SNES gameplay slowdown, framerate and audio stay at 100%.

[rsimmy]

Pi Model: RPi3
Power Supply used: Vilros
RetroPie Version Used: 4.1
Built From: latest image
USB Devices connected: Logitech wireless keyboard dongle
Controller used: 8bitdo NES30 Pro
Emulator: lr-snes9x 2010
SD card: Samsung EVO Select 32gb class 10

I'm currently doing a 100% Yoshi's Island playthrough on a Pi 3, and I've noticed during some graphically intense parts, the game will slow waaay down. The odd part is framerate stays the same, and the audio stays smooth as butter. Some audio effects will just cut out completely, but the level music is fine during the slowdown, no stutter or anything.

I know some SNES and NES games have slowdowns on the original cart (Mega Man games for example) but this isn't the case for Yoshi's Island.

I'm wondering what the best emulator to use would be. I've tried all the main ones (snes9x 02, 05, 10) and the optional lr-snes9x package with no year at the end.

I've overclocked arm to 1.4ghz and core to 550mhz, but saw no improvement so I went back to stock.

There have been 4+ sections that cause this slowdown.

Edit: after some further research, it seems it's the Super FX emulation causing the slowdown, which may be why it's not affecting framerate it music.

Should I overclock the Super FX in the RetroArch menu? I've messed with it before and it froze.

[Rion]

@rsimmy yes Overclocking the Super-FX should solve your problems. Have a savestate ready when the slowdowns start and try diffrent overclock settings to get the best results.

[rsimmy]

@Rion
That did the trick! I feel kinda silly. It froze the first time I messed with it, so I didn't think to try it again. Bumping it up to 40 or 60hz, saving the game override, and resetting completely fixed a super slow laggy part.

I'm curious to know how this works.