I purchased 5 monitors and one video card to run them on the same computer. My motherboard has only one pci express x16 and that's where the external graphic card goes onto. The graphic card support 4 monitors with minidisplay ports. I have the converters for mini display ports to dvi.
And then the 5th. monitor which is my main monitor is going to use the motherboard's internal video card. Do you think it can be done? I'm a stock trader so that's the reason why I need this setup.
If your CPU and motherboard supports flexible Display Interface you can use all 5 monitors using internal and external graphics if you have that many ports of course.
Just enable this in bios and you are good to go.