MESS is a low level emulator. Dolphin is not. Low-level emulation of consoles even like the N64 is mostly infeasible at the moment. MESS works as designed, and

MESS is a low level emulator. Dolphin is not. Low-level emulation of consoles even like the N64 is mostly infeasible at the moment. MESS works as designed, and doesn't use "speed hacks" or other performance optimizations, by design.