Venjix

Personally I just renamed the "MAME" folders to "Arcade" and it recognized it right away. Probably the easiest way to fix on your end too?

There really isn't a proper answer for your question, as there are too many factors to consider in the builds (such as what emulators you're using, the size of your library, and any regular PC games/applications you're running alongside it). If there's a specific feature or functionality that you're having problems running, it'd be easier to be more specific so that it could be narrowed down to code, option settings, or bottlenecks on your system.