OS X Mavericks’ Timer Coalescing boosts MacBook battery life – a lot

“Of the many advanced technologies being introduced in OS X Mavericks, one of the most useful for Mac laptop users is Timer Coalescing,” Peter Cohen reports for iMore. “It’s an energy-saving technique that promises to extend battery life on your Mac laptop by forcing the laptop’s CPU into a low-power mode whenever it’s available.”

“In the space of a few seconds, your CPU will spike in activity many times,” Cohen reports. “This is not only because of the applications you’re running, but also because of all the other housekeeping tasks needed to keep OS X up and running. In between those moments, your Mac’s CPU enters an idle state, where it’s not doing much of anything.”

Cohen reports, “To wake from that idle state requires power, and using power means the battery of your MacBook Air or MacBook Pro won’t last as long. And right now, in Mountain Lion and earlier revisions of OS X, your Mac isn’t doing it as efficiently as it could be. That means power is getting wasted, and your Mac laptop is draining its battery faster than it has to… In its tests, Apple compared Mountain Lion and a development build of Mavericks running on a production MacBook Air. They discovered that Timer Coalescing can reduce CPU activity by 72 percent.”

Read more in the full article here.


      1. Absolutely not.

        While the CPU uses a significant fraction of the power of a laptop, it is by far not the largest power hog.

        In some use cases the CPU uses less than 20% of the average power being drawn from the battery.

        If, indeed, the average power draw of the CPU can be reduced by *up to* 72%, I’d expect the average user to see on the order of 10% or so longer battery life in real world use. This is still a large jump forward. However, it is no where near a 24 hour (in use) battery life.

        1. They could get there with solar cells, and I believe they have patents and are working on a practical implementation, with a horizon of 2-3 years. Battery technology is being heavily researched by all the major players, and it’s obvious that distributed/embedded computing is the wave of the future. I just think that Apple saw this coming sooner, and took it more seriously, than the other players and thus holds an advantage. I’m not aware that tech analysts have spotted this trend quite yet.

          1. Even given solar cells with 100% conversion efficiency (about 70% above the state-of-the-art), you could not collect enough solar power on a laptop case to run an existing laptop. in the future, that might be possible. but, right now, embedded solar cells could only help to recharge a bit during idle times and supplement the battery a bit during active times. The drawback, of course, being that your laptop would have to be illuminated by the sun or a suitable artificial light source.

    1. Phil: There are several issues. Here is my brainstorm on the subject:

      1) Battery technology continues to be rather primitive. Thankfully demand, such as your’s, is pushing money into researching new battery tech.

      2) You could have a working week (120 hour) battery for your MacBook, but it would weigh a number of times more than it does now. The current MacBooks, aka MacBook Air, sells well specifically because it is remarkably light, among other reasons. Witness the ripoff ‘UltraBook’ efforts on the Windows box side of the computer business. The MacBook Air started a revolution. Weight took priority over battery life.

      3) Access to mains power continues to be nearly ubiquitous among MacBook users. If MacBook sales demand in 3rd world countries became a priority, we’d see other sources of power being used, such as solar, to keep the MacBook charged each day.

      With time, research in alternative energy is going to blossom. First we have to get out from under the olde world thumb of the carbon consumption branch of our Corporate Oligarchy. These money gathering morons are out of touch with the future and are quite literally hampering all energy research that they perceive as encroaching on their revenue stream. Don’t underestimate their detrimental effect on the current state of energy research. If they can’t suppress it, they buy it and bury it. That has been going on for several decades.

  1. Apple should not have announced this feature or talked about this at all. Should have let people discover it as a total surprise after launching Mavericks. Would have caught the rest of the industry (or should I say “Slavish Copiers”) totally off guard.

    1. This *I think* is not a feature the slavish copiers like samdung & giggle can copy.
      Remember samedung is using giggles craptastic pretend OS and giggle’s droid is done in JAVA (not a real core level OS).

      If the above are incorrect, someone please correct.

      MicrosSucksClown peebles could copy it but they would do it backwards and cost battery life.

      1. This is not the type of feature that Samsung would want to copy, too much work to create their own version.
        Besides, this isn’t the job of a box assembler, this would be Microsoft’s job. Good luck accomplishing that without control of hardware design.

            1. I’d love to hear your comparative analysis, especially since both systems are taking advantage of what’s built into Intel architecture to do this. But please, do explain.

            2. A variation of this is indeed in Windows 7

              Apple doesn’t have to invent EVERYTHING. But when Apple does emulate previously existing technology, they typically improve upon it and make it BETTER.

              Example: Microsoft put ASLR (Address Space Layout Randomization) security tech into Windows Vista, about a year before Apple caught on. But Microsoft’s version sucked and was easily defeated by hackers, one of the reasons Vista was infamous. Apple’s catch up version was considered meagre by comparison, except it actually WORKED and provided superior security vs Vista. Apple’s second attempt was even better, running ring’s around the ASLR version in Windows 7.

              And so on.

            3. That was the real kicker of the article. Never would have known it. Window 7 didn’t seem anymore energy efficient than XP – in fact it seemed little a bit worse. But I guess it could have been much worse without timer coalescing. Anyhow, that’s good news, because Microsoft can’t copy this if they already using it, and Apple is likely to have created a better implementation.

  2. This is a significant OS level change. It just shows the continual wisdom of Apple to kiss legacy stuff good bye and the decision for their kernel.

    Microsoft would have to program that into Windows if they wanted to compete. I bet it would take at least two years.

    I bet it takes about 2 years before they can come close.

    Hardware vendors will have to use much bigger batteries to even come close.

    With the new battery life your batteries last even longer with fewer charge cycles. Good for you, good for Apple and good for the environment.

    There will be blood over this.

    1. Timer Coalescing has been used since 2009, in Windows 7/Windows Server 2008. Reducing power consumption is a good thing for extending battery life, but is even better for networks of distributed workstations.

      1. How come you’re so au fait with the latest technological developments?

        And here I was thinking you were some sort of technology troglodyte, like me.

        1. You do yourself a disservice, I think. Cave dwellers specialised in survival, yet here you are, bravely curious and adventurous, trying to improve your mind. Which seems to be in excellent working order.

          1. Pssst…it’s me darlin’, BLN….

            MDN admin banned me from this site so I’ve had to use a nom de guerre…mucho love & kisses…from the Scarlet Pimpernel…;)

  3. The article says Timer Coalescing doesn’t speed up the processing, just lowers the idle state power. With lower average power, you would think they could overclock the CPU and get faster speeds too (either/or).

  4. My biggest gripe right now, MacBook Air running 10.8.5, is that there is MAJOR battery drain when the lid is closed and the computer is allegedly asleep.

    Wasn’t always like this. I believe it’s because “outsiders” (NSA or their ilk) have infested my computer for whatever trumped up reason they can come up with.

    I’ve gone thru Activity Monitor CPU usage, but there’s always been so much coded sierra in there unless one is a programer, one would have no idea what belongs and what doesn’t.

Reader Feedback

This site uses Akismet to reduce spam. Learn how your comment data is processed.