This blog post is based on upgrading an external SSD installed on my Big Sur disk (using Patched Sur on my unsupported iMac 27 inch late 2013 – iMac 14.2) to macOS Monterey.  Please note, this does not cover all unsupported Mac devices.  The reason I use an external USB connected SSD disk is that I need multiple macOS environments to test various issues my clients are having.  Also, I do not want to install unsupported macOS on the internal disk of my iMac 27 inch late 2013.  Please also note that Apple does not like a Mac computer having multiple profiles (one machine starts up from different macOS), so please do not connect to iCloud except for the macOS you use for your main production environment.  (After starting up Mojave, Big Sur and Monterey by swapping the startup disk and each time I reconnected iCloud, my Apple ID password was disabled for a security reason – according to Apple)  I had to reset the password while going through a tedious process not mentioning I had to change the Apple ID password for all the other Apple devices including my iPhone and iPad).

As to a genius BenSova’s Patched Sur, please refer to my previous blog post link below.  It covers the latest macOS Big Sur 11.6.7.

Apple Myth 13 – How to install macOS Big Sur (11.2) on unsupported Mac devices

The end result for my macOS Monterey unsupported iMac 27 inch late 2013 is the following images.

Monterey 12.4 running on unsupported iMac

Monterey 12.4 running on unsupported iMac

Monterey Software Update

Monterey Software Update

My iMac 27 inch late 2013 is enrolled in the Apple Developer Program (happened a long time ago).  OpenCore Patcher disguises Apple where unsupported Mac devices can still get the latest macOS updates.  macOS 13 Beta is the next version of macOS Ventura.  If I click Upgrade now, then my OpenCore patched Monterey system will be destroyed.  I will post on my next blog post regarding the next macOS Ventura in conjunction with the OpenCore patcher.

Monterey Developer Update

Monterey Developer Update

Being involved with the Apple Developer Program, my iMac 27 inch late 2013 also showed the Monterey Developer update before the public Beta test.  However, I’ve decided not to apply any Beta updates as I’m using Monterey with my unsupported iMac on my main production Mac and taking the Automatic Update option off.  I will wait until the public release of Monterey 12.4 to get to version 12.5.

Update: 30/07/23

OpenCore Legacy Patcher Team released ver 0.6.8 recently.

After updating macOS Monterey 12.6.3, I had constant issues applying any macOS Monterey update as my USB connected 1TB SSD system drive saying “downgrade volume not possible” whenever I tried OS update.  Uninstalled a few suspected non compatible programs, I finally could update the system to Monterey 12.6.8.

You can download the installation program from the following link.

https://swcdn.apple.com/content/downloads/50/44/042-15015-A_XSTTRTW8H4/cu5mniyv6jsu0h806qoqt5qtlu6l7f46w6/InstallAssistant.pkg

(If you would like to download the above full package, please copy paste the above link in a new tab. Otherwise, download will not start. )

Monterey 12.6.8 running on unsupported iMac

Monterey 12.6.8 running on unsupported iMac

Update: 02/02/23

OpenCore Legacy Patcher Team released ver 0.6.1 recently.  For whatever the reason, I could not update macOS Monterey 12.61 to 12.62 as 12.61 installed external 1TB SSD said “downgrade volume not possible”.  But when I tried the latest 12.63 release on the installation USB 3 disk combination of OpenCore Legacy Patcher 0.61, Monterey update was successful.

Link for macOS 12.63 full installer package is as follows;

https://swcdn.apple.com/content/downloads/17/14/032-33828-A_KX25OQBX8S/lz9yip4rmenyju8nkv4wpaqtdmvzfogkcb/InstallAssistant.pkg

(If you would like to download the above full package, please copy paste the above link in a new tab. Otherwise, download will not start. )

Monterey 12.63 running on unsupported iMac

Monterey 12.63 running on unsupported iMac

Update: 05/11/22

OpenCore Legacy Patcher Team released ver 0.5.1 recently.  This is a major break through enabling unsupported Mac computers to run macOS Big Sur, Monterey and Ventura.  This patcher is amazing!

  1. Created Monterey installation USB 3 disk using Monterey 12.51 (Beta) environment.
  2. Simply started my unsupported iMac 27 inch 2013 with the USB installation disk.
  3. Updated Monterey 12.51 to 12.61
  4. Upon restarted the system, everything worked like a charm. (including Nvidia GPU acceleration)
  5. Restore form Time Machine backup now works perfectly.

Monterey 12.61 full package download link;

https://swcdn.apple.com/content/downloads/36/13/012-90254-A_BJQ1VMPD44/z225i7bzise31eo21e4kgfkafz7zq0q9tu/InstallAssistant.pkg

(If you would like to download the above full package, please copy paste the above link in a new tab. Otherwise, download will not start. )

Monterey 12.61 running on unsupported iMac

Monterey 12.61 running on unsupported iMac

Please refer to the following Youtube link (by very talented Mac specialist Mr. Macintosh).

OpenCore Legacy Patcher 0.5.1 Update Ventura Support+ Monterey 12.6.1 & Big Sur 11.7.1 How to update

As to macOS Ventura, please refer to my other Blog post.

Warning!!! (This has been solved by OpenCore Legacy Patcher 0.5.1)

Starting from macOS Monterey 12.5 Beta 3 update, Apple has taken away Graphic Card Acceleration support for Nvidia GPU known as Nvidia Kepler (Like my iMac 27 inch 2013 with Nvidia GeForce GTX 780M 4GB – iMac 14.2).  The latest Monterey 12.5 public release updates the system, but once OpenCore Legacy Patcher applies root patch then restart the system, it goes into login loop and the Mac computer becomes unusable.  Recommendation for an unsupported Mac computer with Nvidia Graphic Card should stay with Monterey version 12.4.

For more details, please visit the following Macrumors Forum

macOS 12 Monterey on Unsupported Macs Thread

Update: 20/08/22

OpenCore Legacy Patcher Team released version 0.4.10 fixing  Macs with Nvidia Kepler issues.  Both macOS Monterey 12.5 and 12.51 update work on unsupported Macs with Nvidia GPU acceleration.

Monterey 12.51 running on unsupported iMac

Monterey 12.51 running on unsupported iMac

Full installer download link (ver 12.51)

https://swcdn.apple.com/content/downloads/18/44/012-51693-A_2W745BUZP7/xtd63whw506llesta7af6cjvcxlyj8mxvf/InstallAssistant.pkg

(If you would like to download the above full package, please copy paste the above link in a new tab. Otherwise, download will not start. )

But after 12.5 or 12.51 update on my unsupported iMac 27 inch late 2013, try to restore full from Time Machine backup using fresh install 12.5 or 12.51 + Migration Assistant fails when my iMac restarts at the end.

It goes into start up loop and user folder creation fatally fails.  Noone has reported this on Macrumors Forum macOS 12 Monterey on Unsupported Macs Thread as yet.  Interestingly, Time Machine Backup for both 12.5 and 12.51 restore succeeds if you use 12.5 Bata fresh install + Migration Assistance.  As you can no longer download 12.5 Beta or 12.5 Beta2 from Apple, you’d better stay with 12.4 while you can still download the full installer from Apple if your Mac has Nvidia GPU.

Full installer download link (ver 12.4)

https://swcdn.apple.com/content/downloads/16/08/012-06873-A_636SHHRD4L/528ojpmw00mulgfjsz9k50modkj31a9v0p/InstallAssistant.pkg

(If you would like to download the above full package, please copy paste the above link in a new tab.  Otherwise, download will not start. )

Just in case you need to roll back Monterey 12.5 or 12.51 to Monterey 12.4

a. Create a full Time Machine backup to an external drive
b. Create OpenCore EFI based Monterey 12.4 full installer on an USB stick
c. Shutdown the system
d. Start your Mac from Monterey 12.4 based USB installer
e. Erase volume group with disk utility
f. Erase the drive and create APFS blank drive with disk utility
g. Install Monterey 12.4 and use Migration Assistant using Time Machine backup
h. Discard a message pop up for Time Machine version warning
i. Finish the migration and restart the system

You are all set.

Part I. Basics

Which Macs can run macOS 12 according to Apple? (Monterey)
12-inch MacBook (early 2016 and later)
MacBook Air (early 2015 and later)
MacBook Pro (early 2015 and later)
Mac mini (late 2014 and later)
iMac (late 2015 and later)
iMac Pro (2017 and later)
Mac Pro (late 2013 and later)

But OpenCore Patcher opens the door for older Mac computers to run macOS 12 Monterey.

Please take a look at the following links before you start. Although video clips are relatively old, they still stand out as a great source of information.

Thank you to a very talented Mac Specialist Mr. Macintosh.

a. How to Upgrade from Big Sur to Monterey & Update OCLP OpenCore Legacy Patcher – Unsupported Mac!

b. Monterey on Unsupported Mac [2008-2015] OpenCore Legacy Patcher!!!

c. Create a Bootable macOS Monterey USB Installer IN 5 MIN!!!

Part II. OpenCore Legacy Patcher

You should always keep up to date with the OpenCore Legacy Patcher.  Please download the latest version from the following link.

OpenCore Legacy Patcher

Part III.  What I did

a. Using an external Patched Sur (Big Sur) installed SSD to start up the system.  (I used Super Duper! to clone the original Big Sur external disk)

b. Downloaded OpenCore Legacy Patcher

c. Started OpenCore Legacy Patcher and updated EFI of the Big Sur installed disk

Install OpenCore on an external Big Sur SSD disk

Install OpenCore on an external Big Sur SSD disk

Choose External 1TB Big Sur Installed SSD

Choose External 1TB Big Sur Installed SSD

d. Created standard Monterey installable USB 3 stick (16GB)

Full installer download link (ver 12.4)

https://swcdn.apple.com/content/downloads/16/08/012-06873-A_636SHHRD4L/528ojpmw00mulgfjsz9k50modkj31a9v0p/InstallAssistant.pkg

The above link is no longer available.

Once the full InstallAssistant.pkg download was complete, I simply ran the package program and chose the External 1TB Big Sur Installed SSD and the installer application was placed in the Applications folder.

Connected an USB 3 stick with at least 16GB capacity.

Then ran the terminal program;

sudo /Applications/Install\ macOS\ Monterey.app/Contents/Resources/createinstallmedia –volume /Volumes/”Name of the USB Stick”

e. Restarted the system holding alt key whilst connecting to the USB stick with Monterey installer.

Chose the EFI loading button then started the USB stick base Monterey installer.

Everything went well successfully upgraded Big Sur to Monterey.  After that, all I had to do was to apply Post-Install Volume Patch under OpenCore main menu and updated Nvidia Graphic Card drivers and restarted the system.

Post-Install Volume Patch

Post-Install Volume Patch

I did not create OpenCore EFI installed USB 3 installer stick (I did it afterwards).

Part IV. Patched Sur vs OpenCore

Biggest benefit to using Patched Sur (Big Sur) is cloning with Super Duper!  Whilst OpenCore installed the external disk cannot be cloned with SuperDuper! (Carbon Copy Cloner also fails).  I’m still looking for software which can clone OpenCore installed on to an external disk as I do not use the Time Machine backup (waste of time).

Biggest benefit to using OpenCore installed Monterey is the version update.  It can be updated even for an incremental update (not a full update) just like an ordinary Mac computer. But make sure you check before any updates that the OpenCore Patcher is the latest version.

17/06/22

OpenCore team just released ver 0.4.7.  GUI interface application only (OpenCore-Patcher-GUI.app.zip) and no more Terminal base application is available.

OpenCore Legacy Patcher

Replaced 0.4.6 Terminal application with ver 0.4.7.  Updated EFI partition and applied system volume patch.  It’s working fine.

20/07/21

Apple Developer Program released macOS Monterey 12.5.  It appears OpenCore Legacy Patcher (current version is 0.4.8) does not support this version as yet. (I tested with my unsupported iMac 27 inch late 2013).  After the macOS update, if I apply Root Patch by OpenCore Legacy Patcher, after the restart I cannot login to the system and it goes into login loop.  I created Monterey testing environment on a separate USB attached SSD.  The current OpenCore Legacy Patcher works up to Monterey 12.5 Beta 2 (I have not yet tested Beta 4), but Beta 5 and this 12.5 (appears to be final – not as yet released to the public) will fail to start up.  So, you’d better wait until OpenCore Legacy Patcher supports Monterey 12.5.

macOS Monterey 12.5 Beta2

macOS Monterey 12.5 Beta2

macOS Monterey 12.5

macOS Monterey 12.5

21/07/22

Opencore Legacy Patcher team released version 0.4.9 where the team acknowledge the issue with a Mac has Nvidia GPU.  In the release note, the team say “Warning for Macs with Nvidia Kepler: macOS 12.5 breaks graphics acceleration with this build”.  The team further say “Stay on 12.4 or older if your Mac has a Kepler GPU. 0.4.9 will prevent the installation of Kepler acceleration patches, instead only installing basic framebuffer in 12.5. macOS 12.4 and older are not affected, and can still be used normally.”

If you need help for Mac computers  (Sydney CBD, Sydney North Shore – particularly in Carlingford, Epping, Chatswood, Roseville, Lindfield, Killara, Gordon, Pymble, Turramurra, Wahroonga, Warrawee, Hornsby, Macquarie Park and St Ives area) please contact Harry 0417 424 909.  Or refer to our Service page.

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