It’s still a quire choppy fps wise. Also the sound still get crackles due to buffer underruns. Try over clocking your pi and that should increase performance. Also run in console rather that x windows.
Mario 64 is about the only game I’ve had any luck running so far. I run at arm_freq=1000 and sdram_freq=500 and it plays quite smoothly, including sound. No luck with other games though.
Maybe make sure your power supply is enough? I am using this one, which came recommended by other pi users.
I think RetroPie pulls the master branch from the repository. The ric_dev branch is usually slightly faster but more likely to have errors.
To get the best performance you should do the following:
1. Overclock the Pi to its maximum stable speed (use ‘sudo raspi-config’ )
2. Run mupen64plus using sudo/root so that it can change its scheduler policy to ‘hog’ the CPU
3. Use 128Mb GPU/CPU memory split. The current code doesn’t force the kernel to keep pages in ram so if the split is too high, then pages will be swapped and slow emulation down. (Fix coming soon)
4. Run mupen64plus without the desktop (use Ctrl+Alt+F1; [log in]; sudo telinit 2)
5. The video-gles2n64 plugin is the fastest so use it if it works with the ROM you want to play.
6. Modify mupen64plus.cfg as detailed in other posts and in the repo wiki (Although it needs more detail)