Which is faster: glBlitFramebuffer a renderbuffer or render a fullscreen texture?

OpenGL
1

which is faster and more efficient?

  1. rendering on a fullscreen quad;
  2. Using a renderbuffer and rendering using glBlitFramebuffer.
2

There is no generic answer for this (for all blits configs, for all GPUs, for all drivers, for all host systems, etc.), of course.

Try it on your system with your GPU, your GPU driver, your application, your specific framebuffer formats/sizes/sample counts/etc., and see.

Also, keep in mind that your perception of how fast/slow a method is going depend on, not just the raw speed of the specific framebuffer transfer you requested, but also the internal synchronization the driver has to do to wait for prior operations to complete before it can even start the blit/quad render.

2 Likes