I already posted earlier that I experienced issues with D700 (on 8 core nMP): slow viewport at very high polygon count. I kept searching as I was not happy at all, especially when I found out that iMac's (GTX 780M) viewport performance was way better at high poly count in some 3D applications than the D700 BUT there is hope! Here is what I found, great test videos using Maya http://arstechnica.com/apple/2014/01/two-steps-forward-a-review-of-the-2013-mac-pro/4/ the D700 seems to be actually great but currently it performs WAY better under Windows Under Windows-bootcamp, at 36million polygon, Maya is still silky smooth, and still greatly usable at 72million. While the same scene under OSX-Maya cannot be used at 36million... So I think Apple's driver sucks a lot at this point, need URGENT polishing. If you are a new MacPro owner, please help to get this sorted by sending them feedback, send them this review link etc. The more people do it, the more they will take it seriously. Just google up "Apple Feedback" It makes me upset, as I thought the "FirePro" and the price they charged means PRO drivers. On the other hand it is good that it is not hardware issue, and it is lucky that you can use bootcamp but that's not why you buy a Mac.