https://www.youtube.com/watch?v=t_rzYnXEQlE
FIXING the ENTIRE SM64 Source Code (INSANE N64 performance)
by: Kaze Emanuar

He made Super Mario 64 run at 3 times higher fps even on original hardware. He did it by making sure cpu unit and graphical unit fight for memory less, and adding memory alignment and such. Because of that, the game now requires an expansion pack, increasing the memory requirements from original 4 MB to 8 MB. Plus a lot of other work.

Pity, why they fuck with hardware that isn't even produced anywhere anymore.