My rig (laptop in my sig) plays Zelda WW perfectly fine indoors and out. 100% indoors and probably 85% outdoors. That game is huge, the world is massive and when outside there is a lot of info to process but it runs fine because the proper code is there for it to run that well. Now take a game like Tetris Worlds (I recently posted a game thread for the game) it only runs about half speed for me in-game, and it's just a box with some blocks falling down. The game code in Dolphin is not right for this game and so I would need a better PC to push it to full speed. It's pretty simple to understand really.
Asus Laptop: K53TA
OS: Windows 7 Home Premium, 64-Bit - SP1
CPU: AMD Llano A6-3400M, Quad-Core, 1.4GHz-2.6GHz (Overclocked)
GPU: AMD Radeon HD6650M, 1GB GDDR3 (Catalyst 13.1)
RAM: Samsung 4GB DDR3-1333
OS: Windows 7 Home Premium, 64-Bit - SP1
CPU: AMD Llano A6-3400M, Quad-Core, 1.4GHz-2.6GHz (Overclocked)
GPU: AMD Radeon HD6650M, 1GB GDDR3 (Catalyst 13.1)
RAM: Samsung 4GB DDR3-1333