Mavericks Preview: Timer Coalescing boosts Mac laptop battery life

A lot of the time your CPU isn't doing anything, and we're not just talking about when you're away from your keyboard - even when you're working, the CPU could be powered down but isn't. OS X Mavericks will use a technique called Timer Coalescing to make the most of this downtime, and that means battery life will last much longer.

Of the many advanced technologies being introduced in OS X Mavericks, one of the most useful for Mac laptop users is Timer Coalescing. 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.

Here's what Apple says{.nofollow} about Timer Coalescing:

In OS X Mavericks, Timer Coalescing groups low-level operations together, creating tiny periods of idle time that allow your CPU to enter a low-power state more often.

Managing CPU traffic

In the space of a few seconds, your CPU will spike in activity many times. 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.

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 be. That's because many of those low-level operations are spread apart, over milliseconds, but it adds up pretty quickly.

Mavericks Preview: Timer Coalescing idle

Timer Coalescing changes that by grouping together those operations, so instead of constantly flickering between an idle state and operation, the CPU stays idle 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 less power. A lot less power.

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.

Mavericks Preview: CPU usage

The way Timer Coalescing works, 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 Mavericks.

Apple has a nifty interactive graphic on its web site{.nofollow} that will show you how Timer Coalescing works.

I don't know a single Mac laptop user who doesn't wish their device didn't last longer on a single charge. And in fairness to Apple, nothing they can do will make the battery last long enough for everyone. But Timer Coalescing goes a long way to improving battery life without negatively impacting system performance - I think we can all agree that it's a huge step forward.

Is Timer Coalescing an important feature for you? Have you used other operating systems (like Windows 7) that support Timer Coalescing? Let us know what you think in the comments, and click these links for more Mavericks info!

Peter Cohen
Latest in Apple Macos
macOS Sequoia
Here's how to use Window Tiling on macOS Sequoia
Stage Manager running Safari on a MacBook Air
Safari Technology Preview 200 launches with these improvements
Turn off click to reveal desktop macOS Sonoma
This Mac trick lets you quickly access your desktop from anywhere — become a Mac window ninja by mastering this feature
macOS Sequoia
How to use iPhone Mirroring on macOS Sequoia
Windows 11 on Mac with Parallels
CrowdStrike confirms Macs are 'not impacted' by a global outage impacting airlines, banks, and more — and a fix is on the way
macOS Sequoia
I've been using iPhone Mirroring on macOS Sequoia for 24 hours — it's one of the best features we've seen on Mac in a long time
Latest in News
iMore Logo
One more thing… Goodbye from iMore
Jony Ive
Jony Ive’s OpenAI hardware device could be his next world-changing design
NEBULA Cosmos 4K SE with Apple TV
This new 4K projector is tempting me to replace my LG C2 TV, just so I can watch Slow Horses on a 200-inch display
VisionOS 2 app reorganization
visionOS 2 is the first major software update for Apple Vision Pro, and now it's available
macOS Sequoia
macOS Sequoia (version 15) is now available for your Mac with some big upgrades
watchOS 11
watchOS 11 is now rolling out to all Apple Watch users with the Series 6 or newer