreground app, improving the apparent responsiveness of the system.

The system analyses several factors to determine which apps should get full access to the CPU, storage and network resources and which should be throttled back.

Among the heuristics Apple applies to calculate and assign priority are whether a background app's windows are even visible or whether it playing audio the user wants to hear. Developers can also opt out of App Nap while performing an important task.

But Apple's overall design philosophy for App Nap keeps the feature active by default for apps in the new release, requiring fewer necessary changes for existing apps in order to benefit, while delivering the greatest energy savings possible. Developers can also make minor changes to take even fuller advantage of the new feature.

App Nap gets particularly aggressive in throttling back less important tasks when the user is running on battery power. A series of actions seek to keep CPU cores, disks and network devices idle and in low power modes as much as possible.

Timer Coalescing

Integrated with App Nap is a parallel feature named Timer Coalescing that aims to coordinate the resource demands from different apps and background task so that once system resources are awakened to do necessary work, a variety of other pending tasks can be performed at the same time.

This delivers real results in efficiency because without such coordination, the system's components must be constantly woken from idle to handle a flurry of randomly occurring tasks, preventing the system from ever getting enough sleep to take advantage of idle mode power savings.

Timer Coalescing
Source: Apple


With Timer Coalescing, the system's various tasks are either deferred or shifted so that they can be executed at the same intervals, enabling processor cores to go fully idle for longer periods of time in between.

Timer Coalescing
Source: Apple


"Grouping operations allows your CPU to spend more time in a low-power idle state, using energy more efficiently with no compromise in performance," Apple notes in its OS X advanced technologies preview of OS X Mavericks.

Timer Coalescing's coordination of tasks is illustrated in before and after images portraying a 2 second snapshot of activity (below).

Timer CoalescingTimer Coalescing
Source: Apple


"This can dramatically increase the amount of time that the processor spends idling," the company adds in its core technology overview. Apple notes that OS X Mavericks new efficiency features can reduce battery consumption by up to 23 percent, with little or no impact apparent to the user.

Safari Power Saver

Noted in our previous report on enhancements to Safari 7.0, Apple is now suspending web plugins until the user decides to view them.

"Many websites display animations using power-hungry plug-ins that can drain precious battery life," Apple notes in a feature aimed directly at Adobe Flash animations and ads.

"The new Safari Power Saver feature recognizes the difference between what you came to see and the stuff you probably didn?t. If the content is front and center it plays as usual. But if it?s off in the margins, Safari Power Saver pauses it. You?ll see a static preview, and it won?t run until you click to play it."

Timer Coalescing
Source: Apple


This feature works similar to the existing "Click to Flash" plugin, displaying a placeholder users can click to load as they choose (above). Apple says that with the new feature, "browsing websites with plug-in content will use up to 35 percent less CPU power."

Combined with other advances in Safari 7, Apple claims a performance advantage over both Mozilla Firefox and Google Chrome, while using significantly less power than either alternative (below).


Safari 7

Enhanced hardware acceleration for H.264 media playback

Also new on the battery efficiency front in OS X Mavericks is enhanced support for offloading media playback to the GPU to take full advantage of hardware acceleration.

In the new release, OS X's "video playback engine takes greater advantage of the efficient graphics hardware in your Mac and reduces the frequency of disk access," Apple states.

The improvements apply to both audio and video playback. Apple says users can "go ahead and watch iTunes HD TV shows and movies full screen even when you?re unplugged" and states "your CPU will use up to 35 percent less energy while you?re watching video."

Apple's focus on MPEG H.264 standards-based media playback and its optimizations for hardware acceleration on both OS X and iOS stand in stark contrast to efforts by Google and Mozilla to push ideological objectives that relied upon less sophisticated and efficient software codecs.

Google's efforts to subvert H.264 playback on the web with its own WebM have not only failed to gain traction, but have done so at the expense of optimizing Android or ChromeOS to play real world media, leaving its users with devices that run hotter and deliver either inferior playback performance or require massive batteries.
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Comments

  • Reply 1 of 32
    chandra69chandra69 Posts: 638member


    Why to post all these obvious things?  That too 1 week old things?

  • Reply 2 of 32
    gtrgtr Posts: 3,231member
    I'm looking forward to seeing what these features are going to be like on the new 'all day' MacBook Airs...
  • Reply 3 of 32
    isteelersisteelers Posts: 738member
    gtr wrote: »
    I'm looking forward to seeing what these features are going to be like on the new 'all day' MacBook Airs...

    I'm curious as well. It would also be interesting to see how much battery life it can eek out of older hardware.
  • Reply 4 of 32
    quadra 610quadra 610 Posts: 6,743member
    Running the preview now on an early 2008 MBP, 15-inch, 6GB RAM.

    It's a thing of beauty. Some minor bugs (it's still early, obviously), but it seems to perform better than ML (and ML did beautifully on my hardware.)
  • Reply 5 of 32
    macfandavemacfandave Posts: 603member


    This is really clever stuff and should rightfully be generating more excitement in the tech press.


     


    Apple should simply have claimed to have invented a better battery.  This would be easier for the morons that call themselves tech journalists and financial analysts to comprehend.  Giving the details how Apple achieves superior battery life appeals to us geeks, but it confuses the idiots whose pea brains shut down before they get to the result of longer battery life.


     


    Just tell them you've invented a lithium-titanium battery with 50% longer life and they'll go ape-s***!

  • Reply 6 of 32


    Intel just announced that they are delaying their 14 nm Tic or process upgrade by one year.  We are watching Moore's Law die a slow and steady death and Apple seems to be the only company who has all the pieces in place to take advantage.  They have their own low power processor, an advanced OS that they are making more and more energy efficient, and if the current trend continues not having a FAB could be a huge advantage. Intel is waiting for some new technology that opens the door to more improvements that may have different manufacturing requirements.  If there is a process wall at 14 or 10 nm it will make things really difficult for Samsung's foundry as well. Samsung's diversification will certainly help them weather this.  

  • Reply 7 of 32
    zozmanzozman Posts: 391member

    Quote:

    Originally Posted by GTR View Post



    I'm looking forward to seeing what these features are going to be like on the new 'all day' MacBook Airs...


    100%, makes me seriously consider upgrading my 11" 2010 air, i have the rMBP 15, but with Mavericks & more haswell updates coming, i'm wondering what the batt life will be like on the rMBP 13......


    Damn you apple for making me want to buy all your stuff...

  • Reply 8 of 32


    There's no question Mavericks is making OSX the most advanced operating system in the world even better. Quite the contrast as Windows 8 goes into the tank while OSX Mavericks is being praised.

  • Reply 9 of 32
    elrothelroth Posts: 1,201member


    As a Snow Leopard lover and Lion/Mountain Lion avoider, it's going to be really hard to resist Mavericks.

  • Reply 10 of 32

    Quote:

    Originally Posted by macFanDave View Post


    This is really clever stuff and should rightfully be generating more excitement in the tech press.


     


    Apple should simply have claimed to have invented a better battery.  This would be easier for the morons that call themselves tech journalists and financial analysts to comprehend.  Giving the details how Apple achieves superior battery life appeals to us geeks, but it confuses the idiots whose pea brains shut down before they get to the result of longer battery life.


     


    Just tell them you've invented a lithium-titanium battery with 50% longer life and they'll go ape-s***!



    Good point(s)! :) It was impressive in the Keynote where Apple demoed a "resource intensive" website window and when another window covered it, the CPU requirements went way down. Very, very cool! :)

  • Reply 11 of 32
    auxioauxio Posts: 1,980member

    Quote:

    Originally Posted by macFanDave View Post


    This is really clever stuff and should rightfully be generating more excitement in the tech press.



     


    Indeed.  Bud Tribble's presentation on the new power management technology in Mavericks was one of the most interesting sessions at WWDC this year.  It's inspiring to see how deeply they thought about this (from hardware to software).

  • Reply 12 of 32
    slurpyslurpy Posts: 5,118member


    My friend installed mavericks on his new Air, and it was giving him battery life estimates of 15 hrs. Utterly insane. The people that bitch about Apple's lack of innovation miss the innovations in front of their eyes, hundreds of which are required to make such a thin laptop with by far the best battery life in the industry. That's innovation with direct benefit to every single user. 

  • Reply 13 of 32
    sockrolidsockrolid Posts: 2,788member


    Originally Posted by macFanDave View Post


    This is really clever stuff and should rightfully be generating more excitement in the tech press.



     


    I see your point.  But maybe slow and steady low-profile improvements work to Apple's advantage.


    Constant improvements all add up, as we've seen with countless Apple hardware and software


    products over the years.  Better to let the Intels and Microsofts of the world underestimate what


    Apple is doing.  By the time they "get it," it will be too late for them to catch up.


     


    For example, the MacBook Air was originally slow and expensive.  Now it's reasonably fast and 


    reasonably priced, the 11.6" MacBook Air being Apple's cheapest Mac.  Intel has dumped $300 million


    into the Ultrabook Initiative to help PC OEMs clone the MacBook Air profitably.  No joy.


     


    And the little old "Rip. Mix. Burn." iTunes gradually evolved into a media and app juggernaut that


    drives Apple's hardware sales.  How many wannabes have attempted to copy iTunes?  


    Tons.  Most of them far too late.  Because Apple gradually evolved iTunes while everyone else


    was focused on cutting corners.


     


    The media love a crisis.  Especially online media, who have fallen into the click-bait trap just like


    everyone else.  We won't hear much about OS X and its technology until Windows hits the wall


    in the post-PC era.  And even then, we'll only hear things like "Meanwhile, Apple has managed to


    keep the Mac relevant in the post-PC era by intelligently improving OS X."  

  • Reply 14 of 32
    Anybody know if current apps need to be updated to take advantage of App Nap? Lightroom and Photoshop are brutal on my battery life.
  • Reply 15 of 32
    Anybody know if current apps need to be updated to take advantage of App Nap? Lightroom and Photoshop are brutal on my battery life.

    I think, if I remember correctly from the keynote, that it is a part of the OS and you get the basic parts for free. App developers can do other, more advanced, things to improve the AppNap feature; but in the end you get something for the cost of the upgrade.
  • Reply 16 of 32
    antkm1antkm1 Posts: 1,441member

    Quote:

    Originally Posted by SockRolid View Post


    For example, the MacBook Air was originally slow and expensive.  Now it's reasonably fast and 


    reasonably priced, the 11.6" MacBook Air being Apple's cheapest Mac.  Intel has dumped $300 million


    into the Ultrabook Initiative to help PC OEMs clone the MacBook Air profitably.  No joy.


     



    Actually the Mac Mini is "Apple's cheapest Mac" at $599

  • Reply 17 of 32
    antkm1antkm1 Posts: 1,441member


    Does anyone on here know if these new features are limited to SSD-based Macs or available to all Macs qualified to run Maveriks?


    I just bought my MBP 13" in January (HDD, non-retina) and "Power Nap" was excluded from my OS because Apple claims those types of features were limited to only SSD-Based Macs.  Was a bummer to read that from Apple's own site and I fear the same will be true with these features.

  • Reply 18 of 32
    irelandireland Posts: 17,571member
    2013 Air running Mavericks GM? Battery life?
  • Reply 19 of 32
    correctionscorrections Posts: 1,334member
    antkm1 wrote: »
    Does anyone on here know if these new features are limited to SSD-based Macs or available to all Macs qualified to run Maveriks?
    I just bought my MBP 13" in January (HDD, non-retina) and "Power Nap" was excluded from my OS because Apple claims those types of features were limited to only SSD-Based Macs.  Was a bummer to read that from Apple's own site and I fear the same will be true with these features.

    Yes, App Nap & Compressed Memory actually help HDD systems even more because avoiding disk use with a mechanical drive is even more important.
  • Reply 20 of 32
    irelandireland Posts: 17,571member
    slurpy wrote: »
    My friend installed mavericks on his new Air, and it was giving him battery life estimates of 15 hrs. Utterly insane. The people that bitch about Apple's lack of innovation miss the innovations in front of their eyes, hundreds of which are required to make such a thin laptop with by far the best battery life in the industry. That's innovation with direct benefit to every single user. 

    Hear hear.
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