Hello All I have 3 X 28 Inch Samsung monitors. They are all working fine. I just installed a 2nd video card in my Mac Pro 5,1 so I could run a third display. First card: ATI Radeon HD 5770 1 GB 1) has 2 DVI Inputs, 1 HDMI input and 1 Display port Input Second Card (newer) 2) 2 X Mini Displayports 1) DVI Port I have had all my monitors hooked up and working but I wanted to run them all off Display ports. I can't seem to get the all 3 monitors to work at the same time with just display port connections though. Monitor 1 works fine Display port to display port But when I hook up the 2nd and third monitor with display port to mini DisplayPort cords only 1 will show. The card doesn't seem to be able to show both monitors at the same time. When i check displays in System Pref. It shows 3 monitors but does one display is always black. Any ideas?