FPS drops to what feels like 30fps seemingly randomly

[Legislacerator]

I only play Mega Man X, but when I'm playing the FPS will drop to what seems like <30 but the Snes9x still displays the game running at 60fps. I am 100% confident this is not in-game slowdown. The game will run at the same speed but the framerate will feel horrible. I truly can't figure out why/when this happens it feels completely random and it makes it almost impossible to enjoy. My CPU usage only sits at about 10% the entire time.

[odditude]

MMX definitely bogs down at times on real hardware - why are you sure it's not that?

[Legislacerator]

MMX definitely bogs down at times on real hardware - why are you sure it's not that?

I speedrun the game. I've beaten it over 100 times, a majority of which were on original hardware. Found out that switching my monitor from 144hz to 60hz and enabling Vsync fixed the lag issues, but vsync added horrible input lag.

[odditude]

that's a good reason!

if your monitor supports 59Hz modes, i've found that snes9x will do a marvelous job of running steadily without needing vsync. i generally run windowed, though - fullscreen sometimes adds a frame of lag on my setup (win10, geforce 9-series, HDTV via HDMI).