I know that the Map-Reduce model is a common model of parallel computation, perhaps some sort of standard way(?). I also know that graphic cards are specifically built for parallel computation. However when reading about the graphic pipeline I am not sure if there is a point at which the Map Reduce model is used. If not, what kind of parallel computations (just the general model of them so I could read more about it) are done during the typical rendering process of modern graphics cards? If it is used, where would that be on the below pipeline?