Vulkan (API)

Vulkan

Original author(s)	Khronos Group with contributions from AMD[1][2][3][4][5]
Developer(s)	Khronos Group
Initial release	Early 2016 (2016) (expected)[6]
Development status	Active
Operating system	Cross-platform
Platform	Cross-platform
Type	3D graphics and compute API[7]
Website	khronos.org/Vulkan
As of	18 December 2015

Vulkan, initially referred to as "glNext", is a low-overhead, cross-platform 3D graphics and compute API first announced at GDC 2015 by the Khronos Group.^[7][8][6] The Vulkan API was initially referred to as the "next generation OpenGL initiative" by Khronos, but use of those names were discontinued once the Vulkan name was announced.^[9]

Like OpenGL, Vulkan targets high-performance realtime 3D graphics applications such as games and interactive media across all platforms, and offers higher performance and lower CPU usage, much like Direct3D 12 and Mantle. In addition to its lower CPU usage, Vulkan is also able to better distribute work amongst multiple CPU cores.^[10] Vulkan is derived from and built upon components of AMD's Mantle API, which was donated by AMD to Khronos with the intent of giving Khronos a foundation on which to begin developing a low-level API that they could standardize across the industry, much like OpenGL.^{[3][7][11][12][13][14][15]}

Availability

According to Khronos, the Vulkan specification is complete and has been submitted for legal review and is awaiting release in early 2016; the targeted release date at the end of 2015 was not met. The Vulkan SDKs for Android, Linux and Windows are still under development.^[16]

Features

Vulkan is intended to provide a variety of advantages over other APIs as well as its spiritual predecessor, OpenGL. Vulkan offers lower overhead, more direct control over the GPU, and lower CPU usage.^[6] Intended advantages include:

• Reduced driver overhead, reducing CPU workloads.^[17]
• Reduced the load on CPUs through the use of batching, leaving the CPU free to do additional computation or rendering than otherwise.^[18]
• Intelligent and even CPU scaling for multi-core CPUs, which are by far the majority type of CPU on the market. Previous APIs like DirectX 11 and OpenGL 4 were initially designed for use with single-core CPUs and could not easily use multiple or scale workloads evenly across multiple, leaving some CPU cores underworked and some not even utilized at all, resulting in performance issues and frequent CPU bottlenecks.^[19]
• OpenGL uses the high-level language GLSL for writing shaders which forces each OpenGL driver to implement its own compiler for GLSL that executes at application runtime to translate the program's shaders into executable code for the target platform. Vulkan will instead provide an intermediate binary format called SPIR-V (Standard Portable Intermediate Representation), analogous to the binary format that HLSL shaders are compiled into in DirectX. This reduces the onus on driver vendors, allows shader pre-compilation, and permits application developers to write shaders in languages other than GLSL.^[20]
• Cross-platform API supported on both mobile devices and high-end graphics cards.
• OS agnostic to improve the portability of applications created using the API.

History

The Khronos Group began a project to create a next generation graphics API in July 2014 with a kickoff meeting at Valve Corporation.^[21] At SIGGRAPH 2014 the project was publicly announced with a call for participants.^[7]

According to the US Patent and Trademark Office, the trademark for Vulkan was filed on February 19, 2015.^[22]

Vulkan was formally named and announced at Game Developers Conference 2015, although speculation and rumors centered around a new API existed beforehand and referred to it as 'glNext'.^[23]

On March 3, 2015, Valve announced the Source 2 engine, a game engine to support the Vulkan graphics API.^[24][25]

In early 2015, LunarG (funded by Valve) developed and showcased a Linux driver for Intel which enabled Vulkan compatibility on the HD 4000 series integrated graphics, despite the open source Mesa drivers not being fully compatible with OpenGL 4.0 until later that year.^[26][27] There is still the possibility^[28] of Sandy Bridge support since it supports compute through Direct3D11.

On August 10, 2015, Google announced that future versions of Android would support Vulkan.^[29]

On December 18, 2015, the Khronos Group announced that the 1.0 version of the Vulkan specification was nearly complete, and would be released when conformant drivers were available.^[6]

Compatibility

Initial specifications state that Vulkan will work on hardware that currently supports OpenGL ES 3.1 or OpenGL 4.X and up.^[30] As Vulkan support will require new graphics drivers, this does not necessarily imply that every existing device that supports OpenGL ES 3.1 or OpenGL 4.X will have Vulkan drivers available.

See also

• OpenGL – Another graphics API by the Khronos Group
• Mantle – A low-level graphics and compute API from AMD, the foundation of Vulkan
• Direct3D – Windows-only graphics API. Version 12 is a low-level API similar to Vulkan
• Metal – A low-level graphics and compute API for iOS and OS X
• Glide – An early low-level graphics API limited to rasterization

References