Thank u for your response, i heard some graphics cards have 1 VGA , 1 DVI and 1 HDMI ports. As u told (DVI-VGA) if i convert HDMI-VGA, results total 3 VGA i think. is it possible? in that case of 'working together' i actually meant that i need to display different things through these three ports. Eg:- if i sets a virtual class room, i need one display to the admin, one to the teacher and the 3rd one to projector for students at the same time.