Timer Coalescing Improves Mac Battery Life In Mavericks

Of the many advanced technologies being introduced in OS X Mavericks, one of the most useful, for Mac laptop users, is the new Timer Coalescing feature.  It’s an energy-saving technique that promises to extend battery life on your MacBook, by forcing the laptop’s CPU into a low-power mode whenever it’s available.  OS X will use this technique to make the most of your CPU downtime, and that means battery life will last much longer.  A lot of the time your CPU isn’t doing anything, not just when you’re away from your keyboard etc, this even happens when you’re working.



Managing The CPU
In the space of a few seconds, your CPU will spike in activity many times. This is not only because of the different applications you’re running, but also because of all the other housekeeping tasks needed to keep the OS running.  In between those moments, your Mac’s CPU enters an idle state, where it’s not doing much. 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. Currently in Mountain Lion and earlier revisions of OS X, your Mac isn’t doing this efficiently. In essence, that means that power is getting wasted, and your Mac laptop is draining its battery faster than it should to be. That’s because many of those low-level operations are spread apart, over milliseconds, but it adds up pretty quickly.  Timer Coalescing changes that by grouping together those operations, so instead of constantly flickering between an idle state and operation, the CPU stays idle for longer. It may only stay idle for a fraction of a second, compared to a few milliseconds, but over minutes and hours, that idle state adds up. The net result is that your Mac’s CPU uses a great deal less power.
In testing, 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 a staggering 72 percent!  The way Timer Coalescing works means you won’t notice any difference in performance. The operating system is just grouping together the tasks that need to happen to make it run more efficiently. And there’s nothing you need to do to get it working, it’s built right in to the OS.  However, Apple has a nifty interactive graphic on its web site that will show you how Timer Coalescing works.
We all want a longer lasting battery life and a longer lasting charge and this neat new feature will make some headway into these issues.  Well done Apple!