7. A9 chip with M9 motion co-processor
The new A9 processor allows the iPhone 6s and iPhone 6s Plus to run much faster. It improves the CPU performance by 70% and GPU by 90%. Screen animations are quick and smooth, app switching is done by the blink of an eye. Furthermore, the M9 motion co-processor also improves performance and allows extra features such as always-on Siri and more detailed motion metrics. The M9 chip can measure steps, distance, elevations and even your walking pace.