IPhone 6S

Hardware

The iPhone 6S is nearly identical in design to the iPhone 6. In response to the "bendgate" design flaws of the previous model, changes were made to improve the durability of the chassis: the 6S was constructed from a stronger, 7000 series aluminum alloy, "key points" in the rear casing were strengthened, and touchscreen Integrated circuits were re-located to the display assembly. Alongside the existing gold, silver, and space gray options, a new rose gold color option was also introduced.

The iPhone 6S is powered by the Apple A9 system-on-chip, which the company stated is up to 70% faster than Apple A8, and has up to 90% better graphics performance. The iPhone 6S has 2 GB of RAM, more than any previous iPhone, and also supports LTE Advanced. The Touch ID sensor on the 6S was also updated, with the new version having improved fingerprint scanning performance over the previous version.

While the capacities of their batteries are slightly smaller, Apple rates iPhone 6S and 6S Plus as having the same average battery life as their respective predecessors. The A9 system-on-chip was dual-sourced from TSMC and Samsung. Although it was speculated that the Samsung version had worse battery performance than the TSMC version, multiple independent tests have shown there is no appreciable difference between the two chips. Although the device is not promoted as such, the iPhone 6S has a degree of water resistance because of a change to its internal design, which places a silicone seal around components of the logic board to prevent them from being shorted by accidental exposure to water.

Their displays are the same sizes as those of the iPhone 6, coming in 4.7-inch 750p and 5.5-inch 1080p (Plus) sizes. The iPhone 6S features a technology known as 3D Touch; sensors are embedded in the screen's backlight layer that measure the firmness of the user's touch input by the distance between it and the cover glass, allowing the device to distinguish between normal and more forceful presses. 3D Touch is combined with a Taptic Engine vibrator to provide associated haptic feedback. Although similar, this is distinct from the Force Touch technology used on the Apple Watch and Retina MacBook, as it is more sensitive and can recognize more levels of touch pressure than Force Touch. Due to the hardware needed to implement 3D Touch, the iPhone 6S is heavier than its predecessor.

The iPhone 6S features a 12-megapixel rear-facing camera, an upgrade from the 8-megapixel unit on previous models, as well as a 5-megapixel front-facing camera. It can record 4K video, as well as 1080p video at 60 and now 120 frames per second.

The iPhone 6S and 6S Plus were originally offered in models with 16, 64, and 128 GB of internal storage. Following the release of iPhone 7 in September 2016, the 16 and 64 GB models were dropped, and replaced by a new 32 GB option. For improved storage performance, iPhone 6S utilizes NVM Express (NVMe), resulting in a maximum average read speed of 1,840 megabytes per second.

Software

The iPhone 6S ships with iOS 9; the operating system leverages the 3D Touch hardware to allow recognition of new gestures and commands, including "peeking" at content with a light touch and "popping" it into view by pressing harder, and accessing context menus with links to commonly used functions within apps with harder presses on home screen icons. The camera app's "Retina Flash" feature allows the display's brightness to be used as a makeshift flash on images taken with the front camera, while "Live Photos" captures a short video alongside each photo taken.

Reception

The Verge described the 6S, in particular the Plus model, as "right now the best phone on the market...There just aren't other companies that can roll out a feature like 3D Touch and make it work in a way that suggests the creation of entirely new interface paradigms, and every other phone maker needs to figure out exactly why Apple's cameras are so consistent before they can really compete." The Guardian commented that the phone "has the potential to be the best smaller smartphone on the market, but its short battery life is deeply frustrating" and described the camera as "not leagues ahead of the competition anymore."

The Register praised performance, noting that "we’re now using phones with the performance of current PCs," but described 3D Touch as "just a glorified vibrator" and "no good...it's not binary...and you still don’t know quite what’s going to happen until you try." AnandTech awarded the iPhone 6S and 6S Plus its second ever Editor's Choice Gold Award for a phone, based largely on the phone's performance and the addition of 3D Touch. An additional topic noted by journalists around the same time has been the better rate of security updates on iPhones compared to Android phones, with 90 percent of Android phones running insecure and outdated versions.

Record launch sales

On the Monday following the iPhone 6S' launch weekend, Apple announced that they had sold 13 million models, a record-breaking number that exceeded the 10 million launch sales of the iPhone 6 in 2014.

First ever iPhone sales decline

In the months following the launch of the iPhone 6S and 6S Plus, Apple saw its first ever quarterly year-over-year decline in iPhone sales, attributed to a saturated smartphone market in Apple's biggest sales countries and consumers in developing countries not buying iPhones.

Unexpected battery shutdowns

In November 2016, Apple announced that a "very small number" of iPhone 6S devices manufactured between September and October 2015 have faulty batteries that unexpectedly shut down. While Apple noted that the battery problems were "not a safety issue", it announced a battery replacement program for affected devices. Customers with affected devices, which span "a limited serial number range", were able to check their device's serial number on Apple's website, and, if affected, receive a battery replacement free of charge at Apple Stores or authorized Apple Service Providers.

In December 2016, Apple revealed new details about the issue, stating that the affected devices contained a "battery component that was exposed to controlled ambient air longer than it should have been before being assembled into battery packs". The statement also said that customers "outside of the affected range" may also experience unexpected shutdowns, though clarifying that some shutdowns can occur under "normal conditions" because the iPhone tries to "protect its electronics". Apple also said that an upcoming update to the iOS operating system would include additional diagnostic tools to help Apple find more information about different kinds of battery issues.

In February 2017, Apple released a statement to TechCrunch, saying that the iOS 10.2.1 update, released on January 23, had reduced the occurrence of battery shutdowns by "more than 80%" on iPhone 6S devices. In full, the statement read:

With iOS 10.2.1, Apple made improvements to reduce occurrences of unexpected shutdowns that a small number of users were experiencing with their iPhone. iOS 10.2.1 already has over 50% of active iOS devices upgraded and the diagnostic data we've received from upgraders shows that for this small percentage of users experiencing the issue, we're seeing a more than 80% reduction in iPhone 6s and over 70% reduction on iPhone 6 of devices unexpectedly shutting down. We also added the ability for the phone to restart without needing to connect to power, if a user still encounters an unexpected shutdown. It is important to note that these unexpected shutdowns are not a safety issue, but we understand it can be an inconvenience and wanted to fix the issue as quickly as possible. If a customer has any issues with their device they can contact AppleCare.