I have two Sapphire Radeon 280X in crossfire on a ASUS P9X79 motherboard. The motherboard has the latest BIOS installed. The thing is that when I look in to the hardware specs in the Catalyst Control Center, I notice something strange. The card listed as the primary adapter shows its PCIe setting as 3.0, while the one listed as linked adapter only shows its setting as PCIe 2.0. What can I do to solve this?