After revelations last month that Apple chose to use two different A9 chip fabrications in its new iPhone 6s models, a number of benchmarking tests have surfaced to suggest that the TSMC variant may offer longer battery life than its Samsung counterpart. A new report by MacRumors, however, suggests that many of these tests may have overestimated the impact of the larger Samsung chip on battery life under real-world conditions.
Many of the initial tests were run using “synthetic Geekbench tests” that were specifically designed to push the devices to their limits, running the CPUs at maximum power, and although in these scenarios differences of up to 22 percent were observed, another test where Austin Evans ran YouTube videos on different devices revealed only a one percent difference in battery drain. Another video from Jonathan Morrison revealed minor battery life differences between the TSMC and Samsung iPhones. It does appear the TSMC chip performs slightly better even in these tests, but it’s hard to quantify just how much of a difference it will make in real world use of the iPhones.
Update: Apple has released a statement to TechCrunch, castigating artificial tests that don’t represent real-world usage as misleading, and noting that the company’s own data shows variations of two to three percent, even when accounting for “variable component differences” which likely include not only the different A9 processors but possibly other components which may vary between devices.
Certain manufactured lab tests which run the processors with a continuous heavy workload until the battery depletes are not representative of real-world usage, since they spend an unrealistic amount of time at the highest CPU performance state. It’s a misleading way to measure real-world battery life. Our testing and customer data show the actual battery life of the iPhone 6s and iPhone 6s Plus, even taking into account variable component differences, vary within just 2-3% of each other.