OpenCore Catalina Install Guide

If you’re using NVMe storage with Big Sur as your boot drive this current version isn’t compatible with your system. You can use NVMe drives as a secondary drive or with Catalina.

What Are The Benefits?

This OpenCore Catalina install guide is perfect if you’re looking at moving straight from Mojave or High Sierra straight up to Catalina with little to no effort at all. There are a couple of tutorials out there using OpenCore but we’ve condensed all that down into a small, manageable package.

This modification also provides you with the option to navigate to the boot screen allowing you to select your startup disk without an EFI graphics card. You don’t, therefore, have to be using an original card, such as a 580, 560 or even a 5700 XT which are not usually supported on Catalina anyway. Chances are, if you are still running Mojave, you’re likely going to be running some of these cards.

Another great benefit that comes when running these EFI cards in macOS, is the fact that you’ll get hardware decoding and encoding; H.264 and H. 265. When running video editing applications such as Final Cut Pro or Premiere Pro, you will notice a considerable increase in performance, with editing generally feeling a lot smoother, render times will be reduced and there will be no need to transcode to ProRes. If you’re running a Mac for high-level video editing and you’re specifically using these cards, using this modification is a great way to unlock additional performance benefits, such as GPU acceleration from what is essentially a software upgrade.

There are also a couple of helpful byproducts of this OpenCore modification. For starters, the Thunderbolt Titan Ridge card with custom EFI will also work with this form of modification, as well as Big Sur! After downloading the Big Sur beta with our developer account, we managed to get the beta working perfectly using this exact same, blessed drive.

The first step involves mounting the EFI partition on the main drive. We would recommend removing all other drives in the system other than the drive that you wish to install on. You then want to  install a piece of software known as OpenCore Configurator and for ease we have included pre-packaged EFI files. Follow the link below and once downloaded and installed, you can go ahead and begin the first step.

Step 1

Firstly, open the OpenCore Configurator, head on up to the Toolbar and select Tools and then select Mount EFI. This will open a new window and you should see your main drive listed. Then, click Mount Partition, this will require you to enter your system’s password. Once that is complete, simply click on Open Partition which will open a new window

There will already be an EFI in there but this is just Apple’s stock EFI partition which you will need to erase. You then want to open your OpenCore drive in which we have two different configurations; one for dual-socket systems and one for single-socket. The system that we are using for this install is dual-socket so we are going to select that one. We also have two sub-folders in there, one with “Updates on” and another with “Updates off”. Once the EFI drive has been blessed in recovery mode we can utilise the “Updates off” folder but for now, we need to go with the “Updates on” in order to download and upgrade to Catalina.

We then want to drag the “Updates on” EFI folder over to our newly partitioned EFI drive and wait for that to copy across. Once that is complete, we then need to shut the system down and boot into recovery mode.

Step 2

To boot into recovery mode, power your system on and simply hold Command + R until the system enters recovery mode.

Once in recovery mode, you’ll then need to navigate to the new EFI partition and bless the drive. To do so, navigate to Utilities and then Terminal. Once in Terminal, you’ll need to find the correct partition by typing “diskutil list” which will show all of the partitions but you can ignore most of them. The EFI partition is the one we’re looking for here and it is usually located at the top of the list. You’ll then need to note down the identifier, which in our case is “disk1s1”.

You will then need to scroll back down to the bottom of Terminal and enter the following command in order to mount the partition but make sure you replace the identifier with your own unique partition identifier:

“diskutil mount /dev/disk1s1”

This partition will now be mounted. The last step in this section requires you to bless the drive. To do so, simply input the following command.

“bless –mount /Volumes/EFI –setBoot” and then hit enter.

Once this is completed, you can go ahead and close Terminal and restart your Mac. Upon restart, instead of booting straight into macOS, you’ll be presented with the boot screen loader and you’ll be able to select which drive you want to boot from, all while running a standard graphics card without any EFI.

Step 3

Once you’ve loaded back into Mojave you can navigate over to System Preferences > Software Update and let your Mac check for updates. As with any regular OS update, Catalina should appear as an option to upgrade to, as it would if you were on a natively supported Catalina Mac.

Hit “Upgrade Now” and it will begin to download the Catalina DMG Installer straight to your Applications folder. Once that’s downloaded, navigate over to your Applications folder and double click the Catalina installer, it will then begin the regular installation process, exactly the same as any other Apple software update.

Once booted back up into macOS Catalina, in order to enable GPU acceleration we need to swap the “Updates on” EFI folder with the “Updates off” folder in the hidden EFI partition. Keep in mind that this will obviously turn off updates because unfortunately, you can not have updates turned on and GPU acceleration enabled at the same time. Any time, however, you need to install updates, these two files can simply be swapped in and out to suit your needs.

To turn updates off and enable GPU acceleration, open up the OpenCore Configurator application again, navigate to Tools, Mount EFI and then Mount Partition, just the same as Step 1. Open the partition and delete the current EFI folder that is found in the hidden partition. You may want to empty the trash as this is quite a small partition and there may not be enough space. Then, simply move the “Updates off” folder over to the partition, wait for it to copy and the process is complete, following a system restart.