I'm running a Mac Pro 5.1 with a GTX 970 and a GT 120 installed. I've just wiped the SSD and now I'm stuck wrangling with MacOS's hyper-specific install requirements.

High Sierra won't let me install on the APFS partition it set up for itself previously so I'm trying to get to a point where I can reformat the drive entirely, but of course the recovery partition is mounted preventing me doing so.

The High Sierra USB install seems to have a common bug where it won't recognise the bluetooth mouse or keyboard. I have a wired mouse that its missing also. So that's a non-starter.

It seems my only option is Internet Recovery. However, holding alt+cmd+R just results in a black screen. EDIT: Looks like my model of mac doesn't support it at all, thanks David

Does anyone know the best course of action?

  • 1
    If your MacPro5,1 is a 2010 model, then I do not think you can use Internet Recovery. See Computers that can be upgraded to use OS X Internet Recovery. Feb 27, 2019 at 15:05
  • Ah well that's something to cross off!
    – dnv
    Feb 27, 2019 at 15:07
  • 1
    Have you tried installing to an external drive using a different Mac? If you can, then you could run from the external drive and reinstall macOS on the internal drive. Feb 27, 2019 at 15:10
  • I did try, it spits out an error stating that it can't install as there is no firmware partition on the drive.
    – dnv
    Feb 27, 2019 at 15:11
  • If you can get to 'onboard' recovery, from the existing partition on the SSD, can't you simply reformat the APFS container back to an HFS+ volume? iirc, HS wants to see HFS, then do its own conversion as part of the install.
    – Tetsujin
    Feb 27, 2019 at 17:41

1 Answer 1


In the end, I resorted to creating a time machine backup of a working machine and using that to restore in recovery mode.

If you get stuck at the installer image telling you to turn on your bluetooth mouse, ensure that both a wired keyboard and mouse are plugged into the front.

I couldn't get it to clean install with any of the suggested workarounds. External drives and DVD images aren't supported for the High Sierra installer, nor can you reformat to HFS+. It's a stubborn pig of an OS. I'm now wrestling with getting the nvidia web drivers to work again. Thanks for all your responses.

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