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One of the biggest expected announcements at SIGGRAPH this week has been delayed: The Kronos Group has yet to release its Vulkan API. Fortunately, Imagination Technologies has taken over, and has released a tech demo to make the months of waiting more bearable. Gnome Horde demonstrates the impressive performance advantages that this low-level API provides compared with other graphics APIs.

The video below shows a consumer tablet outfitted with a GPU PowerVR G6430. The right half reproduces this scene using OpenGL ES, and the left half uses Vulkan.

The large number of objects to render stresses the hardware, and this is especially noticeable when the camera zooms out. At that point, OpenGL collapses, with CPU utilization above 90% and frame rates in the single digits. The greater control granted by Vulkan allows the scene to optimize its programming so the CPU load is shared between all cores and the frame rate never falls below 30 fps.

This performance increase is not free, as the post of Imagination says it comes at the expense of more work by the programmer: “All of the features require implementation in code, so the use of Vulkan does come with added code complexity compared to OpenGL ES. However, Imagination is committed to continuing full support for OpenGL ES for a long time to come alongside developing a new Vulkan API driver for PowerVR Rogue GPUs. Devices with the new Vulkan API should bring new optimization opportunities and increased efficiency to application developers.”

This also means that OpenGL will not disappear, and developers will be free to choose to program their projects at a high-level using OpenGL, or choose Vulkan to further optimize their code — although you can safely assume all the main game engines will add support for Vulkan.

It seems clear that the new API will allow the arrival of hitherto unthinkable games to mobile devices and budget graphics. There are other low-level APIs that come with the same promises: Microsoft DirectX 12 and Apple’s Metal. The advantage of Vulkan is that as a free API it will be available on any platform that wishes to adopt it. Google has recently confirmed Vulkan support in the new versions of Android, and other platforms that will also support Vulkan include Windows and Linux, especially Steam OS (Vulkan seems to be Valve’s secret weapon).

We don’t have definitive dates for the release of Vulkan, or for its integration with Android, but Kronos is still planning to release it later this year.

Read more http://www.extremetech.com/gaming/212025-imagination-pits-vulkan-api-against-opengl-in-gnomes-per-second-test