I have an Asus P9x79 Deluxe, for my system at home. The main use of my computer is Davinci Resolve, which needs a graphics card for the GPU and another one for the GUI. For the GUI I have a Quadro 600, for the GPU I have a GTX 680.
For some reason, not when I first built the system, but after a few months, the system is not running Resolve as well as it should. What I did, after a lot of back and forth with the guys at Resolve, was to take out the Quadro 600, which actually allowed the program to run faster! So I'm thinking that somehow the board isn't communicating the right info, but at this point it is beyond me technically, actually beyond most people, so I don't know where to turn to for a solution.