ID devs discuss DX12, Vulcan, OpenGL

[SiDeards73]

Very interesting read, some nice comments on HDR as well

http://www.dsogaming.com/interviews...n-mega-textures-pbr-global-illumination-more/

 

[tommybhoy]

Good read thanks, learned something today.

 

[Scougar]

Really feel like they didn't answer some of the questions that well.

 

[SiDeards73]

Liked the answer to the following question

DSOGaming: While testing DOOM, we noticed some scenes in which our GPU was not used to its fullest (even though we were not CPU or VRAM limited). Is this a limitation of the OpenGL API and can we expect better GPU utilization in these scenes with Vulkan?

Axel: From data we collected with our profiling tools we do not expect the GPU to be idle for significant periods of time in a GPU limited scenario. OpenGL does not have any limitation in this regard. In general, it’s a safe assumption that it behaves similar to DirectX 11. However, we do limit the number of frames in-flight to only one, because latency is very important for a very fast paced shooter like DOOM. This could lead to slightly lower GPU usage compared to an engine that allows more frames to be buffered. We expect Vulkan to help leverage remaining free GPU time by running asynchronous compute workloads if the hardware and driver supports it.

In case this scene is limited by CPU draw calls, Vulkan will certainly help immensely. DOOM on Vulkan will also distribute the rendering to more than one thread, which will help CPUs with more than two cores. Please mind that there is still game related code like AI, path finding and physics which cannot be sped up by using a different graphics API.

(Editor In Chief: we can confirm that this scene runs way better in Vulkan.)