I just hooked up my second monitor today it it won't show up. My computer detects there is one but there is no picture on the other one. I currently have it hooked up using a Dvi-d(single link) cable although the ports are Dvi-d(dual link), I don't know if it matters though. I have also tried a regular VGA cable with it and I have the same problem. (I am using only 1 video card) Mostly so I can game on the main screen and browse on the second.
SAPPHIRE 100366-2L Radeon R7 260X 2GB 128-Bit GDDR5
PCI Express 3.0 CrossFireX Support Video Card
Mother board Ports(DVI-D and VGA): http://i.imgur.com/ND9AyqU.jpg
Graphics card Ports(DVI-D and HDMI): http://i.imgur.com/ha3pw1L.jpg