use second video card
 

Is there a way to use the second video card in my linux system? I have 2 nvidia cards, one is onboard, and this is the one regnum detects and uses, and I would rather use the pci-express card.

Try disabling the built in one in BIOS.

Or the X11R6 configuration.... Regnum doesn't detect anything to run AFAIK, it just starts up OpenGL and goes. Whatever you see as detected graphics is the first OpenGL renderer string you get from glxinfo.

Even changing the order of initialisation should fix that.