What is the path of the MAME.CFG file that you edited? I will try that. I have only edited the RETROARCH.CFG, so maybe i am editing the wrong one. I don’t think it is related to overclocking, and the NES/SNES emulators work fine, so I don’t think it is an issue with the processing power of the Pi itself. I will dig around a bit and report back if i have anything useful to add. Thanks for your reply!

dave