Apple A8X

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, which the A8 does not, and it doesn't use the package on package configuration with included RAM which the A8 does. This is similar to how the older "X" variants, the A5X and A6X, were designed.{{Cite web |url=http://9to5mac.com/2014/10/13/ipad-components-a8x-2gb-ram/ |title=Latest iPad Air 2 component leak shows A8X chip & 2GB RAM |date=13 October 2014 |access-date=2014-10-18 |archive-date=2014-10-19 |archive-url=https://web.archive.org/web/20141019001957/http://9to5mac.com/2014/10/13/ipad-components-a8x-2gb-ram/ |url-status=live }} 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 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.{{cite web |url=http://www.anandtech.com/show/8716/apple-a8xs-gpu-gxa6850-even-better-than-i-thought |title=A8X's GPU - Even Better Than I Thought |publisher=Anandtech |date=November 11, 2014 |access-date=September 3, 2015 |archive-date=November 30, 2014 |archive-url=https://web.archive.org/web/20141130014356/http://www.anandtech.com/show/8716/apple-a8xs-gpu-gxa6850-even-better-than-i-thought |url-status=live }}

The A8X has video codec encoding support for H.264. It has decoding support for H.264, MPEG‑4, and Motion JPEG.{{Cite web |title=iPad Air 2 - Technical Specification |url=https://support.apple.com/kb/SP708?locale=en_US |access-date=2022-11-05 |website=support.apple.com}}

The A8X's branch predictor has been claimed to infringe on a 1998 patent.{{cite web |url=https://www.theregister.co.uk/2014/02/04/cupertino_copied_processor_pipelining_claims_wisconsin_u/ |title=Cupertino copied processor pipelining claims Wisconsin U |last1=Chirgwin |first1=Richard |date=February 4, 2014 |website=www.theregister.co.uk |publisher=The Register |access-date=February 3, 2014 |archive-date=February 4, 2014 |archive-url=https://web.archive.org/web/20140204072902/http://www.theregister.co.uk/2014/02/04/cupertino_copied_processor_pipelining_claims_wisconsin_u/ |url-status=live }}{{cite news|url=https://arstechnica.com/tech-policy/2015/10/apple-faces-862m-patent-damage-claim-from-university-of-wisconsin/|title=Apple faces $862M patent damage claim from University of Wisconsin|author=Joe Mullin|date=October 14, 2015|access-date=October 14, 2015|publisher=Ars Technica|archive-date=April 20, 2017|archive-url=https://web.archive.org/web/20170420045722/https://arstechnica.com/tech-policy/2015/10/apple-faces-862m-patent-damage-claim-from-university-of-wisconsin/|url-status=live}} On October 14, 2015, a district judge found Apple guilty of infringing U.S. patent {{patent|US|5781752}}, "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 (WARF), a firm affiliated with the University of Wisconsin. 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, that argued that Apple did not infringe on the patent owned by the Wisconsin Alumni Research Foundation.{{Cite news |url=https://www.reuters.com/article/ip-patent-apple/apple-urges-appeals-court-to-toss-506-million-patent-loss-to-warf-idUSL2N1N12RW |title=Apple urges appeals court to toss $506 million patent loss to WARF |last=Wolfe |first=Jan |publisher=Reuters |date=October 26, 2017 |access-date=February 22, 2018 |archive-date=February 23, 2018 |archive-url=https://web.archive.org/web/20180223050957/https://www.reuters.com/article/ip-patent-apple/apple-urges-appeals-court-to-toss-506-million-patent-loss-to-warf-idUSL2N1N12RW |url-status=live }} On September 28, 2018, the ruling was overturned on appeal and the award thrown out by the U.S. Federal Circuit Court of Appeals.{{cite news |url=https://www.reuters.com/article/us-apple-decision-patent/apple-wins-reversal-in-university-of-wisconsin-patent-lawsuit-idUSKCN1M81TV |title=Apple wins reversal in University of Wisconsin patent lawsuit |last=Stempel |first=Jonathan |publisher=Reuters |date=September 28, 2018 |access-date=November 17, 2018 |archive-date=November 17, 2018 |archive-url=https://web.archive.org/web/20181117105059/https://www.reuters.com/article/us-apple-decision-patent/apple-wins-reversal-in-university-of-wisconsin-patent-lawsuit-idUSKCN1M81TV |url-status=live }} The patent expired in December 2016.{{cite news |url=https://www.reuters.com/article/us-ip-apple-patent-idUSKBN1AB023 |title=Apple ordered to pay $506 million to university in patent dispute |last=Wolfe |first=Jan |publisher=Reuters |date=July 25, 2017 |access-date=July 26, 2017 |archive-date=July 26, 2017 |archive-url=https://web.archive.org/web/20170726015547/https://www.reuters.com/article/us-ip-apple-patent-idUSKBN1AB023 |url-status=live }}

• iPad Air 2
• iPad Pro (J98 & J99, unreleased)

• Apple silicon, the range of ARM-based processors designed by Apple.
• Comparison of ARMv8-A cores

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Category:Computer-related introductions in 2014

Category:Apple silicon

Category:Products and services discontinued in 2017