Furnace achieves the authentic sound of videogame hardware by emulating sound chips as accurately as possible, using **emulator cores**. in some cases there are multiple cores to choose from, each with different strengths and weaknesses. here are the major differences between them all.
- **ymfm**: default playback core. much less CPU usage than Nuked-OPM, but less accurate. recommended for users with mobile, last-gen or earlier hardware.
- **Nuked-OPM**: default render core. much more accurate than ymfm, due to the emulator being based on an image of the die map taken from a real YM2151. very CPU heavy, only recommended for users with recent hardware.
- **YMF276-LLE**: a new core written by the author of the Nuked cores, specifically focused on YMF276 emulation. it is very slow and not useful for real-time playback. Produces audio comparable to output of Sega Mega Drive model 2 and later Fujitsu FM Towns computers, doesn't emulate DAC distortion of the original YM2612.
- **Nuked-PSG Mod**: more accurate, but not by that much. this originally started as an emulator for the YM7101 PSG sound generator, but was modified to emulate the SN7 as the MAME core was deemed unsatisfactory by some.
- **YM2608-LLE**: a new core written by the author of the Nuked cores. high accuracy, but _extremely_ high CPU usage, far beyond any other emulation core. (over 500% CPU time on 10th gen Intel Core i5!)