I’m new, so this question is probably pure ignorance on my part, but how do I know which download, RetroArchCG.dmg or RetroArch.dmg, to install?
RetroArchCG.dmg has support for Cg shaders baked in. I believe you’ll need to install Nvidia’s Cg Toolkit framework from their site or else it will crash. RetroArch.dmg doesn’t support Cg shaders at all, and you won’t need the framework, but you’ll have to use the GLSL shaders instead, which is usually fine.