kk the ball's in my field now
you can use powerstrip to increase the power of your graphics card
you can increase the card's chip speed or memory speed. this is overclocking. you can also do this to some CPUs if the motherboard permits it (but thats dangerous without good cooling, you could burn your chip out if you arent careful)
k, right click the task bar icon and go to performance and click Configure
slowly edge up one bar, each time clicking apply and waiting a moment to see if a major graphical messup occurs. your screen may go black/white, pictures may become strange, something will happen and you will recognize it.
save your settings frequently (hopefully not in separate files)
once a messup occurs, reboot your computer. hard reboot, as you cannot see the screen. when you log in, powerstrip will ask you if you want to load default settings to correct any problems that may have caused you to crash, choose yes.
go to your saved settings, and the bar you were slowly edging up, edge it down a bit and save and apply
if it messes up again, reboot and repeat.
do this for both bars and you may notice some great improvement in many games (though maybe not Dolphin, unless you have a really fast dual core cpu and really bad graphics card that might be holding you back)
some people have reported up to 20-30% increases in performance.
end result: you speed up the chip and memory on your video card, allowing it to handle things quicker and play faster
its totally worth buying. it turned my Radeon 9600 up quite a bit and i can handle many games well that a stock radeon 9600 would struggle with
as for CPU overclocking (this may be different in dual cores, and i repeat, some motherboards wont let you do this) you should research it a little more and find out if your board will let you do it
