Hey, I was just wondering if anyone could help me. I have a M3A790GXH/USB3, and am looking to buy a graphics card to go with it. On the ASRock website there's a list of all CrossFireX compatible graphics cards, (Here, if you're interested) and I was just wondering if this is the absolute list, or just a list of checked ones. So for example would I be able to run a pair of Sapphire HD 5770s in CrossfireX? And similarly, the list also specifies the model and size of the card. Is this mandatory?

Thanks in advance.