I have a ASUS P6X58D Premium motherboard in my newly built system. The motherboard is not recognizing my two SATA 6 HDD's, plugged into the SATA 6gb/s ports (with the included SATA 6 cables) at least in the BIOS it says "not detected". But when I start up it does detect them on the "startup" text screen (sorry this is my first PC, I was a Mac guy). The HDD's are Seagate 2TB, one a Seagate Barracuda St320005N1A1AS-RK 2TB 7200 RPM 64MB Cache SATA 6.0Gb/s 3.5" & the other is a Seagate Barracuda XT ST32000641AS 2TB 7200 RPM SATA 6.0Gb/s 3.5". The motherboard however is recognizing however my blue-ray, DVD, and two SSD drives. These however are plugged into the 3gb/s SATA ports. Now for the weird thing, I formatted the Seagate HDD's and Windows 7 recognizes them, but still not the motherboard. Any help would be appreciated! Thanks!