The X99 Strix has 2 Sata controllers. The first controls SATA 1,2,3,4 and 5 ports - it is set to AHCI, but supports IDE and RAID too. The second controller controls 6,7,8,9 and 10 ports. It is also set to AHCI, but it also supports IDE only so RAID is not supported on the 2nd controller. The SSD is connected to port 1 and the HDD - to port 3. Both should support AHCI without problems, but that's not the case here.