Instructions
Close down any programs in the background that can take up memory and resources. For the best speed and performance on a low-end computer, the SNES emulator should be the only program running.
Enable the "MMX" settings in the options menu of the emulator provided both your computer and the emulator support this feature. This will noticeably increase the speed of the emulator. If your SNES emulator does not have the option to enable "MMX," try one of the alternatives available on emulator sites such as Zophar or the Emulator Zone.
Lower the resolution of the SNES emulator. You can do this from the video options menu of the emulator. Experiment by gradually decreasing the resolution until you find a setting where you are happy with the speed and the quality. Run the emulator in full-screen mode instead of a window mode to get more speed.
Enable the "Auto Frame Skip" option if the emulator supports it. This option allows the emulator to get more speed by not displaying every frame. If your computer is too slow, it will skip a lot of frames while speeding up the emulator, resulting in choppy frame rates.
Disable the "Vsync" option in the emulator to prevent the frame rate from syncing to your monitor's refresh rate. With "Vsync" enabled, the visuals might be smoother but the emulator will be a lot slower.
Disable the sound in the options menu of your SNES emulator. Doing so greatly increases your speed but you will have no audio, so use this option as a last resort.