SNES definitely draws on-the-fly. If it has any sort of *buffer, byuu's right: it's for sprites only.
Reasoning? Why would Nintendo add a framebuffer to the SNES, when the NES didn't have one? The hardware *is* directly related. Also, thwe SUperscope is a heavy argument against a framebuffer.
It's been calculated which way sprites are handled, and the basic answer is "there's no way to tell". The data necessary to hold the tiles and x position info are roughly equal to the demands of plotting the sprites out as tiles are fetched, and only handling priority and palette lookup during rendering to screen.
anomie's research always said that p-hi-res was simply double-pumping the DAC, and there was no reason to think modes 5 and 6 were different.
