Apple Introduces the A9 and 3D Touch

Apple announced the iPhone 6s and 6s Plus on September 9, 2015, introducing the A9 processor and 3D Touch. The A9 was co-manufactured by both TSMC (16nm FinFET) and Samsung (14nm FinFET) — an unusual dual-source arrangement that caused public concern about performance differences between the two variants, though Apple stated the real-world gap was within a few percent. The A9 carried approximately 2 billion transistors, two high-performance CPU cores clocked at 1.85 GHz, and a six-core PowerVR GT7600 GPU. Compared to the A8, Apple claimed 70% faster CPU performance and 90% faster GPU performance while using the same battery size.

3D Touch added a layer of capacitive sensors beneath the display that could measure the force of a press in addition to its position. The Taptic Engine — a linear actuator with higher fidelity than a rotary vibration motor — gave immediate haptic feedback calibrated to the press depth, creating a physical sensation of clicking or resistance. Apple defined two interaction levels: Peek (a light press to preview content without navigating away) and Pop (a deeper press to open it fully). Developers could add Peek/Pop to their apps via the UIViewControllerPreviewingDelegate API and add Quick Actions to the home screen icon via UIApplicationShortcutItem — for example, the Camera icon offered shortcuts to selfie, video, slow-mo, and photo without opening the app.

Despite critical praise for the engineering, 3D Touch never became a widely understood interaction pattern. Discoverability was the core problem: there was no visual affordance indicating which elements responded to pressure. User research and App Store analytics consistently showed that most iPhone 6s owners never discovered many 3D Touch features. Apple removed 3D Touch hardware with the iPhone XR (2018), replaced it with Haptic Touch (a long-press triggering the same UI actions via software timer) across the whole lineup from 2019, and iOS 13 backfilled the long-press behavior onto older iPhones. The Taptic Engine survived and improved in subsequent models; the pressure-sensing layer did not.

Why This Moment Mattered

The event is useful to read as a platform signal, not only as a product announcement. In the short term, it gave users and developers something concrete to react to. In the longer term, it became part of a larger pattern in hardware, computing, history: hardware, software, services, and user expectations were all changing at the same time.

A good technology milestone usually matters for more than one audience. Enthusiasts notice the specifications or the interface first. Developers ask what new assumptions they can make. Companies look at cost, compatibility, and strategy. Ordinary users mostly notice whether the result makes their devices faster, easier, safer, or more useful.

The Broader Context

This period of computing was shaped by several overlapping transitions: faster networks, more capable mobile devices, cloud infrastructure, stronger security expectations, and software that changed continuously after release. Against that background, the milestone was not an isolated headline. It was one piece of a much larger movement away from static products and toward connected platforms.

That context helps explain why some announcements that looked modest at the time became important later. A browser feature, processor change, development tool, or platform policy can alter what future products are able to assume. Once enough users, developers, and vendors adapt, the new assumption becomes normal.

Looking Back

The value of revisiting the moment is that it shows how technology history is built from many medium-sized steps. Some are celebrated immediately, while others become meaningful only after the ecosystem catches up.

Looking back also keeps the story balanced. Progress usually brings tradeoffs: performance against power use, openness against consistency, convenience against control, and speed against stability. The most interesting milestones are the ones that reveal those tradeoffs clearly. This one belongs in that category because it helps explain not just what changed, but why the direction of computing kept moving the way it did.