I have a few settings for advmame which I have found to make it more smooth. I use a Beelink GT-King Pro but it might work ok for less powerful chips:
Edit your /storage/.advance/advmame.rc file in SSH and edit it, and add:
sound_latency 0.032
sound_normalize yes
sound_samplerate 44100
sync_resample internal
display_rgbeffect none
display_vsync yes
display_resizeeffect none
sync_fps 60
Make sure there are no dupliate config records in the file, save and close.