yes, the mastercard has one dvi and one crossfire connector, whereas the slave (the ones you would normally buy) have two dvi.(my experience with x1900 only...may be different for lower cards)
basically, look at the back of the card, if there is a connector you cant identify, and it came with some big thick splitter-type cable, then you have a mastercard. (this is for x1900 series cards)
