So in order to display an image on 600*800 size screen,
there is a 1.4M buffer in demand in traditional architecture.
But in index architecture, how much buffer is determined by the scene.
If the scene consists of 130 thousands of triangles,
there is a 1.4M buffer in demand in index architecture.
But in embedded system the scene is simple,
so it is said that the index architecture is used to saves storage spaces.