Array of samplers vs. texture array

Chris_F · 2014-03-23T03:00:04

I'm curious as to what the tradeoffs would be for using an array of samplers with the bindless texture extension over using texture arrays. It seems like there would likely be more overhead with sampler arrays. On the other hand, with texture arrays you are limited to 2048 slices on a lot of modern GPUs. You could potentially have a lot more than that with bindless, and each texture can have it's own dimensions and sampler properties.

Graphics and GPU Programming Programming

Started by Chris_F March 19, 2014 05:26 AM

9 comments, last by Chris_F 10 years, 1 month ago

Chris_F

3,030

Author

March 23, 2014 03:00 AM

I'm quite sure that the cost will go up if you were to have divergence within a single warp. Try randomizing your index based on the pixel coordinate and see how it fares.

Just tried rendering a full screen quad that uses a hash of the screen coordinates to pick a random number to index an array of 262,144 sampler handles to 1x1 textures. Was only getting 8 fps. Would liked to have tried and even larger array, but I was getting GL_INVALID_OPERATION at 521,728 textures. With 256 textures I get 22 fps. My understanding is that Kepler supports this while AMD's GCN flat out does not.