Super Mario 64 – 1996 Developer Interviews
>The N64 hardware has something called a Z-Buffer, and thanks to that, we were able to design the terrain and visuals however we wanted.This was a huge advantage for them. In contrast, for Crash Bandicoot -- which came out for the PS1 at the same time -- we had to use over an hour of pre-computation distributed across a dozen SGI workstations for each level to get a high poly count on hardware lacking a Z-buffer.A Z-buffer is critical, because sorting polygons is O(n^2), not O(n lg n). This is because cyclic overlap breaks the transitive property required for an N lg N sorting algorithm.The PS2 got Sony to parity; at that point both Nintendo and Sony had shipped hardware with Z-buffers.