The Apple A8X is a

64-bit In computer architecture, 64-bit Integer (computer science), integers, memory addresses, or other Data (computing), data units are those that are 64 bits wide. Also, 64-bit central processing unit, CPUs and arithmetic logic unit, ALUs are those ...

ARM-based

system on a chip A system on a chip or system-on-chip (SoC ; pl. ''SoCs'' ) is an integrated circuit that integrates most or all components of a computer or other electronic system. These components almost always include a central processing unit (CPU), memory ...

(SoC) designed by

Apple Inc. Apple Inc. is an American multinational technology company headquartered in Cupertino, California, United States. Apple is the largest technology company by revenue (totaling in 2021) and, as of June 2022, is the world's biggest company b ...

and manufactured by

TSMC Taiwan Semiconductor Manufacturing Company Limited (TSMC; also called Taiwan Semiconductor) is a Taiwanese multinational corporation, multinational semiconductor contract manufacturing and design company. It is the world's most valuable semicon ...

. It first appeared in the

iPad Air 2 The iPad Air 2 is the second-generation iPad Air tablet computer designed, developed, and marketed by Apple Inc. It was announced on October 16, 2014, alongside the iPad Mini 3, both of which were released on October 22, 2014. The iPad Air 2 i ...

and only is used in the iPad Air 2, which was announced on October 16, 2014. It is a variant of the A8 inside the iPhone 6 family of

smartphones A smartphone is a portable computer device that combines mobile telephone and computing functions into one unit. They are distinguished from feature phones by their stronger hardware capabilities and extensive mobile operating systems, which ...

and Apple states that it has 40% more CPU performance and 2.5 times the graphics performance of its predecessor, the

Apple A7 The Apple A7 is a 64-bit system on a chip (SoC) designed by Apple Inc. It first appeared in the iPhone 5S, which was announced on September 10, 2013, and the iPad Air and iPad Mini 2, which were both announced on October 22, 2013. Apple states ...

. The latest software update for the iPad Air 2 using this chip was iPadOS 15.7.1, released on October 27th 2022 as it was discontinued with the release of

iPadOS 16 iPadOS 16 is the fourth and current major release of the iPadOS operating system developed by Apple for its iPad line of tablet computers. The successor to iPadOS 15, it was announced at the company's Worldwide Developers Conference (WWDC) on ...

in 2022 due to hardware limitations of the A8X.

Design

The A8X has three cores clocked at 1.5 GHz, a more powerful GPU compared to the A8 and it contains 3 billion transistors. With an extra 100 MHz and an additional core, the A8X performs around 13% better on single threaded and 55% better on multithreaded operations than the A8 inside the iPhone 6 and iPhone 6 Plus. Further comparison to the A8 shows that the A8X uses a metal

heat spreader A heat spreader transfers energy as heat from a hotter source to a colder heat sink or heat exchanger. There are two thermodynamic types, passive and active. The most common sort of passive heat spreader is a plate or block of material having hi ...

, which the A8 does not, and it doesn't use the

package on package Package on a package (PoP) is an integrated circuit packaging method to vertically combine discrete logic and memory ball grid array (BGA) packages. Two or more packages are installed atop each other, i.e. stacked, with a standard interface to rout ...

configuration with included

RAM Ram, ram, or RAM may refer to: Animals * A male sheep * Ram cichlid, a freshwater tropical fish People * Ram (given name) * Ram (surname) * Ram (director) (Ramsubramaniam), an Indian Tamil film director * RAM (musician) (born 1974), Dutch * Ra ...

which the A8 does. This is similar to how the older ''"X"'' variants, the A5X and

A6X The Apple A6X is a 32-bit system-on-a-chip (SoC) designed by Apple Inc., introduced at the launch of the 4th generation iPad on October 23, 2012. It is a high-performance variant of the Apple A6 and the last 32-bit chip Apple used on an iOS de ...

, were designed. Instead the A8X in the iPad Air 2 uses an external 2 GB RAM module. In a first for Apple, the A8X is reported to have a semi-custom GPU. The A8X uses an 8-cluster GPU based on

Imagination Technologies Imagination Technologies Limited is a British semiconductor and software design company owned by Canyon Bridge Capital Partners, a private equity fund based in Beijing that is ultimately owned by the Chinese government. With its global headquar ...

PowerVR Series 6XT architecture. Officially, the largest implementation of Rogue is a 6-cluster design, indicating that Apple has made customizations to the design in order to provide higher performance. This GPU is referred to as the GXA6850, with the "A" denoting the Apple customization. The A8X has video codec encoding support for

H.264 Advanced Video Coding (AVC), also referred to as H.264 or MPEG-4 Part 10, is a video compression standard based on block-oriented, motion-compensated coding. It is by far the most commonly used format for the recording, compression, and distri ...

. It has decoding support for H.264, MPEG‑4, and

Motion JPEG Motion JPEG (M-JPEG or MJPEG) is a video compression format in which each video frame or interlaced field of a digital video sequence is compressed separately as a JPEG image. Originally developed for multimedia PC applications, Motion JPE ...

Patent litigation

The A8X's

branch predictor In computer architecture, a branch predictor is a digital circuit that tries to guess which way a branch (e.g., an if–then–else structure) will go before this is known definitively. The purpose of the branch predictor is to improve the flow ...

has been claimed to infringe on a 1998 patent. On October 14, 2015, a district judge found Apple guilty of infringing U.S. patent , "Table based data speculation circuit for parallel processing computer", on the Apple A7 and A8 processors. The patent is owned by

Wisconsin Alumni Research Foundation The Wisconsin Alumni Research Foundation is the independent nonprofit technology transfer organization serving the University of Wisconsin–Madison and Morgridge Institute for Research. It provides significant research support, granting tens ...

(WARF), a firm affiliated with the

University of Wisconsin A university () is an institution of higher (or tertiary) education and research which awards academic degrees in several academic disciplines. Universities typically offer both undergraduate and postgraduate programs. In the United States, t ...

. On July 24, 2017, Apple was ordered to pay WARF $506 million for patent infringement. Apple filed an appellate brief on October 26, 2017 with the

U.S. Court of Appeals for the Federal Circuit The United States Court of Appeals for the Federal Circuit (in case citations, Fed. Cir. or C.A.F.C.) is a United States court of appeals that has special appellate jurisdiction over certain types of specialized cases in the U.S. federal court ...

, that argued that Apple did not infringe on the patent owned by the Wisconsin Alumni Research Foundation. On September 28, 2018, the ruling was overturned on appeal and the award thrown out by the U.S. Federal Circuit Court of Appeals. The patent expired in December 2016.

Products that include the Apple A8X

References

{{Application ARM-based chips Computer-related introductions in 2014 Apple silicon Products and services discontinued in 2022

Design

Patent litigation

Products that include the Apple A8X

See also

References