@laephis I had a issue were my tv would only use pal 50hz even when I ran a usa nes rom .... Hence I had stuttering and slowdown try a pal game see if that runs fine if so that's your issue. I had to change the .config to force my tv to find 60hz maybe this is the same issue.

^^^^^ issue solved I speak through my hoop

@Locke141 I've just read the NES wiki and I can't see where it says that nestopia is the default.

I see "lr-nestopia is preferred due to better accuracy and the ability to play Famicom Disk System games, plus better input latency. lr-fceumm is slightly faster, which may give a benefit to Raspberry Pi 1/0 users"