I'm looking at getting a Velocity Duo X2 to run exclusively Windows on in my Mac Pro 5,1 I currently have an XP941 for OS X which runs great. Can anyone who has experience with the Duo tell me if I can install Windows in BIOS mode, and if so does the disk controller run in AHCI? I need to use 'BIOS mode' in my Windows install so that the GTX680ME works correctly. I'm currently running Windows in BIOS mode in bay 3 (SATA2) and Windows insists on using an ATA controller instead of AHCI. Speeds are pretty poor and disk utilisation frequently maxes out at 100% doing basic tasks. What I want is to use the full potential of a Samsung 850 Pro, with Windows in BIOS mode, and with AHCI. Also, are there any know issues with the Duo x2? Boot delays, inability to reboot, hangs, etc? My PCIe slot arrangement would be: Slot1 - GTX 680ME Slot2 - XP941 Slot3 - Velocity Duo X2 Slot4 - Sonnet Allegro Pro USB3.0 Thanks.