Nvidia Optimus State Viewer Download

Using this tool you could be sure about whether the optimus technology is actually working and you may not have to force anything since its for the best. But if you really need the dedicated card to be grinding all the time then you can force it through the nvidia control panel as others have said.

Nvidia Optimus State Viewer Download

All you have to do is run the tool and then when you think the load is heavy, like in the middle of a huge battle ingame, you alt-tab out of the game and you can clearly see the state of optimus in the tool.