My 12 core 3.46ghz 5,1 Mac Pro with 48gb of ram is still a beast for CPU rendering. However, with its GTX 680, Fusion 360 viewport navigation performance is much worse than my iMac & MacBook Pro (GTX 780M & Radeon Pro 460). All 3 are 4gb graphics cards. EDIT: GTX 680 is a 2GB card. Heck, even the new 13" MBP has better viewport performance with its integrated graphics.. Only on the Mac Pro do the edge lines disappear during view movement and take a second to reappear once movement stops. Unchecking "limit effects during navigation to maintain framerate" leads to an unusable framerate. The latest nvidia web driver for the card makes no difference. I wouldn't consider 3D CAD view movement to be super GPU intensive so any insight here would be much appreciated. Do I need to upgrade the graphics card?