Thanks Paul, I intend to use this for 2D purpose. Later I am going to replace these monitors with AOC D2367PH (They are good for stereoscopic 3D, Viewsonic supports stereoscopic 3D only with Tridef (Tridef does not support openGL)). so for my configuration can I use 2 MiniDP to VGA active converters and 2 MiniDP to HDMI passive converter. But as I stated earlier I tried using MiniDP to HDMI passive converter it is not working even for single display. I tried connecting single monitor with this converter and started my system, the window boot up screen appears in the monitor and after starting windows it disappears then only MiniDP to VGA is able to provide display.