Author Topic: Ways to speedup pixel shader execution  (Read 1713 times)

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Ways to speedup pixel shader execution
« on: February 20, 2020, 06:07:57 PM »
A rendering engine’s performance should be viewed holistically, in a top-down fashion using tools like Nsight and PIX or whatever your target platform supports, to identify where the performance bottleneck is before focusing on a specific area like the pixel shader cost. The GPU is a pipeline with various fixed and programmable units and each can have different impact on performance based on the content we push to it, eg number and size of triangles, implemented graphics technique complexity (lighting model, SSAO, SSR quality), rendertarget and texture resolution. Having said that, a large chunk of GPU time in a frame is spent on pixel shaders so in all likelihood you’ll spend a lot of time optimising them.

As in most optimisations efforts, the performance of a pixel shader can be improved in two ways: by not running it at all if possible and, if not, by making it cheaper to run.