nativespeed

Native speed is a term used to describe the real-time execution rate at which software is designed to run on its original hardware. In emulation and retro-gaming contexts, it refers to the speed at which the emulated system’s CPU, graphics, and audio are intended to operate so that programs behave as they did on the original console or computer. The concept is closely tied to the system’s clock rate and its frame rate, such as 60 frames per second for many NTSC-era systems or 50 frames per second for PAL-era systems.

Maintaining native speed is important for correct timing. If an emulator runs faster than native speed, timing-dependent elements like input handling, music, and game logic can become desynchronized, leading to glitches or altered gameplay. If it runs slower, input lag, slow motion, or audio stuttering can occur. Some emulators offer a frame limiter or lock to the system’s native frame rate to preserve authentic behavior, while others may allow dynamic speed adjustment to catch up or slow down as needed.

Achieving true native speed can involve different approaches. Cycle-accurate emulation aims to replicate every CPU and hardware cycle, which helps preserve timing but may require more computing power. Higher-level emulation focuses on functional equivalence and may relax timing constraints to improve performance on modern hardware. Users might balance accuracy and performance by enabling or disabling features such as frame skipping, VSync, or audio interpolation.

See also: emulation, frame rate, synchronization, vsync, cycle-accurate emulation.