Metal (API)

Summary

Metal is a low-level, low-overhead hardware-accelerated 3D graphic and compute shader API created by Apple, debuting in iOS 8. Metal combines functions similar to OpenGL and OpenCL in one API. It is intended to improve performance by offering low-level access to the GPU hardware for apps on iOS, iPadOS, macOS, and tvOS. It can be compared to low-level APIs on other platforms such as Vulkan and DirectX 12.

Metal
Developer(s)Apple Inc.
Initial releaseJune 2014; 9 years ago (2014-06)
Stable release
24 / October 2022; 1 year ago (2022-10)
Written inShading language: C++14, Runtime/API: Objective-C
Operating systemiOS, iPadOS, macOS, tvOS
Type3D graphics and compute API
LicenseProprietary
Websitedeveloper.apple.com/metal/

Metal is an object-oriented API that can be invoked using the Swift, Objective-C or C++17[2] programming languages. Full-blown GPU execution is controlled via the Metal Shading Language. According to Apple promotional materials: "MSL [Metal Shading Language] is a single, unified language that allows tighter integration between the graphics and compute programs. Since MSL is C++-based, you will find it familiar and easy to use."[3]

Features edit

Metal aims to provide low-overhead access to the GPU. Commands are encoded beforehand and then submitted to the GPU for asynchronous execution. The application controls when to wait for the execution to complete thus allowing application developers to increase throughput by encoding other commands while commands are executed on the GPU or save power by explicitly waiting for GPU execution to complete. Additionally, command encoding is CPU independent thus applications can encode commands to each CPU thread independently. Lastly, render states are pre-computed beforehand, allowing the GPU driver to know in advance how to configure and optimize the render pipeline before command execution.[4]

Metal improves the capabilities of GPGPU programming by using compute shaders. Metal uses a specific shading language based on C++14, implemented using Clang and LLVM.[5]

Metal allows application developers to create Metal resources such as buffers, textures. Resources can be allocated on the CPU, GPU, or both and provides facilities to update and synchronize allocated resources. Metal can also enforce a resource's state during a command encoder's lifetime.[6] [7]

On macOS, Metal can provide application developers the discretion to specify which GPU to execute. Application developers can choose between the low-power integrated GPU of the CPU, the discrete GPU (on certain MacBooks and Macs) or an external GPU connected through Thunderbolt. Application developers also have the preference on how GPU commands are executed on which GPUs and provides suggestion on which GPU a certain command is most efficient to execute (commands to render a scene can be executed by the discrete GPU while post-processing and display can be handled by the integrated GPU).[8]

Metal Performance Shaders edit

Metal Performance Shaders is a highly optimized library of graphics functions that can help application developers achieve great performance at the same time decrease work on maintaining GPU family specific functions.[9] It provides functions including:

  • Image filtering algorithms
  • Neural network processing
  • Advanced math operations
  • Ray tracing

History edit

Metal has been available since June 2, 2014 on iOS devices powered by Apple A7 or later,[10] and since June 8, 2015 on Macs (2012 models or later) running OS X El Capitan.[11]

On June 5, 2017, at WWDC, Apple announced the second version of Metal, to be supported by macOS High Sierra, iOS 11 and tvOS 11. Metal 2 is not a separate API from Metal and is supported by the same hardware. Metal 2 enables more efficient profiling and debugging in Xcode, accelerated machine learning, lower CPU workload, support for virtual reality on macOS, and specificities of the Apple A11 GPU, in particular.[12]

At the 2020 WWDC, Apple announced the migration of the Mac to Apple silicon. Macs using Apple silicon will feature Apple GPUs with a feature set combining what was previously available on macOS and iOS, and will be able to take advantage of features tailored to the tile based deferred rendering (TBDR) architecture of Apple GPUs.[13]

At the 2022 WWDC, Apple announced the third version of Metal (Metal 3), which would debut with the release of macOS Ventura, iOS 16 and iPadOS 16. Metal 3 introduces the MetalFX upscaling framework, which renders complex scenes in less time per frame with high-performance upscaling and anti-aliasing.[14] Also announced possibility to use C/C++ for Metal API.[15]

Supported GPUs edit

The first version of Metal supports the following hardware and software:[16]

The second version of Metal supports the following hardware and software:

The third version of Metal supports the following hardware and software:

Adoption edit

According to Apple, more than 148,000 applications use Metal directly, and 1.7 million use it through high-level frameworks, as of June 2017.[17] macOS games using Metal for rendering are listed below.

Title Developer (macOS version) Game engine MacOS release date (OpenGL) Metal-based release date Metal support notes
EVE Online CCP Games N/A 14 October 2021
Civilization VI Aspyr Media LORE 24 October 2016 Metal support since 5 April 2019[citation needed]
Batman: Arkham City Feral Interactive Unreal Engine 3 18 October 2013 Metal support since 21 February 2019 with v1.2[citation needed]
Dota 2 Valve Source 2 18 July 2013 MoltenVK was announced on 26 February 2018.[18] The option to use this became available on 31 May 2018.[19]
Quake II id Software Quake II engine 9 February 2019 A port using MoltenVK was released as vkQuake2.[20]
Tomb Raider Feral Interactive Foundation Engine 17 January 2014 Metal support with v1.2 in July 2019[citation needed]
Rise of the Tomb Raider Feral Interactive Foundation Engine 12 April 2018
Shadow of the Tomb Raider Feral Interactive Foundation Engine 2019
F1 2016 Feral Interactive EGO Engine 4.0 6 April 2017
Life Is Strange 2 Feral Interactive Unreal Engine 4 2019
Life Is Strange: Before the Storm Feral Interactive Unity Engine 13 September 2018
Divinity: Original Sin II Larian Studios Divinity Engine 2 31 January 2019
Baldur's Gate III Larian Studios Divinity Engine 4.0 22 September 2023 Metal support in early access since 6 October 2020[citation needed]
Company of Heroes 2 Feral Interactive Essence Engine 3 21 January 2015 Metal support since 19 October 2018[citation needed]
Hitman Feral Interactive Glacier 2 20 June 2017
Sid Meier's Railroads! Feral Interactive Gamebryo 1 November 2012 Metal support since 18 December 2018[citation needed]
Warhammer 40,000: Dawn of War III Feral Interactive Essence Engine 4 9 June 2017
Total War: Rome Remastered Feral Interactive TW Engine 2 29 April 2021
Total War: Three Kingdoms Feral Interactive TW Engine 3 23 May 2019
Total War: Warhammer Feral Interactive TW Engine 3 19 April 2017
Total War: Warhammer II Feral Interactive TW Engine 3 20 November 2018
Total War Saga: Thrones of Britannia Feral Interactive TW Engine 3 24 May 2018
Total War Saga: Troy Feral Interactive TW Engine 3 13 August 2020
Medieval II: Total War Feral Interactive TW Engine 2 17 December 2015 Metal support since 25 October 2018[citation needed]
Empire: Total War Feral Interactive TW Engine 3 4 March 2009 Metal support since 16 December 2019[citation needed]
Napoleon: Total War Feral Interactive TW Engine 3 2 July 2013 Metal support since 25 October 2019 with v1.2[citation needed]
Total War: Shogun 2 Feral Interactive TW Engine 3 31 July 2014 Metal support since 4 October 2019[citation needed]
Total War: Shogun 2: Fall of the Samurai Feral Interactive TW Engine 3 18 December 2014 Metal support since 4 October 2019[citation needed]
Bioshock Remastered Feral Interactive Unreal Engine 2.5 22 August 2017
Bioshock 2 Remastered Feral Interactive Unreal Engine 2.5 22 October 2020
F1 2017 Feral Interactive EGO Engine 4.0 25 August 2017
Deus Ex: Mankind Divided Feral Interactive Dawn Engine 12 December 2017
DiRT Rally Feral Interactive EGO Engine 2.5 16 November 2017
Ballistic Overkill Aquiris Game Studio Unity Engine 5 28 March 2017
BattleTech Harebrained Schemes Unity Engine 5 24 April 2018
Mafia III Aspyr Media Illusion Engine 11 May 2017
World of Warcraft Blizzard Entertainment WoW Engine 23 November 2004 Metal support since August 2016[citation needed]
Starcraft Blizzard Entertainment Modified Warcraft II engine 20 November 2001 Metal support since 2 July 2020 with v1.23.5[citation needed]
StarCraft II Blizzard Entertainment SC2 Engine 27 July 2010 Metal support in beta since 24 January 2017[citation needed]
Heroes of the Storm Blizzard Entertainment SC2 Engine 2 June 2015 Metal support in beta since 24 January 2017 (temporarily removed on 29 November 2017[21] until ?)[citation needed]
Fortnite Epic Games Unreal Engine 4 25 July 2017
Obduction Cyan Worlds Unreal Engine 4 29 March 2017
Everspace Rockfish Unreal Engine 4 26 May 2017
Ark: Survival Evolved Studio Wildcard Unreal Engine 4 29 August 2017
Observer Bloober Team Unreal Engine 4 24 October 2017
Unreal Tournament Epic Games Unreal Engine 4   Cancelled Metal support since January 2017[citation needed]
Refunct Dominique Grieshofer Unreal Engine 4 5 September 2016
Cities: Skylines Paradox Interactive Unity Engine 5 10 March 2015 Metal support since 18 May 2017[citation needed]
Universe Sandbox Giant Army Unity Engine 5 TBA Metal support in beta since June 2017[citation needed]
War Thunder Gaijin Entertainment Dagor Engine 4 1 November 2012 Metal support added 24 May 2017 (removed in ? 2018 and reintroduced 27 August 2020)[citation needed]
The Witness Thekla, Inc Thekla Engine 8 March 2017
Micro Machines World Series Virtual Programming Unity Engine 5 30 June 2017
Guardians of the Galaxy: The Telltale Series Telltale Games Telltale Tool 18 April 2017
Batman: The Enemy Within Telltale Games Telltale Tool 8 August 2017
Minecraft: Story Mode - Season Two Telltale Games Telltale Tool 11 July 2017
ARMA 3 Virtual Programming Real Virtuality TBA Metal support in beta since 17 September 2017[citation needed]
MXGP3 Virtual Programming Unreal Engine 4 23 November 2018
Gravel Virtual Programming Unreal Engine 4 20 January 2019
X-Plane 11 Laminar Research N/A 30 May 2017 Metal support in beta since 2 April 2020[22]
Headlander Double Fine Productions Buddha Engine 18 November 2016
The Sims 4 Maxis SmartSim 17 February 2015 Metal support added 12 November 2019[citation needed]
The Elder Scrolls Online Zenimax Online Studios N/A 4 April 2014 22 October 2018 OpenGL Renderer replaced with Vulkan via MoltenVK wrapper (translates Vulkan API calls to Metal) in patch 4.2.5
Sky: Children of the Light Thatgamecompany N/A 18 July 2019 Native Metal support added since pre-global live in November 2017
Resident Evil Village Capcom RE Engine 28 October 2022 First macOS game with MetalFX support

See also edit

References edit

  1. ^ McWhertor, Michael (September 9, 2014). "This is the game Apple used to show off iPhone 6". Polygon. Vox Media. Archived from the original on September 11, 2014. Retrieved September 9, 2014.
  2. ^ "Getting started with Metal-CPP - Metal".
  3. ^ Apple Inc. "Metal Shading Language Specification" (PDF).
  4. ^ "Setting Up a Command Structure". Apple Inc.
  5. ^ "Metal Shading Language Guide". September 8, 2014. Retrieved September 10, 2014.
  6. ^ Apple Inc. "Setting Resource Storage Mode".
  7. ^ "Synchronizing a Managed Resource". Apple Inc.
  8. ^ "GPU Selection in macOS". Apple Inc.
  9. ^ "Metal Performance Shaders".
  10. ^ Machkovech, Same (June 2, 2014). "Apple gets heavy with gaming, announces Metal development platform". Ars Technica. Condé Nast.
  11. ^ Smith, Colin; Meza, Starlayne (June 8, 2015). "Apple Announces OS X El Capitan with Refined Experience & Improved Performance". Newsroom. San Francisco: Apple.
  12. ^ "Archived copy of the Metal homepage, November 2017". Apple Developer. Apple. November 20, 2017. Archived from the original on November 20, 2017 – via Wayback Machine.{{cite web}}: CS1 maint: bot: original URL status unknown (link)
  13. ^ "Bring your Metal app to Apple Silicon Macs". developer.apple.com. Retrieved July 13, 2020.
  14. ^ "Discover Metal 3". developer.apple.com. Retrieved June 24, 2022.
  15. ^ "Program Metal in C++ with metal-cpp". developer.apple.com. Retrieved September 10, 2022.
  16. ^ Chiappetta, Marco (December 11, 2018). "Apple Turns Its Back On Customers And NVIDIA With macOS Mojave". Forbes.
  17. ^ Apple Inc. "WWDC 2017 Platforms State of the Union".
  18. ^ "Vulkan Applications Enabled on Apple Platforms". Khronos Group Press Release. Retrieved February 24, 2021.
  19. ^ Larabel, Michael (June 1, 2018). "Initial Vulkan Performance On macOS With Dota 2 Is Looking Very Good". Phoronix. Retrieved June 5, 2018.
  20. ^ Kondrak, Krzysztof [@k_kondrak] (February 9, 2019). "vkQuake2 gets MacOS support" (Tweet). Retrieved February 9, 2019 – via Twitter.
  21. ^ "HEROES OF THE STORM BALANCE PATCH NOTES — NOVEMBER 29, 2017". news.blizzard.com. November 29, 2017.
  22. ^ "X-Plane 11.50 Public Beta 1: Vulkan and Metal Are Here". X-Plane Developer. April 2, 2020. Retrieved April 2, 2020.

External links edit

  • Metal for Developers
  • Metal Programming Guide (preliminary)
  • WWDC14 demo; extended version
  • Install macOS 10.14 Mojave on Mac Pro (Mid 2010) and Mac Pro (Mid 2012) - Apple article explaining what GPUs are compatible with Apple's Metal APIs on Mac OS 10.14 (Mojave) operating system