Apple Introduces the A9 and 3D Touch

Apple introduced the A9 processor and 3D Touch with the iPhone 6s in September 2015. The A9 used Apple’s 64-bit ARM-compatible CPU design and delivered a large performance increase over the A8 while remaining within smartphone power limits.

3D Touch added pressure sensitivity to the display. Capacitive sensors could distinguish a normal touch from a firmer press, while the Taptic Engine provided precise haptic feedback. Apple used this for shortcuts such as “Peek” previews and “Pop” actions.

The feature was technically clever but never became a universal interaction language because users could not easily discover where pressure-sensitive actions existed. Apple eventually replaced it with long-press gestures, showing that hardware capability does not guarantee a successful interface convention.