I have spent the last week or so playing with Vulkan, “the next generation OpenGL initiative”. Vulkan is very new; the Vulkan 1.0 specification was released on February 16, 2016. It has a number of advantages over OpenGL; for example, it is a lower level API, similar to Direct3D in its use. It’s features include:
- Reduced driver and CPU overhead;
- CPU scaling to multiple core CPUs. OpenGL was originally designed for single CPUs, and scaling is difficult and poorly implemented;
- Shaders may still be GLSL-based, but the shaders are precompiled, rather than compiled in the program. In future, other shader languages and compilers should become available; and,
- The Vulkan SDK is available for hardware from mobile devices up through high-end graphics cards.
For more information on Vulkan, see:
- The Wikipedia entry for Vulkan (API)
- A Brief Overview of Vulkan API
- The Vulkan Graphics API Is Here—and Your NVIDIA GPU Is Ready (well not my nVidia GPU)
Sounds great, but there are cons:
- You have more control, but more control means you will be writing more C code than you would for OpenGL;
- Graphics driver support is spotty. For example, at the time I write this, nVidia and AMD support some of their graphics cards, but not all. nVidia’s Windows driver version 356.45 is the only version that supports Vulkan, but their most current Windows driver is at least 361.60. Intel has no Windows drivers that implement Vulkan, and only beta drivers for Linux.
- There are not a lot of sample programs available yet, and of course, no books. There does seem to be a number of Java examples.
Here are a couple of beginner guides:
Update – May 20, 2016
Intel has released a Windows 10 beta driver with Vulkan support, but this driver only supports Vulkan on their 6th generation Intel Core processors with HD Graphics 510, 515, 520, 530, Intel® Iris™ Graphics 540, Intel® Iris™ Graphics 550, and Intel® Iris™ Pro Graphics 580. Since I do not have a computer with any of these processors, I am still out of luck.
nVidia has also updated their Windows graphics drivers to now support the Geforce 800M series. My computer has a Geforce 840M GPU, so I am now able to use the Vulkan libraries. I performed a quick test and the test suite that I created before this original Vulkan post now compile, link and execute without error.
I will begin using Vulkan to build graphics programs once my series of posts on Chaotic Systems and Fractals are completed.
Great, I had some fun. So what did I learn from my playing?
- The current version of the Vulkan specification is 1.0.5, the C++ wrapper supports version 1.0.4, and the only available SDK is version 188.8.131.52. There is a mismatch here.
- Intel support for Vulkan is pretty much non-existent. My computer has an integrated Intel GPU.
- nVidia does not currently support Vulkan for their 800 series GPUs, and there is considerable question as to whether they ever will. Of course, my computer also has an nVidia 840M GPU.
- Using the Vulkan API, I was able to query the GPU for information about its capabilities; unfortunately, I cannot acquire a surface for drawing on for my nVidia GPU.
So I am stuck at this point. I do have a few options:
- Wait and hope that nVidia comes to its senses and supports the 800 series GPUs.
- Upgrade my nVidia graphics card to an nVidia card that supports Vulkan; or maybe upgrade to an AMD graphics card.
- Wait for Intel to publish Windows drivers for their graphics cards. My laptop computer also has an integrated Intel GPU so this is a potential option.
- Go back to OpenGL and concentrate on shaders, since knowledge of shaders and the shader language are transferable to Vulkan.
I think I will choose options 1, 3, and maybe 4.