Discreet AND Integrated Graphics card?

I have a Lenovo G505s, and it has both a discreet and a integrated graphics card. The discreet is AMD Radeon HD 8650G which should be pretty good or at least decent with modern gaming. However, I feel as though any game I play: Battlefield, Diablo 3, common flash games; they do not have enough FPS even though I lower the graphics settings.

Is there a way to know if my discreet graphics card is doing most of the work? Because it seems like it's not. Or is there a way to turn off the integrated graphics card? So far the device manager says the CPU and the integrated card are one in the same.

Added (1). I also have Dual channel 8Gb of ram, so that's not a problem.

Get latest amd chipset drivers and graphics drivers

and there would be options to choose which would be the graphics processor

download the chipset and graghics driver here:

http://support.lenovo.com/...D=DS035837

and check gameplay videos in youtube heres one