Without master card...
 
Our sources close to ATI have confirmed that you won't need an X1600 master card to use two of these cards in Crossfire. You can just plug two normal cards in and you will be fine.

We tried this experiment with two X1300 and it worked and it resulted in some significant performance increases. You can check it here and there will be more about this matter.

Apparently ATI cancelled Radeon X1600 PRO master cards, as you simply don’t need them. You will just be able to buy two of those cards place it in two Crossfire ready motherboard slots and you are off to go. We will try to get one more X1600 to show you that it's possible.

They way it goes it might even happen that you don’t need master card even in high end but I guess we will have to wait RD580, two by sixteen PCIe lanes cards to reach that level. We will let you know if that happens.


Source : TheInquirer