The combination ATi+nvidia is not working at all and i also don't recomand ATI for 3D apps.
The combination Quadro + GeFroce works only 50%. If the Quadro drivers detects non Quadro cards the pro features will be disabled. For example Quadro 2000and GTX 560 Ti 2 GB or GTX 580 3 GB. If Quadro 2000 detect the GTX card, it starts act like a GTS 450. No pro features will be enabled like: the image quality in viewport inside solidworks or other CAD software, no Quadro acceleration and stability, no 30 bit support for 30 bit monitor via display port, the pro options from nvidia control panel are totally gone... so on and so forth.
You must put the Quadro on the first slot and the GTX card on the second slot. The monitors will be plugged in the Quadro. I don't recommend connecting the monitor in the GTX. In the OS you'll need to install the Quadro drivers only, no GeForce driver at all. When you are working in CAD you must disable from Device Manager the GTX card so the Quadro card is unable to detect it. After you done your job with modeling/animation you can close the CAD software, activate back the GTX and do your rendering in octane
. This is the only way. The dual boot is not working. To install a second OS and install only the GeForce driver is not possible because the system recognize the first card as the default, the first card that is installed on the first slot.