Cobalt64

Install Cobalt64

Follow each step to set up Cobalt64. It takes about 20 minutes.

Preview of the guide. The first release is not out yet, and these steps describe how it is planned to install. Today Cobalt64 also needs relaxed security settings (System Integrity Protection and AMFI), Resizable BAR, a second helper kext and a startup service; the release installer is meant to handle those. Display modes are currently fixed for the test setup, so other monitors may not light up until automatic modes land. Only ever try it on a separate macOS install.

The installation guide will be published here with the first public release.

Coming soon

Cobalt64 is not released yet. The step-by-step guide opens here as soon as the first public release ships, so you won't miss it.

In the meantime you can check whether your graphics card is supported and follow development on GitHub.

Check your GPU Follow progress on GitHub

Before you begin

Cobalt64 installs into your existing OpenCore setup. Make sure you have everything below.

Back up your EFI

Your EFI partition holds OpenCore. With a backup, you can always boot the way you do today.

  1. Open Terminal and list your disks. Find the partition named EFI on the drive you boot from, such as disk0s1.

    diskutil list

  2. Mount it, replacing disk0s1 with your partition.

    sudo diskutil mount disk0s1

  3. Copy the whole EFI folder from the mounted EFI volume to the top level of a FAT32-formatted USB drive.

If anything goes wrong later, choose the USB drive from your PC's boot menu to start up with your old setup.

Download Cobalt64

Download the latest release, then check that the file arrived intact.

Cobalt64 ·
Download

  1. In Terminal, print the file's checksum:

    shasum -a 256 ~/Downloads/Cobalt64-*.zip

  2. Unzip the download. You'll find Cobalt64.kext and Install Cobalt64.pkg.

The public release isn't out yet, but Radeon RX 9070 XT owners can install the early-access build.

Cobalt64 Early access ·
Download

Early-access builds are for testing. Keep your EFI backup handy.

  1. Unzip the download. You'll find Cobalt64.kext and Install Cobalt64.pkg.

Cobalt64 1.0 is coming soon. If you have a Radeon RX 9070 XT, you can join early access and test it before the public release.

Join early access Check your GPU

You can read through the rest of this guide now so you're ready when your build arrives.

Add Cobalt64 to OpenCore

OpenCore loads the Cobalt64 kernel extension at startup.

  1. Copy Cobalt64.kext into EFI/OC/Kexts on your EFI partition.

  2. Open EFI/OC/config.plist in ProperTree and choose File → OC Snapshot (⌘R), then select your OC folder. ProperTree adds Cobalt64 under Kernel → Add.

  3. Check that the new entry matches this, with Enabled set to true:

    <dict>
  <key>Arch</key>           <string>x86_64</string>
  <key>BundlePath</key>     <string>Cobalt64.kext</string>
  <key>Comment</key>        <string>Cobalt64 GPU driver</string>
  <key>Enabled</key>        <true/>
  <key>ExecutablePath</key> <string>Contents/MacOS/Cobalt64</string>
  <key>MaxKernel</key>      <string></string>
  <key>MinKernel</key>      <string>25.0.0</string>
  <key>PlistPath</key>      <string>Contents/Info.plist</string>
</dict>

  4. Save config.plist.

Remove conflicting settings

Cobalt64 needs to be the only driver for your Radeon. In config.plist:

  1. Under Kernel → Add, set Enabled to false for any other kext that drives the GPU, such as RDNA4FB or NootRX.

  2. Under DeviceProperties → Add, remove any entry for the GPU's PCI path that changes its device-id or model.

  3. Under NVRAM → Add → 7C436110-AB2A-4BBB-A880-FE41995C9F82 → boot-args, remove -radvesa if it's there. It turns off GPU acceleration.

  4. Save config.plist.

Install the Metal driver

Apps reach the GPU through Cobalt64's Metal driver, which lives in macOS rather than on your EFI partition.

  1. Double-click Install Cobalt64.pkg from the download.

  2. Follow the prompts and enter your administrator password when asked.

Reset NVRAM and restart

A clean NVRAM makes sure your new boot settings are used.

  1. Restart your PC.

  2. In the OpenCore boot picker, choose Reset NVRAM. If you don't see it, press Space to show more entries. It needs ResetNvramEntry.efi in your OpenCore drivers.

  3. When the PC restarts, choose your macOS drive.

The first startup can take longer than usual while macOS rebuilds its caches.

Check that it's working

Once you're at the desktop, confirm that Cobalt64 is driving your GPU.

  1. Choose Apple menu → About This Mac → More Info → System Report, then select Graphics/Displays. You should see AMD Radeon RX 9070 XT with Metal support listed.

  2. Or confirm the driver is loaded in Terminal. You should see a line containing Cobalt64.

    kmutil showloaded --list-only | grep -i cobalt64

  3. Open System Settings → Displays to arrange your displays. In early builds the resolution and refresh rate of each display are fixed.

If something goes wrong

Black screen or restart loopStart up from your USB backup using your PC's boot menu, then disable Cobalt64 in config.plist.
See what's happening during startupAdd -v to your boot-args for verbose startup.
Save the driver logThis saves a log to your desktop that you can attach to a report. 
log show --last boot --predicate 'senderImagePath CONTAINS[c] "Cobalt64"' > ~/Desktop/cobalt64-log.txt
Report a problemOpen an issue with your GPU model, macOS version and the log. Early-access testers, include your build number.

Uninstalling

Delete Cobalt64.kext from EFI/OC/Kexts, remove its entry from config.plist, then reset NVRAM and restart.

You're all set

Cobalt64 is installed. Enjoy native Radeon graphics on macOS.

Back to home

Using an early-access build? Steps may change between builds, so check the release notes that come with it.