From the Diamond web page...

1 Dual Link DVI, 1 Single Link DVI, HDMI and 2 Mini Display Port

So I'm guessing here,

1 monitor on the Dual Link DVI, 1 on the single link DVI (which would be shared with the HDMI, and then 1-2 on the Mini Display port.

I think that is right, but hopefully Fenril or one of the other guru's will come along and Confirm or correct this.

Stephen