Well you can connect up to four monitors straight onto the card, the first two using any combination of DVI/HDMI/VGA, the other two using the two DP outputs.
But it says on the page you linked:
Quote:
Up to 6 displays supported with DisplayPort 1.2 Multi-Stream Transport
So it should go up to 6, i believe you can buy a sort of hub that you connect to one of the DP ports that gives you a few more DP ports (pretty much like you can with USB). But you'd have to look into that, or someone else may have to pop in on that since i have've never looked into that myself
