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openglmultisampling

Will performance drop down by using multisampled OpenGL context with multisampling off?

Create a multisampled OpenGL context, turn off multisampling by glDisable, compare to using non-multisampled context, how performance are affected?

Solution

  • MSAA ( or FSAA) level definitely affects the performance.Just make a basic OpenGL app with several primitives (preferably of big size so that fragment shader would have to do a lot of work),and you will notice performance drop.Of course it depends on you hardware specs but yes ,there is a noticeable impact after all.Why does that happen?Because the pixels are sampled multiple times which means more work for fragment shader.Read this for a thorough explanation .