Sorry, yet another dGPU question! Can anyone confirm that either running Windows via Bootcamp, or connecting an external display will force use of the dGPU in the mid/high-level rMBP 15? I nearly always use an external monitor, except when travelling, so I don't want to find myself generating unnecessary heat when I don't actually need the dGPU (such as writing documents). I'm also concerned about running Bootcamp on battery power. If Windows always uses the dGPU (which I understand it does), then I would expect battery life to be much worse in Bootcamp than in Mac OS X. Is this true? Thanks, John.