Is there a way to view and control the powerstate of the discrete GPU on a 2011 MBP in OSX? I noticed that running with the discrete GPU uses more power and generates more heat. I just need the discrete GPU to drive an external monitor, I'm not concerned about performance.

By controling the power state I expect to control the voltage and frequency of the GPU. This could be achieved by either changing the power state of the GPU or the voltage and frequency directly.

I just want to make sure that the MBP runs as cool as possible.
I use gfxCardStatus to see and control if my discrete GPU is in use. Is that what you want?

To see how much power is consumed you can use iStat Menu for example...