Apple silicon

Apple silicon is a series of system on a chip and system in a package processors designed by Apple Inc., mainly using the ARM architecture. They are used in nearly all of the company's devices including Mac, iPhone, iPad, Apple TV, Apple Watch, AirPods, AirTag, HomePod, and Apple Vision Pro.
The first Apple-designed system-on-a-chip was the Apple A4, which was introduced in 2010 with the first-generation iPad and later used in the iPhone 4, fourth generation iPod Touch and second generation Apple TV.
Apple announced its plan to switch Mac computers from Intel processors to its own chips at WWDC 2020 on June 22, 2020, and began referring to its chips as Apple silicon. The first Macs with Apple silicon, built with the Apple M1 chip, were unveiled on November 10, 2020. The Mac lineup completed its transition to Apple chips in June 2023.
Apple fully controls the integration of Apple silicon in the company's hardware and software products. Johny Srouji, the senior vice president for Apple's hardware technologies, is in charge of the silicon design. Apple is a fabless manufacturer; production of the chips is outsourced to contract foundries including TSMC and Samsung.

''A''-series SoCs

The A series is a family of SoCs used in the iPhone, certain iPad models, and the Apple TV. A-series chips were also used in the discontinued iPod Touch line and the original HomePod. They integrate one or more ARM-based processing cores, a graphics processing unit, cache memory and other electronics necessary to provide mobile computing functions within a single physical package.

Apple A4

The Apple A4 is a PoP SoC manufactured by Samsung, the first SoC Apple designed in-house. It combines an ARM Cortex-A8 CPU also used in Samsung's S5PC110A01 SoC and a PowerVR SGX 535 graphics processor, all built on Samsung's 45-nanometer silicon chip fabrication process. The design emphasizes power efficiency. The A4 commercially debuted in 2010, in Apple's iPad tablet, and was later used in the iPhone 4 smartphone, the fourth-generation iPod Touch, and the 2nd-generation Apple TV.
The Cortex-A8 core used in the A4, dubbed Hummingbird, is thought to use performance improvements developed by Samsung in collaboration with chip designer Intrinsity, which was subsequently acquired by Apple It can run at far higher clock rates than other Cortex-A8 designs yet remains fully compatible with the design provided by ARM. The A4 runs at different speeds in different products: 1 GHz in the first iPads and 2nd-generation Apple TV, and 800 MHz in the iPhone 4 and fourth-generation iPod Touch.
The A4's SGX535 GPU could theoretically push 35 million polygons per second and 500 million pixels per second, although real-world performance may be considerably less. Other performance improvements include additional L2 cache.
The A4 processor package does not contain RAM, but supports PoP installation. The 1st-generation iPad, fourth-generation iPod Touch, and the 2nd-generation Apple TV have an A4 mounted with two low-power 128 MB DDR SDRAM chips, while the iPhone 4 has two 256 MB packages for a total of 512 MB. The RAM is connected to the processor using ARM's 64-bit-wide AMBA 3 AXI bus. To give the iPad high graphics bandwidth, the width of the RAM data bus is double that used in previous ARM11- and ARM9-based Apple devices.

Apple A5

The Apple A5 is an SoC manufactured by Samsung that replaced the A4. The chip commercially debuted with the release of Apple's iPad 2 tablet in March 2011, followed by its release in the iPhone 4S smartphone later that year. Compared to the A4, the A5 CPU "can do twice the work" and the GPU has "up to nine times the graphics performance", according to Apple.
The A5 contains a dual-core ARM Cortex-A9 CPU with ARM's advanced SIMD extension, marketed as NEON, and a dual core PowerVR SGX543MP2 GPU. This GPU can push between 70 and 80 million polygons/second and has a pixel fill rate of 2 billion pixels/second. The iPad 2's technical specifications page says the A5 is clocked at 1 GHz, though it can adjust its frequency to save battery life. The clock speed of the unit used in the iPhone 4S is 800 MHz. Like the A4, the A5 process size is 45 nm.
An updated 32 nm version of the A5 processor was used in the third-generation Apple TV, the fifth-generation iPod Touch, the iPad Mini, and the new version of iPad 2. The chip in the Apple TV has one core locked. Markings on the square package indicate that it is named APL2498, and in software, the chip is called S5L8942. The 32 nm variant of the A5 provides around 15% better battery life during web browsing, 30% better when playing 3D games and about 20% better battery life during video playback.
In March 2013, Apple released an updated version of the 3rd-generation Apple TV containing a smaller, single-core version of the A5 processor. Unlike the other A5 variants, this version of the A5 is not a PoP, having no stacked RAM. The chip is very small, just 6.1×6.2 mm, but as the decrease in size is not due to a decrease in feature size, this indicates that this A5 revision is of a new design. Markings tell that it is named APL7498, and in software, the chip is called S5L8947.

Apple A5X

The Apple A5X is an SoC announced on March 7, 2012, at the launch of the third-generation iPad. It is a high-performance variant of the Apple A5; Apple claims it has twice the graphics performance of the A5. It was superseded in the fourth-generation iPad by the Apple A6X processor.
The A5X has a quad-core graphics unit instead of the previous dual-core as well as a quad-channel memory controller that provides a memory bandwidth of 12.8 GB/s, roughly three times more than in the A5. The added graphics cores and extra memory channels add up to a very large die size of 165 mm², for example twice the size of Nvidia Tegra 3. This is mainly due to the large PowerVR SGX543MP4 GPU. The clock frequency of the dual ARM Cortex-A9 cores have been shown to operate at the same 1 GHz frequency as in A5. The RAM in A5X is separate from the main CPU package.

Apple A6

The Apple A6 is a PoP SoC introduced on September 12, 2012, at the launch of the iPhone 5, then a year later was inherited by its minor successor the iPhone 5C. Apple states that it is up to twice as fast and has up to twice the graphics power compared to its predecessor the Apple A5. It is 22% smaller and draws less power than the 45 nm A5.
The A6 is said to use a 1.3 GHz custom Apple-designed ARMv7 based dual-core CPU, called Swift, rather than a licensed CPU from ARM like in previous designs, and an integrated 266 MHz triple-core PowerVR SGX 543MP3 graphics processing unit. The Swift core in the A6 uses a new tweaked instruction set, ARMv7s, featuring some elements of the ARM Cortex-A15 such as support for the Advanced SIMD v2, and VFPv4. The A6 is manufactured by Samsung on a high-κ metal gate 32 nm process.

Apple A6X

Apple A6X is an SoC introduced at the launch of the fourth-generation iPad on October 23, 2012. It is a high-performance variant of the Apple A6. Apple claims the A6X has twice the CPU performance and up to twice the graphics performance of its predecessor, the Apple A5X.
Like the A6, this SoC continues to use the dual-core Swift CPU, but it has a new quad core GPU, quad channel memory and slightly higher 1.4 GHz CPU clock rate. It uses an integrated quad-core PowerVR SGX 554MP4 graphics processing unit running at 300 MHz and a quad-channel memory subsystem. Compared to the A6 the A6X is 30% larger, but it continues to be manufactured by Samsung on a high-κ metal gate 32 nm process.

Apple A7

The Apple A7 is a 64-bit PoP SoC whose first appearance was in the iPhone 5S, which was introduced on September 10, 2013. The chip would also be used in the iPad Air, iPad Mini 2 and iPad Mini 3. Apple states that it is up to twice as fast and has up to twice the graphics power compared to its predecessor the Apple A6. The Apple A7 chip is the first 64-bit chip to be used in a smartphone and later a tablet computer.
The A7 features an Apple-designed 1.3–1.4 GHz 64-bit ARMv8-A dual-core CPU, called Cyclone, and an integrated PowerVR G6430 GPU in a four cluster configuration. The ARMv8-A architecture doubles the number of registers of the A7 compared to the A6. It now has 31 general-purpose registers that are each 64-bits wide and 32 floating-point/NEON registers that are each 128-bits wide. The A7 is manufactured by Samsung on a high-κ metal gate 28 nm process and the chip includes over 1 billion transistors on a die 102 mm² in size.

Apple A8

The Apple A8 is a 64-bit PoP SoC manufactured by TSMC. Its first appearance was in the iPhone 6 and iPhone 6 Plus, which were introduced on September 9, 2014. A year later it would drive the iPad Mini 4. Apple states that it has 25% more CPU performance and 50% more graphics performance while drawing only 50% of the power compared to its predecessor, the Apple A7. On February 9, 2018, Apple released the HomePod, which is powered by an Apple A8 with 1 GB of RAM.
The A8 features an Apple-designed 1.4 GHz 64-bit ARMv8-A dual-core CPU, and an integrated custom PowerVR GX6450 GPU in a four cluster configuration. The GPU features custom shader cores and compiler. The A8 is manufactured on a 20 nm process by TSMC, which replaced Samsung as the manufacturer of Apple's mobile device processors. It contains 2 billion transistors. Despite that being double the number of transistors compared to the A7, its physical size has been reduced by 13% to 89 mm².

Apple A8X

The Apple A8X is a 64-bit SoC introduced at the launch of the iPad Air 2 on October 16, 2014. It is a high performance variant of the Apple A8. Apple states that it has 40% more CPU performance and 2.5 times the graphics performance of its predecessor, the Apple A7.
Unlike the A8, this SoC uses a triple-core CPU, a new octa-core GPU, dual channel memory and slightly higher 1.5 GHz CPU clock rate. It uses an integrated custom octa-core PowerVR GXA6850 graphics processing unit running at 450 MHz and a dual-channel memory subsystem. It is manufactured by TSMC on their 20 nm fabrication process, and consists of 3 billion transistors.