Hi, I have a 2011 macbook pro 15 with the upgraded graphics card. I'm connecting it to an HP external 30" monitor with a mini display port to Dual link DVI adapter. I'm getting pretty disappointing performance when it's hooked up the external display. Often when dragging windows around, it gets really choppy, like I'm using a really slow graphics card with a a poor refresh rate. Performance seems even worse with Windows 7. Not sure what to do to fix the problem, but its a big issue for me since I was planning on using this computer mostly as a desktop replacement, and running Windows 7 and Solidworks (CAD) a good bit. Beginning to regret selling my 2006 mac pro which this is replacing Any suggestions would certainly be appreciated. Thanks!