[ubuntu] Switchable Graphics? Using which GPU?

view story

http://ubuntuforums.org – I just installed 12.10 onto my laptop that has a 7670m and an intel 4000. Additional Sources tab in Software Sources says I'm using x.org drivers for my 7670m card. I was wondering if switchable graphics was enabled and if there was anyway to tell which gpu was being utilized? I keep hearing my fans upspin when I do things like open chrome. Thanks! (Hardware)