Modern GPUs have to put the vertices in vram before they can render them. That means immediate mode emulation is effectively this everyframe: a) cop

Modern GPUs have to put the vertices in vram before they can render them. That means immediate mode emulation is effectively this everyframe: a) copy all vertices from user code to some cpu buffer b) at draw time, copy cpu buffer to vram c) ask GPU to draw steps A and B are very expensive CPU wise as well as waste memory. vs OpenGL ES 2.0 init time: put vertices in vram everyframe: ask GPU to draw