My best computer can run the accuracy core at only half speed, but that's just because it's from 2007. It can still run the balanced core at full speed, with some games faster than Snes9x, such as Dragon Ball Z: Hyper Dimension, running at 45 FPS on bsnes, and 15 FPS on Snes9x.
Using Windows Vista, or 7? If so, try disabling the DWM. With Windows 8, then yes, you ARE out of luck, because Microsoft was being stupid, and force-enabled the DWM.
Yeah, but bsnes runs all the commercially-produced SNES games perfectly (as far as we know, but each and every one has been tested), and therefore, if something runs on real hardware, it will likely run on bsnes, and vice versa.
Dude, first off, the reason for using .sfc, is because the Japanese system was called, "Super Famicom." It makes more sense. Plus, I don't know why people still recommend ZSNES, when SNES9x and bsnes are MUCH more accurate. /rant