Something is wrong with the FPS of SSBM..

[DurpeyBrao]

When I got it for the first time, oddly enough Dolphin was running at 80-100 FPS on Super Smash Bros. Melee, even if I set the limit to 60FPS.
Now, for some reason, the FPS is decreasing rapidly during midgame. Is there any way to stop this from happening?

Just to clear this out, this all happened on the same computer, with the same CPU, graphics card, and everything. Nothing has changed between the issues shown. Even if so, the previous computer I had was worse than the one I now have. MUCH worse.

I'm thinking it might be a certain thing that I clicked in the options when I was trying to keep a decent FPS. AKA I pretty much maximized performance. Still, the game's sound and FPS is very choppy.

[Kurausukun]

Create a file in your Dolphin.exe directory called "portable.txt" (you don't have to do anything else to it). This makes a "User" folder in your Dolphin directory instead of using the global user directory, so it'll reset all of your settings to their defaults. Right away, you can check "Skip EFB Access from CPU," but don't change anything besides that and see how the game runs then. After that, keep enabling the settings you want until you find whatever it is that's messing things up.

Alternatively, it could be your subpar CPU, though Melee is a pretty light game.