Film grain is a process that is used to hide imperfections in games. For example, a graphical error can be covered with a slight blur. In addition, film grain gives the game a cinematic effect. It adds a visual tingle as if what you are seeing is through a virtual television.  The film grain hides many graphical flaws such as jaggies from anti-aliasing and gives a more fantastic visual spectacle. However, it doesn't make the image look smooth or clean. To improve performance, turn OFF AA on the console.