I have an asus k53ta-bbr6 with a 6520g and a dedicated 6650m the system is supposed to be crossfired during high graphic applications but from the proformance i have seen it is not doing this. i do have enable dual graphics selected in my catalyst menu.
Are you sure that laptop will do what you think it will and not just swap over to the faster video card automatically when it does something that needs it? I don't think it will use both cards, but will pick one or the other depending on the graphic load.
+1^ not a good idea to overclock a laptop, unless it's made with beefy heat management in mind, it's designed for a pretty narrow heat range. Which is why so many laptop tend to cook themselves, aside from people clogging up the fan ducts with pillows and dust when it's in use.