I just built my first computer. I have my Gigabyte Radeon R9 270X plugged into my ASRock Z97 Pro3 via the PCIe2 slot. It's got power via two six-pin connectors to my Seasonic S12II 620w power supply. My motherboard reports that my PCIe2 slot is completely empty via the ASRock hardware monitor software and the BIOS, but the Radeon is connected and powered and the fans are spinning. It's Windows 8.1, and when I run the Catalyst Install Manager to install drivers, it also does not detect my graphics card. What gives? Thanks for your time.