For Gamecube emulation to be viable, follow these simple steps. Invent a time machine, travel 4 years into the future, and bring back a decent PC back as well as a developed emulator that has yet to exist. Then you all set!
And you expect to get any decent speed off of a 1.5GHz PC? D:
There is no PC capable of fully emulating a Gamecube, namely because you need a PC much more powerful then the Console to emulate. As well, there are Gamecube emulators but none are well enough developed to emulate much very well.