A few days ago, it was revealed that the A9 chip in Apple's new iPhone 6s is manufactured by two different companies, Samsung and Taiwan Semiconductor Manufacturing Co (TSMC). More notably, reports started circulating that the battery life in the Samsung A9 devices was notably worse than that of the TSMC iPhones. Some tests have revealed that the TSMC chips last as much as two hours longer than the phones with Samsung silicon inside. Now, Apple has issued an official response that downplays the difference as only a matter of a few percentage points.

http://www.engadget.com/2015/10/08/a...or-variations/