MacBook Air 2013: Power Efficient To The Core(s)

An ultra-thin notebook computer that can run all day without a plug is finally a reality.


By Cary Chin
Last month, we looked at the initial announcement at WWDC of the latest MacBook Air laptops. These new machines are physically nearly identical to their predecessors, boast negligible performance improvements (and even performance degradation in some instances), cost about the same, and yet in my view are perhaps the most revolutionary products since the MacBook Air line was reinvented back in 2010. So what’s the big thing with this year’s refresh of the MacBook Air? Power efficiency!

That’s right—these new systems start with new Haswell ULT CPU’s (Intel Core i5/i7 22nm dual-core processors with voltage and frequency scaling), and extend the power saving features all the way through the system design (low base clock frequency, faster SSD and graphics) and the OS (Mac OS X 10.9, Mavericks, with aggressive hardware sleep functions) to produce an astounding jump of 70% to 80% in energy efficiency through to the end user. For those interested in the gory detail of the hardware and benchmarks, I recommend Anand Shimpi’s article at AnandTech.

The graph of battery life based on levels of workload (based on data collected at AnandTech) starts to give some insight into the changes in energy efficiency of the last two generations of MacBook Airs. Under “light” usage, the 2013 systems show the maximum improvement in battery life, with the advantage shrinking as the workload increases. This is consistent with a theoretical optimum system, where total energy usage is proportional with the work being performed. Of course, fixed energy costs (display and other system functions) will impact the actual numbers, but the goal always has been to bring fixed costs as close to zero as possible. Even more significantly, the new systems do indeed seem to live up to Apple’s claim of a battery that lasts “all day long.” With moderate use, making it through a full workday without a recharge is finally within reach.

One of the big contributing factors in the current rise in popularity of tablets is their ability to get through the day without a charge. But many are finding that a Bluetooth keyboard is a required accessory for many business applications. With the level of energy efficiency displayed by this new generation of laptop computers, the choice between a fully-functioning laptop and a tablet/keyboard combination will remain interesting for some time. We’re now seeing laptops with smartphone and tablet-like power management, and that’s all good for the consumer.

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