I found this post: Latest snes9x-SDL sources?
He has the same problem as me with Mipsel and the newest Snes9x version.
Because of the performance problems of the current Snes9x, i ported 1.51 to SDL and Dingux too. It uses a different APU implementation. Now it renders the sound in good quality. But the FPS are always still too slow. About 6-7fps.
The configuration has a deep influence of how fast the emulation runs. I tired several different combinations...but always too slow.
Now i'm going to port every version from 1.40->1.5x to see what the reason for the speed problems.
I also found the Zaurus Port of Snes9x 1.39 which was used to port it to Dingux.
Maybe i find a hint, when comparing this with Dingux port and original Snes9x 1.39.