^^ Do not use the UD3 especially doing Crossfire, you will get 4x/4x only and that will bottleneck your performance. Your better off getting the UD4P for better results. And I heard Gigabyte's P55A boards when US3 and SATA3 enabled you will lose functionality of the second PCI-E slot and therefore SLI and Crossfire will not work. WTF? So there is another reason to avoid Gigabyte's P55A line.