I would first try the latest revision of Dolphin and see if that helps any. Then I'd use the 64bit build if possible.
Lastly, you'll probably need to overclock to 2.4Ghz at least and to do that you'll need a good cooler (not the stock one).
Lastly, you'll probably need to overclock to 2.4Ghz at least and to do that you'll need a good cooler (not the stock one).