I failed to upgrade the firmware on my Mac Pro 2009 (flashed to MacPro5,1). After the regular firmware update procedure (flickering light, beep, 5 minute wait, automatic reboot), the firmware is still MP51.007F.B03.
Since I'm using a Radeon RX 580, I don't have a bootscreen and can't tell if the progress bar is actually displayed and/or if a kernel panic occurs somewhere along the way.
What I've tried (unsuccessfully):
- Removing external devices
- Removing PCIe SSD
- Removing PCIe USB 3 Adapter
How long did the firmware upgrade take for you?
PS: No need to peek at the EFI partition. The firmware files are also found in the installer package in
/Contents/Resources/Firmware.