multi gpu rendering.

[monstercameron]

which is it? how does it work?
is it:

1. rendering the frames in an alternating pattern based on the symmetry of the setup?
2. rendering portions of the display on separate gpus?
3. rendering the different layers in differed shading techniques on separate gpus?
4. rendering the main image on a gpu then applying the post processing on the others?

 

[BFG10K]

It's primarily 1 although I believe 2 is still around for rare cases.

The way you describe 3 is sort of like the multi-GPU AA modes, and I don't think 4 has ever existed in consumer space.