I want to add a third monitor (not for gaming) (will operate independently) I have a D945GNT board, what is important to look for as far as matching it to my board?
We would like to inform you this motherboard has been discontinued.
Regarding your question I can tell you that besides having a power supply that provides enough wattage to handle a 2nd video card on your system there is not much to look for.
So depends on the video card you are getting, you may need to get a new power supply also
We can recommend having the latest BIOS version installed. However if your system is working fine, a BIOS update is not necessary.