@mitu thanks for the reply. I turned off my shader preset to see what would happen, and it does improve performance to "mostly" 60fps. The global shader I use is just "sharp-bilinear-2x-prescale" which afaik isn't supposed to be demanding at all, so I'm surprised performance tanks so badly with it on.

Unfortunately I've screwed up the video settings for all the snes cores by attempting to remove the global shader preset from bsnes, while keeping it in place for snes9x. Shaders don't work at all for snes anymore, and different resolutions in the runcommand menu aren't even working... I don't know why that happened.

Bsnes is causing me too much trouble, so i'm just gonna uninstall it once I restore my backup...