I recently downloaded Fatal Fury Special and Real Bout Fatal Fury 2, and they both play absurdly fast. I tried the suggested Nvidia fix by turning on Vsync for the main executable files for both games, but no dice. I have windows 11. Anyone have any suggestions?

Just take the ROM and use it in an other emulator, like MAME or Kawaks.

https://www.winkawaks.org/

https://www.mamedev.org/

For Fatal Fury Special, the ROMs are fatfursp.zip and neogeo.zip, located in GOG Games/Fatal Fury Special/Game.

Thanks for the advice, but I can't seem to get it to work in Mame. I put the game and bios zips in the rom folder, but when I select the game in the menu, it says I'm missing several neogeo bios files. I've tried other bios files, with no luck, and none of the tutorials I've seen has told me to do anything different. I'm just using the game and bios zips (didn't rename or unzip them) from GOG, so I don't see why they wouldn't have the necessary files. What am I doing wrong here?

You could try to alt-tab out of the game, press Strg+Shift+ESC or right-click on the Windows logo to open taskmanager, right-click on the process, click on Go to details ... right-click on the app, click on Set Affinity and select 1 or 2 cores (CPU 1 or CPU 1 and 2).

If this doesn't help, try and set the app's Priority to Below Normal or Low

If this also fails, follow this guide to manually change the [i]Maximum processor frequency[/url] This will slow the whole system down, so don't set the value too low, and don't forget to reset the setting when you quit the game!

Lastly you could try and buy slowdown apps, like Mo'Slo or CPUKiller 3, or look for free giveaways of those or similar tools. They also make it possible to artificially slow down your system, so this and other old games can run at a playable speed.