N64 worked great until yesterday...

[ssshake]

I know, this is the worst kind of forum post. "I changed something yesterday and now things are bad, what's wrong?"

Raspberry Pi 3
2.5amp power supply
Heat sinks
Fan
No over clock settings
Trying to play mario 64
Frame rate / sound is immediately choppy on title screen and in game.

This was smooth before. I've had the system over clocked to 1350 and running stock and under both conditions the game played fine.

Now, the game is basically unplayable. I dont remember changing anything of significance. Other than editing the two n64 config files to change button mappings for a controller. However the game played fine when testing after that change.

I did also update retropie from a recently installed image. I can't promise that I verified the game performance after that update. I think it was fine though.

I'm low on disk space, but not starved.

Filesystem Size Used Avail Use% Mounted on
/dev/root 30G 28G 631M 98% /

I've tried different emulators. Rice, glide, etc. They all behave poorly.

I had the system over clocked as mentioned, with heat sinks and a fan. This seemed fine for a while. I reverted the over clock as part of troubleshooting since the game also played fine at regular clock speed.

I have two pi's and I've tested that same SD card on both. It plays poorly on both.

I cloned the sd card and loaded it up on a different one, same results.

I uninstalled/reinstalled the two n64 packages under main.

I'm expecting that this is a software/config issue but I have no idea what to check.

I suppose my question is, if you were in this situation where would you start?

I'm assuming if I loaded an earlier backup image and tested with that things would be fine. Maybe I should start by testing that assumption, but if that turns out to be fine, what next?