@mitu I think it's from the limited specs of the Pi Zero. I was actually really surprised that both CD based systems even worked on a Pi Zero in the first place. Somebody told me that they tried CHD files for both emulators on a Pi Zero and the Sega CD didn't perform well. Essentially a CHD File is a modified 7zip archive, so I'm not really surprised. I will eventually test it myself and update this thread when I know.