Question: Issue Causing iMac Pro Not To Boot Into Windows 10 Identified
On December 26, 2017 I received a new iMac Pro and a Promise Pegasus3 R6 raid 5 array. I configured my iMac Pro with a Western Digital My Book thunderbolt 2 hard drive (connected to the iMac Pro using Apple's thunderbolt 2 to thunderbolt 3 adapter), the Pegasus3 R6 connected via a thunderbolt 3 cable which came with the Pegasus3, and two Western Digital USB3 hard drives. I also installed Windows 10 using Bootcamp Assistant. I reported back in January on this Forum that I was unable to boot into Windows 10 on the iMac Pro. When attempting to do so, I would get to the Windows logo screen and the spinning circle of white dots, but the boot would never continue beyond this point.
I have now been able to determine that this problem is directly attributable to the Pegasus3 R6. When it is attached to the iMac Pro, I can never get beyond the Windows 10 logo screen and the spinning circle of white dots. Removing the Pegasus3 R6 from the iMac Pro and it immediately boots into Windows 10 every time without issue. The correct driver for Windows 10 for the Pegaus3 R6 (downloaded directly from the Promise site) is installed and has not solved this issue. Once I have booted into Windows 10 without the Pegasus3 R6 attached) I can then plug in the Pegasus3 R6 and it will function without any problems.
I have been working with Promise Support now for two months to resolve this issue, bu two far no solution form Promise Support has been forthcoming.
Finally, I should point out that I have had access to a second iMac Pro and the exact same issue has occurred upon trying to boot into Windows 10 with the Pegasus3 R6 attached to that iMac Pro.
iMac Pro, macOS High Sierra (10.13.2), 2 TB flash ram, 64 GB, Vega 64 Pro