OK, with an AMD card that has a display port, you must use the display port for all 3 monitors to work. Also you will need a monitor that has a displayport for this to work. Use display port for monitor 1, a DVI port for monitor 2 and 3. If you use the HDMI port it will knock out one of the DVI ports. Generally speaking the DVI port closest to the display port is DVI port 1 (which you will loose when using an HDMI cable) and then DVI port 2. Once this is all setup correctly, then use with in the CCC panel to set up all three monitors. Check out AMD's site for videos on how to setup and run multimonitors.
Link Removed - Invalid URL