Here is another back-dated community service type of post — I just discovered that Adobe’s Lightroom 3 doesn’t force my Macbook Pro (Core i7 processor and discreet NVIDIA graphics card) into using the NVIDIA chip while editing photos. Instead, the computer just utilizes the integrated Intel graphics, which is fairly weak in comparison to the NVIDIA GeForce GT 330M. Basically what this means for Lightroom performance is that as I page through photos in lightroom, the images don’t render as fast (I am using 1:1 previews too, but it can take a second for them to snap into focus and have the correct sharpness with the lightroom edits). The NVIDIA chip renders the preview files way faster as I’m editing. You can force the switch by intstalling this little app by Cody Krieger: http://codykrieger.com/gfxCardStatus/ – it lets you manually switch graphics cards. When I’m plugged in, I use the NVIDIA chip while editing photos; when I’m unplugged,  make a decision based on how far away from an outlet I am because the NVIDIA chip uses way more power. Hope this is helpful to other photographers out there in cyberspace!