I have a ATI HD4600 graphics card with two display outputs installed in my system. Now I want to connect a third screen to my PC and thought about using the onboard graphics controller. Unfortunately the product guide of my Intel DG965WH motherboard states that "Either the integrated GMA X3000 graphics controller is used or a PCI Express x16 add-in card can be used. When a PCI Express x16 add-in card is installed, the GMA X3000 graphics controller is disabled."
Is there any way around that, so I can use the onbard video and my ATI card? If there's not - just out of curiosity - what's the reason that I can only use either of the two?