#BOOTCHAMP HIGH SIERRA NOT WORKING INSTALL#

I know my post is quite long and this is quite a complicated and rare problem. I tried to enable the Option ROM firmware with no avail. I could get away (possibly) with a GT120 but I should be able to get to the startup manager anyway. For the moment I can't have both cards at the same time.

The only solution to get back to the macOS is to reset the NVRAM but then the card doesn't work because it'll have switched back to the old driver. Of course I can't see anything which doesn't help. I think it must get stuck because of the odd partitioning.

#BOOTCHAMP HIGH SIERRA NOT WORKING INSTALL#

And I think this is why I'm having so many issues.Īnd if I install the non-EFI GPU (in this case a 1080Ti), the Startup manager does not work full stop. Something else must be broken on this partition. This means I can't use BootChamp to switch to Windows from the macOS. If I select 'EFI Boot' from the Startup Manager, all works fine. But if I select 'Bootcamp' (not EFI Boot') in System Preferences/Startup Disk the Mac reboots to a black screen with a message: 'no bootable device insert boot disk and press any key'. Here's what's happening with the original ATI Mac card.īy holding the option key, I can select either 'Macintosh HD', 'EFI Boot' or the recovery partition. Funny how Apple 'forgot' to patch it to say macOS. Bootcamp drivers work and I am able to restart in 'OSX'. I was able to install Win 10, all went smoothly. I then had to fix the partition scheme because HS broke some functionality that converts it to a hybrid MBR/GUID partition table. I installed Windows 10 by 'patching' the Bootcamp Assistant app.

I installed Sierra and then upgraded to High Sierra. I added a Mac Pro 5,1 to the fleet a month ago. All my (modern) Apple devices have been working flawlessly, until now. It's been a while since I posted anything here. I know that you can't see the startup manager screen with a non EFI card.

Bootchamp high sierra not working