I have a PC (Dell Optiplex 740) with a ATI HD 4300/4500 in it. It has 1 x DVI, 1 x VGA and 1 x HDMI outputs on it. I run windows XP. Why is it that I can only run 2 of the 3 outputs at once when the card has 3 on it??? Is it possible to run three outputs without buying a second card?
Only the Radeon 5xxx and 6xxx series has Eyefinity which is required to connect 3 monitors. No nVidia card supports more than two monitors.
The reason for the three connections is simply give users options. There are still monitors out there that do not take DVI connections like some cheap LCD monitors and of course those people still using CRT monitors.