Apple's A-Series SoCs
Over the past few years, Apple demonstrated an increasing desire to create its own custom SoC hardware, tuning architecture, differentiating functionality, and optimizing for cost.
Apple A-Series
Until the iPad and iPhone 4, Apple only used off-the-shelf SoCs from other companies. At that point, however, it began adding more customization. The CPU and GPU were still reference (800 MHz Cortex-A8 and PowerVR SGX535). However, Apple implemented technology around those complexes to improve battery life.
In 2011, the following year, Apple shipped the A5 SoC in its iPad and iPhone. Also designed by Apple (naturally), the A5 employed a dual-core 1 GHz Cortex-A9 CPU and PowerVR SGX543MP2 graphics engine that were much faster that their predecessors and could handle higher resolutions much better.
The third-gen iPad emerged in 2012 with an Apple A5X. It was almost identical to the A5 but had twice as many GPU cores. Therefore, in graphics-bound titles, it was up to two times as fast. Apple's newer GPU was nevertheless unable to properly handle the iPad's Retina screen. Even though it was twice as powerful, the new iPad had four times as many pixels, requiring even more performance to match its predecessor. So, later that same year, Apple introduced the iPad 4 with an A6X SoC that not only quadrupled the A5's graphics potential, but also included a proprietary dual-core “Swift” host processor running at 1.3 GHz. In a great many cases, it was faster than the competition. That was a first for Apple. Up until then, the company tended to go conservative with its host processor, preferring to favor long battery life, which invariably led to weaker benchmark results.
Apple A7
The A7 took everyone off-guard, especially competing SoC-makers. No one was expecting a CPU based on the ARMv8 instruction set to arrive for at least another year. But Apple released one in late 2013.
Even now, Qualcomm, the mobile chip leader, doesn’t have its own ARMv8-based architecture. Its only imminent releases involve off-the-shelf Cortex-A53 configurations bearing Snapdragon branding and the Snapdragon 808 and 810, which will utilize off-the-shelf Cortex-A57 cores. Only Nvidia is supposed to ship its Denver CPU this year, and Samsung may or may not release an Exynos chip based on Cortex-A57.
Nobody really knows how Apple managed to design and ship an ARMv8 chip so quickly. But it did, and is milking the marketing for all it's worth by claiming to offer the first desktop-class 64-bit chip for its phones and tablets. Competing processor companies were forced to scramble and promise their own 64-bit devices as soon as possible, too.
Unlike Swift, which is similar to Qualcomm's Krait, the Cyclone architecture is much wider, managing to handle up to six instructions at once (compared to three for Krait and Swift). In the real world, or at least in benchmarks, that seems to translate to roughly 50%-higher performance versus Swift at the same 1.3 GHz frequency.
With the 64-bit Cyclone, Apple showed all chip makers, including Intel, that it's serious about making powerful processors.