Gamecube/wii Emulator has very low FPS

Hey, guys

I recently downloaded Dolphin: a GameCube and Wii Emulator. I tried to play the Super Smash Brothers Melee, but the framerate was really low. Not like other games i’ve ever played before. I’ve got an ATI Radeon Saphire HD 4600 AGP. Its GPU runs at 400 MHz and it has 1024 MB of graphic memory. Still it cant get the framerate of Super Smash Borthers Melee above 3 or 4 FPS. Does anybody know how to fix this or is my pc just unable to play GameCube games???