I am trying to use three 24" 1920x1200 monitors with an ASUS GTX590 graphics card installed on an ASUS P9X79 Deluxe motherboard. I have them connected to the three DVI connectors on the back of the card. When I boot Windows 7 and use the Monitors Control Panel, I can get the full 1920x1200 resolution on two of the monitors. However, the third monitor always shows up as dark. I have swapped monitors/connectors to no avail (one of the monitors is always dark, according to connection). Each monitor works fine when connected singly. I have also reduced resolutions thinking that there may be a memory problem, also to no avail. I have not tried any changes in the UEFI/BIOS settings. I would greatly appreciate any help in overcoming this problem.