I'm running an ATI gpu in my project build that I plan to use for 3D (blender) and some gaming. I know that I can run an nvidia card on the ATI mobo thats installed, but would the performance be so much better that I should buy another card? (I'm under the impression that there are better Linux drivers for the nvidia cards). Also, I'm seeing trails whenever I move a window and this is with compiz off. Could this be a symptom of a bad driver? Any thoughts???