Apple’s Big Breakthrough

Power-efficient software arrives at WWDC 2013; software and hardware now share same goal.


By Cary Chin
For literally years now, we’ve talked about and measured energy consumption as smartphones have morphed from primarily communications devices (voice), to the world’s most widespread computing platform, and back again to a communications focus. But this time it’s data communications, and voice calls are just a small subset.

Smartphones themselves, once the defining standard bearer of the Mobile Electronics category, have begun to mature, and new sub-categories, from “wearable” (Google Glass, Nike FuelBand, Pebble Watch, iWatch?) to “rideable” (Tesla Model S & Roadster, Nissan Leaf, Toyota Prius, etc.), have zoomed to the forefront. But two common properties still tie the entire Mobile/Portable Electronics spectrum together: They all depend on software for their whiz-bang features, and none have long enough battery life. We’ve noted the difficulty in linking new low-power hardware features through the many layers of software to create a development environment in which we can even begin to measure the energy efficiency of application software, let alone start to optimize it. But all of that is starting to change.

At this week’s Apple Worldwide Developers Conference (WWDC)—a conference for software developers for iOS and OS X, power and energy efficiency also took center stage in some interesting ways. As is often the case, Apple announced some hardware refreshes, including new MacBook Airs with an eye-popping increase in energy efficiency. With the same battery capacity (35Wh for 11” model, 50Wh for the 13”) since the fully redesigned line was introduced in 2010, the MacBook Airs introduced this week claim a 70% to 80% increase in energy efficiency, from 5 hours to 9 hours of “wireless Web” usage on the 11-inch, and from 7 hours to 12 hours on the 13-inch.

The new mobile Haswell-ULT processors are optimized for low power, but it’s hard to believe that hardware changes alone could produce the incredible jump in energy efficiency. The answer was in the announcement for Mac OS X “Mavericks.” Now at version 10.9, Mac OS X has gone through many generations, but I don’t recall any version (or any major OS release ever) whose primary focus was “battery life.” Batteries are hardware, aren’t they? Mavericks optimizes energy efficiency by reducing CPU use by up to 72% using “Timer Coalescing” (intelligent and aggressive sleep modes), and together with optimizations in Safari targets “power-hungry” Web sites. A new “App Nap” feature shuts off CPU activity when a window is unseen in the background.

These all sound analogous to hardware-related optimizations to me. But the optimization of power and energy at a software-application level is great to see, and signals that we’re finally moving down the path of energy efficiency at the complete system level, including the OS and application software. Hallelujah!

It’s the hardware. It’s the software. Finally, we’ve come to realize that it’s not a matter of who comes out on top, but of “playing well together.”

—Cary Chin is director of marketing for low-power solutions at Synopsys.

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