There was only one real surprise when iFixit.com did its by-now ritual teardown of the new iPhone 5. The phone sports a 1440 milliamp-hour battery just a hair bigger than the battery in the iPhone 4S. Yet despite going to a bigger display, boosting processor performance, and using faster but more power-hungry LTE wireless, the new phone seems to deliver about the same battery life as its predecessor. And instead of having to go to a bigger battery, Apple was able to use improvements in case and display design to reduce the iPhone’s thickness and weight markedly.
This is the result of obsessive engineering, not magic. Apple uses its control over every aspect of the iPhone’s design, from the silicon to the software, to fine-tune a device that squeezes maximum performance from minimal resources. This gives Apple an enormous advantage over all competitors save Research In Motion (whose severe problems are the result of its inability to read and respond to the changing market for BlackBerry, not its engineering.)
In his detailed examination of the iPhone 5, the redoubtable Anand Lal Shimpi found compelling evidence that the iPhone 5’s A6 system-on-chip uses custom, Apple-designed ARM processor cores. In previous A-series SOCs, Apple had customized Samsung ARM designs, mostly by pruning circuitry that the iPhone and iPad didn’t need. No USB ports or SD card slots, no need to have controllers for unused devices (its then nature of chips the even unused circuits increase the power draw, not by much but significantly in a design where every microwatt counts.) With the A6, Apple takes the customization a step further, achieving complete control over the heart of this system.
With a fully customized SOC, Apple could then fine-tune the software to wring out every microgram of performance while minimizing power consumption. Even the compiler used to generate iOS code can be tweaked to optimize apps’ power consumption and performance. The tradeoffs between battery size and run time are still there–even Apple cannot escape the laws of physics–but the terms of trade are improved dramatically.
There’s no way Android can match this. Google has to write code that can support a wide variety of SOCs, including those from NVIDIA, Qualcomm, Texas Instruments, and Samsung. Android devices use several graphics systems and provide support for assorted peripherals. Code designed to run on heterogeneous systems will never be as efficient as Apple’s singleminded approach. Things are somewhat better in the Windows Phone 8 world, where the initial offerings all use a Qualcomm Snapdragon SOC. We’ll see how that afffects battery life and performance when the phones ship.