@DjLeChuck
Ok but I never got clear sound on any game with snes9x-next emulator is that normal ?

I tried Pocketsnes emulator instead of snes9x-next and it seams to fix a lot of problem.
Is there a drawback to using pocketsnes ?

I have a Pi3 with recalbox 4.0 installed.
I tried a couple of games and I have concern.

I tried Super Punch Out witch yes is playable but as frequent slow down almost 80% of the time. The music crackle always and never at the right speed.

Is this a normal behaviour with a Pi3 (not overclocked but with heatpad) for snes emulation.

I tried the same game on my computer and snes9x and it was flawless.

My Pi3 is connected only with HDMI and I tried putting rom on the SD and on a USB stick. I use a ps3 controller connected with USB.
Is there something Im doing wrong?

I tough by buying Pi3 I would get the same result that I get with my computer for SNES. Every forum talks about N64 performance but my problem is with snes.

For the record I also tried Retropie with the same result.