Mac transition to Apple silicon
Apple silicon ARM architecture family Universal 2 binary Rosetta 2 Developer Transition Kit
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Apple silicon refers to a series of system on a chip (SoC) and system in a package (SiP) processors designed by Apple Inc., mainly using the ARM architecture. They are the basis of Mac, iPhone, iPad, Apple TV, Apple Watch, AirPods, AirTag, HomePod, and Apple Vision Pro devices.

Apple announced its plan to switch Mac computers from Intel processors to Apple silicon at WWDC 2020 on June 22, 2020.^[1][2] The first Macs built with the Apple M1 chip were unveiled on November 10, 2020. As of June 2023, the entire Mac lineup uses Apple silicon chips.

Apple fully controls the integration of Apple silicon chips with the company's hardware and software products. Johny Srouji is in charge of Apple's silicon design.^[3] Manufacturing of the chips is outsourced to semiconductor contract manufacturers such as TSMC.

A series

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 (CPU), a graphics processing unit (GPU), cache memory and other electronics necessary to provide mobile computing functions within a single physical package.^[4]

Apple A4

The Apple A4 is a PoP SoC manufactured by Samsung, the first SoC Apple designed in-house.^[5] It combines an ARM Cortex-A8 CPU – also used in Samsung's S5PC110A01 SoC^[6][7] – and a PowerVR SGX 535 graphics processor (GPU),^[8][9][10] all built on Samsung's 45-nanometer silicon chip fabrication process.^[11][12] The design emphasizes power efficiency.^[13] The A4 commercially debuted in 2010, in Apple's iPad tablet,^[8] and was later used in the iPhone 4 smartphone,^[14] the fourth-generation iPod Touch, and the 2nd-generation Apple TV.^[15]

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^[16][17] It can run at far higher clock rates than other Cortex-A8 designs yet remains fully compatible with the design provided by ARM.^[18] The A4 runs at different speeds in different products: 1 GHz in the first iPads,^[19] 800 MHz in the iPhone 4 and fourth-generation iPod Touch, and an undisclosed speed in the 2nd-generation Apple TV.

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.^[20] 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,^[21] and the 2nd-generation Apple TV^[22] have an A4 mounted with two low-power 128 MB DDR SDRAM chips (totaling 256 MB), while the iPhone 4 has two 256 MB packages for a total of 512 MB.^[23][24][25] 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.^[26]

Apple A5

The Apple A5 is an SoC manufactured by Samsung^[27] that replaced the A4. The chip commercially debuted with the release of Apple's iPad 2 tablet in March 2011,^[28] 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",^[29] according to Apple.

The A5 contains a dual-core ARM Cortex-A9 CPU^[30] 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,^[31] though it can adjust its frequency to save battery life.^[30][32] The clock speed of the unit used in the iPhone 4S is 800 MHz. Like the A4, the A5 process size is 45 nm.^[33]

An updated 32 nm version of the A5 processor was used in the 3rd-generation Apple TV, the fifth-generation iPod Touch, the iPad Mini, and the new version of iPad 2 (version iPad2,4).^[34] The chip in the Apple TV has one core locked.^[35][36] 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.^[37]

In March 2013, Apple released an updated version of the 3rd-generation Apple TV (Rev A, model A1469) 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 (it is still on a 32 nm fabrication process), this indicates that this A5 revision is of a new design.^[38] Markings tell that it is named APL7498, and in software, the chip is called S5L8947.^[39][40]

Apple A5X