   Fullscreen triangle
  Hi,recently I remembered something about using 1 triangle for fullscreen post-processing passes instead of 2 (quad). The idea was to save a few pixel-operations. I'm having a hard time to find any more detailed info on this though. I guess the challenge lies in finding the proper texture coordinates.Has anyone tried it? Does it even make a noticeable difference performance-wise?   
  Haven't tried it, but getting the texture coordinates should be easy if you just calculate them from screen coordinates.   ;  indeed, it's simple, lets assume your vertices for the rect areV00   V10V01   V11you need to calculate just T verticesV00   V10   TV10V01   V11TV01so that's simplyTV10 = V00+(V10-V00)*2;TV01 = V00+(V01-V00)*2;The speedup you get depends on the pixel-block-granularity your GPU works with, cause two triangles share (at least) one block per block-line (on the shared edge). But 'cause they're individually rasterized, that shared block is spawned twice to the fragment units. rasterizing one triangle has no such overhead, you share one block per block line.to calculate your speedup, simply doMaxTime = (BlockSize-PixelWidth)/PixelWidth;MinTime = (BlockSize-2xPixelWidth)/PixelWidth;SpeedUp = 1/Time;e.g. some Radeon have 16x16 blocksize, and let's say you render 1280x720p, worst case speedup should be: = (1280-16)/1280; = 0.9875 = 1.0127 = 101.27%;  Thanks Krypt0n!   ;  My question was answered but I'm wondering where I can find some info about "pixel blocks" ect. One source I found, talked about GPUs always processing 2x2 pixels because of derivatives, so they probably mean something else.   ;  I remember the radeon x1k series was the first one with dynamic branching from ATI and they had quite some marketing paper about their tiny and efficient block size, some reviews copied those papers:http://www.rage3d.com/reviews/video/atix1800xt/index.php?p=5but usually it's not easy to find public information about the size of blocks, but you can check their gpgpu paper for the minimal amount of threads they have to group. The funky marketing names for those blocks from amd/ati is "wavefront" and for nvidia it's "warp".   ;  Thanks for the link, I'll have a look.Sounds like the benefit from the fullscreen triangle is bigger with older GPUs, though. I implemented it now, because it was really easy as you pointed out, but  can't say it gives much of an performance boost in my case. On the other hand its so simple, that there's no reason not to do it.   ;  I am sure I have read this advice using a single tri for more modern GPUs.Related to "Tiles", maybe look this up rather than blocks?