The Gamecube was more efficient than it was powerful. Nintendo did a really good job engineering it to be a nice machine that could put out nice results for its time. It didn't have the brute force power of the Xbox or even the PS2 in many cases, but more than made up for it with its ease of programming and well balanced design. It's basically the same hardware in the Wii, just at a lower speed and less memory. There's plenty of threads in the history of this forum you can peruse through to get an idea of how capable the system was for its time. As swaaye pointed out you should go ahead and do a search and have a wealth of information to go through.