Hi all. Wondering if anybody has any pointers. So first I’ll explain the ‘my fault’ part of the title. Basically none of these issues occurred before I tried to install a Sapphire RX470. I’m back with the Apple original 5770 now. The 470 worked well when I’d installed the driver which I had to to do every Windows boot but sometimes it prevented me booting to OSX completely, (black screen), especially if I had that and the original 7300GT installed together. My set up - 2010 5,1 I have 3 hard drives currently in my Mac Pro and they are arranged; Bay 1 NTFS Formatted 512GB SSD.(Disk 0). MBR Partition map. Win 10. Bay 2 Bay 3 Bay 4 PCI 2 1TB SSD. (Disk1). GUID Partition map. OSX 10.12.2 PCI 3 60GB SSD. (Disk 2). GUID Partition map. OSX 10.8.5 The Boot manager shows the disks in the following order, (from left to right); 60 (60GB SSD). 112 (1TB SSD). Windows (512GB SSD). Recovery 10.8.5 Recovery 10.12.1 Anyhow, my problems; Every time after booting into Windows, (using option boot), my usual start up disk 112 is not available and the Mac boots into 10.8 that I have installed on a separate SSD in one of the PCI bays. If I go to the ’Startup disk pane’ it doesn’t show there either. IU cannot bless it within 10.8 and when I boot into the 10.12 recovery to sort it I find that SIP has been switched back on despite me having disabled it so I then turn it off the bless works Ok. Also does the Mac have a default boot order? ie if I’d taken two bootable installations from separate machines and inserted the drives and clicked the On button which would the Mac choose to boot if any? Does it go by drive bay/disk name/etc? Cheers.