Installing macOS Big Sur 11 on unsupported Mac Pro

 

Make sure to have Boot ROM 144.0.0.0 installed. If not please follow this guide: Installing macOS Mojave 10.14 and performing Mac Pro 5,1 Boot ROM update

 

We recommend macOS Big Sur 11.2.3 since newer versions introduced a race condition bug causing older Mac Pro's not to boot everytime.

 

If you have boot issues post installation like no entry symbol, you need to click EFI boot icon in boot picker to set NVRAM variables again. Then the system will boot normally.

 

Step 1

Download macOS Big Sur 11.2.3 from here and unpack zip file it to Applications folder.

Installing macOS Big Sur 11 on unsupported Mac Pro
 
 

Step 2

Insert USB stick to any USB port. It must be at least 16 GB in size.

 

From Finder menu click Go, then Utilites and double click Disk utility icon.

 

Select your USB stick from the left menu and click Erase button.

 

Type MyVolume in name field and select Mac OS Extended (Journaled) as format and GUID Partition Map as scheme. Then click Erase button to erase USB stick.

Installing macOS Big Sur 11 on unsupported Mac Pro

 

 

Step 3

Visit https://github.com/barrykn/big-sur-micropatcher and click Code button then Download ZIP link.

 

The downloaded file should be automatically unpacked inside Downloads folder.

Installing macOS Big Sur 11 on unsupported Mac Pro
 
 

Step 4

In Finder choose Go, then Utilites and double-click Terminal icon to launch Terminal.

Installing macOS Big Sur 11 on unsupported Mac Pro
 
 

Step 5

Create bootable USB installer by typing a following command (all in one line), then press ENTER:

 

sudo /Applications/Install\ macOS\ Big\ Sur.app/Contents/Resources/createinstallmedia --volume /Volumes/MyVolume

 

Terminal will ask for password. Type your user password and press ENTER (password won't be shown not even under asterisk).

 

Creating bootable USB installer will take about 15-50 minutes depending on USB stick write speed.

Installing macOS Big Sur 11 on unsupported Mac Pro
 
 

Step 6

As soon creating bootable USB installer is finished type another commands in Terminal to patch it and press ENTER after each of these (every command in one line):

 

cd Downloads/big-sur-micropatcher-main

 

sh ./micropatcher.sh

Installing macOS Big Sur 11 on unsupported Mac Pro
 
 

Step 7

Finally enter such command and press ENTER (all in one line):

 

sh ./install-setvars.sh

 

Terminal will ask for users password (it won't be shown not even under asterisk).

 

Your USB installer is now patched.

Installing macOS Big Sur 11 on unsupported Mac Pro
 
 

Step 8

Reboot your computer.

 

Press and hold Option key (on Mac keyboard) or ALT key (on Windows keyboard) and click an arrow under EFI boot icon.

 

Computer will be turned off automatically. This will set all proper NVRAM values needed for macOS Big Sur.

Installing macOS Big Sur 11 on unsupported Mac Pro
 
 

Step 9

Power on your computer again.

 

Once again press and hold Option key (on Mac keyboard) or ALT key (on Windows keyboard) and click an arrow under Install macOS Big Sur icon.

 

This time click an arrow under Install macOS Big Sur to start macOS Big Sur installer.

Installing macOS Big Sur 11 on unsupported Mac Pro
 
 

Step 10

If you haven't created blank APFS partition needed for macOS Big Sur yet, you can create one now by choosing Disk Utility.

Installing macOS Big Sur 11 on unsupported Mac Pro
 
 

Step 11

If you have APFS partition ready, you can select Install macOS Big Sur and click Continue button to start the installation.

 

Continue macOS installation just like on a supported Mac. The system will reboot several times automatically during installation.

Installing macOS Big Sur 11 on unsupported Mac Pro
 
 

Step 12

When installation is ready you will be presented with Migration Assistant. Leave the default radio button as is and just click Continue button.

Installing macOS Big Sur 11 on unsupported Mac Pro

 

 

Step 13

Now you can move data from your old macOS installation. Click your previous macOS drive and then Continue button.

Installing macOS Big Sur 11 on unsupported Mac Pro

 

 

Step 14

As soon your data is moved and you will see macOS Big Sur desktop, you need to reboot once again to patch kexts e.g. for Wi-Fi module to be operational.

 

Once again press and hold Option key (on Mac keyboard) or ALT key (on Windows keyboard) and click an arrow under Install macOS Big Sur icon.

 

macOS Installer will start again. Choose Utilites from Finder and then Terminal.

Installing macOS Big Sur 11 on unsupported Mac Pro

 

 

Step 15

Type a following command in Terminal and press ENTER to start patching kexts (all in one line):

 

"/Volumes/Image Volume/patch-kexts.sh" "/Volumes/BIG SUR"

 

where BIG SUR is your macOS Big Sur partition name.

Installing macOS Big Sur 11 on unsupported Mac Pro

 

 

Step 16

As soon patching kexts is finished your can reboot in normal mode and macOS Big Sur will be fully functional just like on a supported Mac. Enjoy!

Installing macOS Big Sur 11 on unsupported Mac Pro