if you connect a keyboard and hit the x key as the rom is loading, you can select the default emulator for neogeo games, but isn’t pifba faster the gngeo? i use it for all my neo geo games and they run top speed (although i did turn the screensmoothing/videosmoothing option off in the config file)
i heard gngeo doesn’t use the pi’s GPU, so is slower. pifba does.