For those interested, the most recent builds of dolphin are running some gamecube games flawlessly. They have made some serious progress the last couple of months. I have only tested 3, but Double Dash, Luigis Mansion, and Animal Crossing are all running at 100%. No noticeable frame drop at all. These are the only settings I changed:
CPU Settings > Emulated CPU Clock Speed =
60% (you can try 40% as well)
Video Settings > Video Backend =
OpenGL
> Enhancements > Internal Resolution =
2x Native
That was it! I left everything else on it's default. Double Dash never dropped below 55 frames. Sound and everything worked perfectly. If you guys have issues, or want me to try to test something, let me know. The exact Dolphin Build I used was 5.0-3318. You can download that build
here, or you can see all the builds here:
https://dolphin-emu.org/download/list/master/1/