How Do I Install New Drivers If I Can't Boot Without Drivers?
PROBLEM: If you have installed a new GPU that requires drivers to boot but you have not installed the drivers beforehand your Mac Pro will go into an endless reboot cycle without ever reaching the desktop. If you do not have another GPU handy this may seem like an impossible situation.
SOLUTION: The answer is to not use those drivers and just rely on the EFI driver.
SOLUTION: The answer is to not use those drivers and just rely on the EFI driver.
- Boot into Single User mode by holding "S" and "Command" keys during boot.
- You will see a black screen with a wall of text. At the text prompt type: sudo nvram boot-args="nv_disable=1"
- Press the "Return" key
- At the next text prompt type: reboot
- Press the "Return" key
- Hold the "Option" key as your Mac Pro reboots to choose the boot disk you wish to use. On reboot the Mac Pro will be running on the EFI drivers only. You will notice the screen refreshing via black lines and performance will be sluggish.
- Use this time to visit our driver page and install the appropriate driver for your current version and build of OS X.
- Lastly, open the Terminal application. In the Terminal window type: sudo nvram boot-args="nvda_drv=1"
- Press the "Return" key
- The previous nv_disable command has now been removed and the newly installed driver has been activated. Reboot your Mac Pro and it should boot up normally.