macOS Monterey was released a few days ago. Just as with most new releases of macOS, also for macOS Monterey, Apple decided to remove official support for some of the older Mac hardware. In general anything older than a 2015 model is no longer supported. This doesn’t necessarily mean that those Mac models cannot handle the new operation system, in most cases it would run it just fine. Luckily, if you want to, there are always ways to get around these restrictions. In this article, I will describe step by step how to install macOS Monterey on officially unsupported models by using OpenCore Legacy Patcher.
Newer version of macOS: Sonoma
Although this post is still very relevant, in the meanwhile, macOS Sonoma has been released. A very similar method is available to install the latest version of macOS on unsupported hardware. I did a separate post that covers that version of macOS, so have a look at it over here if you are interested.
If you are interested, I also created a YouTube video from this blogpost. If you prefer classic text, you can just follow the rest of this article:
In an earlier post, I described how to install the predecessor of Monterey, Big Sur, on unsupported models. I used MicroPatcher for that article and mentioned BigMac there as well. For this article, I will go for a different method and I will use OpenCore Legacy Patcher to get around the hardware checks.
In contrast to MicroPatcher, this method uses an unmodified macOS installer. Instead, it tricks the installer in thinking it is running on a newer, supported, model.
You can find a comprehensive list of models on which OpenCore is supported over here: https://dortania.github.io/OpenCore-Legacy-Patcher/MODELS.html
The minimum OS version installed needs to be 10.9 (Mavericks)
For hardware without Metal support, using a patch, the following should work:
- MacBook5,1 (Late 2008) and later
- MacBookAir2,1 (Late 2018) and later
- MacBookPro4,1 (Early 2008) and later
- Macmini3,1 (Early 2009) and later
- iMac8,1 (Early 2008) and later
- MacPro3,1 (Early 2008) and later
With Metal support, everything newer than the following is fine:
- MacBook8,1 (Mid-2015) and later
- MacbookAir6,1 (Mid-2012) and later
- MacBookPro9,1 (Mid-2012) and later
- Macmini6,1 (Late 2012) and later
- iMac13,1 (Late 2012) and later
- MacPro4,1 (Early 2009) and later (with Metal GPU)
Overview of the process
For the article, I will be using a Late 2013 iMac with model identifier iMac14,2. My model has the highest specced CPU: an i7 4771, a 256GB SSD, 16GB RAM and the NVIDIA GeForce GTX 780M with 4 GB. This is interesting as support for NVIDIA GPUs has been mainly removed in Monterey. It was running macOS Catalina as a starting point, which is the last officially supported release on this model.
The steps we need to go through are the following. These need to be executed on the device where you would like to install Monterey.
- Download the Install macOS Monterey app without using the App Store
- Create a bootable USB drive for macOS Monterey
- Build and install OpenCore on the USB drive
- Boot from the USB drive and install macOS Monterey
- Install OpenCore on the SSD/hard drive
- Optionally install patches (mainly for non-Metal or non-supported GPUs like my NVIDIA card)
Step 1) Download the Install macOS Monterey app without using the App Store
The first step in this whole process, is to get our hands on the installer. As the device which we want to get Monterey on is officially not supported, the installer for Monterey will not be shown in the App Store on this device. So we need to find another way to get our hands on InstallAssistant.pkg for Monterey.
Mr. Macintosh keeps a list with versions and links to directly download the InstallAssistant.pkg file. You can find this here: https://mrmacintosh.com/macos-12-monterey-full-installer-database-download-directly-from-apple/:
At the time of writing, the latest and release version was 12.0.1 (build 21A559) and I used the following link to download the package from Apple: https://swcdn.apple.com/content/downloads/39/60/002-23774-A_KNETE2LDIN/4ll6ahj3st7jhqfzzjt1bjp1nhwl4p4zx7/InstallAssistant.pkg
Once you have downloaded the .pkg, you can double-click on it and run through the dialogs to install “Install macOS Monterey” to your Applications folder:
In case you would encounter issues due to any hardware checks (I did not experience any on my iMac), you can also manually extract the .app from the .pkg and move the .app to your Applications folder. You can use the following command in terminal for that.
jensd@jensds-iMac ~ % cd Downloads jensd@jensds-iMac Downloads % pkgutil --expand-full InstallAssistant.pkg monterey/ jensd@jensds-iMac Downloads % mv monterey/Payload/Applications/Install\ macOS\ Monterey.app /Applications/
If this went well, you should now have the Install macOS Monterey application in your Applications folder. This is what we need for the next step:
Running this just like on an unsupported model, like mine, won’t work as you will get a “The update cannot be installed on this computer” during the installation:
Step 2) Create a bootable USB drive for macOS Monterey
Now that we have the installer downloaded and ready, we will use it in this step to create a bootable Monterey installation USB.
First we need to prepare the USB drive to make sure we can boot from it and patch it with OpenCore in the next steps. To do so, insert the USB drive and open Disk Utility. In Disk Utility, click to show All devices:
Then, in the left column, select your USB drive and click Erase on the top menu. Now give the drive a name, I chose 32GBUSB, select Mac OS Extended (Journaled) and GUID Partition Map as scheme and click Erase:
When this is done, we can use the installer to prepare the USB and get files on it. Open a terminal window and execute the following command:
jensd@jensds-iMac ~ % sudo /Applications/Install\ macOS\ Monterey.app/Contents/Resources/createinstallmedia --volume /Volumes/32GBUSB Password: Ready to start. To continue we need to erase the volume at /Volumes/32GBUSB. If you wish to continue type (Y) then press return: y Erasing disk: 0%... 10%... 20%... 30%... 100% Making disk bootable... Copying to disk: 0%... 10%... 20%... 30%... 40%... 50%... 60%... 70%... 80%... 90%... 100% Install media now available at "/Volumes/Install macOS Monterey"
This can take some time, depending on the speed of your USB drive. In case you called your drive different when erasing it within Disk Utility, you will need to adapt this in the command here.
At this point, we have a standard bootable USB drive for installing Monterey. This one could be actually be used now to install Monterey on supported hardware.
Step 3) Build and install OpenCore on the USB drive
From here we start with the steps that are needed to overcome the fact that our hardware is no longer officially supported. We will use OpenCore Legacy Patcher for that.
OpenCore is a bootloader that is often used for Hacintosh builds but it runs on real Apple hardware just fine as well. OpenCore patches or changes some data in memory, making the software think it is running on newer hardware and by this bypasses any restriction.
To start with this, we first need to download the latest version, which can be found here: https://github.com/dortania/Opencore-Legacy-Patcher/releases
As you can see, there is a graphical version (OpenCore-Patcher-GUI.app.zip), an offline text-based version (OpenCore-Patcher-TUI-Offline.app.zip) and a text version (OpenCore-Patcher-TUI-Offline.zip). That last one, the regular text version, will do just fine.
After downloading OpenCore-Patcher-TUI.app.zip, extract it by clicking on it in Finder and open the application. You should see a terminal window now with several options:
We need to start with option 1) Build OpenCore:
This shouldn’t take very long. As you can see in the output, this has built OpenCore specifically for the Mac model which we are working on (iMac14,2 in my case).
Press Enter to go back to the main menu and now choose option 2) Install OpenCore. After entering this option, select your USB drive from the list (disk3 in my case):
In the next screen, select the only EFI partition which exists on that drive:
This will install the OpenCore bootloader to the EFI partition on the USB drive. In a later stage, we will repeat this process but for the internal drive in our Mac.
Step 4) Boot from the USB drive and install macOS Monterey
Boot OpenCore and launch the installation
The USB drive is fully prepared in the previous three steps. Now it is time to boot the Mac from the USB drive in order to install Monterey. To do so, reboot your Mac and hold down the Option key during boot time.
Holding down the Option key brings up the bootloader. In there, you should see the currently installed system (named Catalina in my case), an entry to install Monterey and an EFI boot entry with the OpenCore logo. The last two are on our USB drive.
From here, the standard bootloader, we can’t start the installation as we need to do this from OpenCore to hide the real system identifier. Instead, select the EFI boot entry using the arrow keys and press enter:
This brings you in OpenCore, which looks very similar to the standard bootloader. THe only difference is the text at the right bottom corner. From here you can now choose the “Install macOS Monterey” option:
This will launch the installer from the USB drive, which can take some time. Once you arrived in the installer, you should see something like this:
Prepare your internal SSD/HD for the installation
At this point we need to decided where we will install Monterey:
- Fresh install: remove the existing installed system, and give the full drive to Monterey
- Dual boot: add a new Volume and resize the existing one(s) to keep your current macOS and add Monterey
- Upgrade: upgrade your existing installation
For the first two, we need to launch Disk Utility first from the menu as we need to prepare our drive. In Disk Utility, first click on the button to show All devices:
For option 1, to go for a single OS and do a fresh install of Monterey, click your drive (internal SSD/HD) on the left side and click Erase. Give your drive a name (I chose Monterey), choose APFS as Format and GUID as scheme:
For option 2, to add Monterey together with your current macOS install, click your drive (internal SSD/HD) on the left side and click Partition. Click the plus sign here to add a partition and choose to add a partition rather than a volume.
You can change the size on the left side, name the volume (I chose Monterey) and choose APFS as format:
As soon as Disk Utility is ready with the operations on the drive, we are good to move to the next step.
Now that our disk is prepare, or you decided to upgrade the existing install, you can start the installation from the menu:
Click Continue, accept the license agreement and select the volume on which you want to install Monterey. Here you need to select:
- Fresh install: the only internal volume you see here (called Monterey in my example)
- Dual boot: the volume which you added during the partition part (called Monterey in my example)
- Upgrade: select the volume which you want to upgrade (called Catalina in my case)
From here on, you can relax and sit back as the installation can take quite some time. If all goes well, you should see the following screen after a series of reboots:
Navigate through the questions, which differ depending on which type of install you decided to go for. You can notice in some cases that everything is pretty slow. This is due to the lack of video card drivers or Metal support. which we will fix in step 6.
If all goes well, you should end up on the desktop of your newly installed macOS Monterey system:
Step 5) Install OpenCore on the SSD/hard drive
So far we have successfully installed Monterey on our Mac. But to start it, we still need to boot from the USB drive as that is where OpenCore is currently installed. In order to fix this, we need to install OpenCore to the internal HD/SSD instead.
This goes in the same way as we did in step 3) for the USB drive. We first need to download the latest version of the OpenCore Legacy Patcher, which can still be found here: https://github.com/dortania/Opencore-Legacy-Patcher/releases
Again, download OpenCore-Patcher-TUI.app.zip, extract it by clicking on it in Finder and open the application. In the terminal window, we again need to start with option 1) Build OpenCore:
Once complete, go back to the main menu and now choose option 2) Install OpenCore. Here we now need to select our internal drive (SSD or HD) instead of the USB drive:
In the next step, select the EFI partition on it:
Just as in step 3, this will install the OpenCore bootloader to the EFI partition, allowing the official bootloader to boot from it:
At this point it is safe to eject and remove your USB drive. In case you have a fully supported (AMD-based) graphical card, you should be done here and you can do a reboot to test if everything still works.
In some cases it might be needed to boot holding the Option key, then select OpenCore.
Step 6) Optionally install patches
If the model of Mac which you are using doesn’t have a Metal-supported card or you are having one of the NVIDIA-based models where Apple decided to remove support for, you need to go through this additional step.
In this step, we will install some patches ion the system that will either add graphics acceleration for non-Metal card or fix the driver issues for others.
Re-launch the downloaded OpenCore legacy patcher, which you downloaded in the previous step. Now choose for option 3) Post-Install Volume Patch:
Then select 1) Patch System Volume:
Depending on which patch is needed for your system, a selection will be made and applied after confirmation.
After going through this, perform a reboot and you should be done. In some cases it might be needed to boot holding the Option key, then select OpenCore.
As I wanted to check if there would be any performance impact after upgrading to Monterey, I did a Geekbench 5 test on my system while it was still on Catalina:
These were the results for my iMac while being on the last supported OS: Catalina:
And the same test after upgrading to Monterey:
Strange to see that the single core score is lower but the important one, Multi-Core, is slightly higher so definitely not worse.
In general the system feels very snappy and I don’t really notice any performance loss in comparison with Catalina.
Hope this post will help you to extend the life of your beloved Apple Mac :)