nVidia GTX670 - runs my displays, does not mine
R9 290 - mines, with no displays
First and foremost, you will either need a monitor plugged into the AMD card, or you will need a dummy plug. Install the nVidia + drivers first, then install the AMD + drivers (I did not install Catalyst CC).
The only cgminer argument you need to add is:
--gpu-platform 1
After playing around with gpu-platform, gpu-map, disable-gpu, etc, I finally realized it was a simple solution and all I was missing was the AMD actually driving a display.
Hope this helps someone out there.
LTC: LMyyektyV629HbbrSR3WRu9TycnYRgiKXK