0 Replies Latest reply on Apr 25, 2014 11:23 AM by Taz1024

    GL 4.4.12874 Texture array clear performance

    Taz1024

      Hi,

       

      I ran into an unexpected performance issue with clearing 2d texture arrays, so I tried some work-arounds. The huge differences in gpu time seem to indicate there's something wrong with the implementation of clears (clearbuffer, cleartexsubimage) for 2d arrays. Here are the results:

       

      rgba16f, 64x64x192:

      - glClearBufferfv(): 400us

      - glClearTexSubImage: 400us

      - Draw 192 slices: 136us

      - Compute: 35us

       

      depth24s8, 64x64x192:

      - glClearBufferfi(): 334us

      - glClearSubTexImage(): 334us

      - Draw 192 slices: 27us

      - Compute: no image store avail for depth-stencil =(

       

      Also worth noting is that clearbuffer and clearsubteximage take about ~40us cpu setup time compared to compute setup of ~15us.

       

      cheers,

      -mh