Upgrading iMac Late 2013 to macOS Sonoma Using OpenCore Legacy Patcher (OCLP) – Guide and Known Issues

Since you already have macOS Ventura running smoothly on your Late 2013 iMac using OpenCore Legacy Patcher (OCLP), upgrading to macOS Sonoma is possible but does come with some potential issues. Below is a guide to help you through the process along with some known bugs and workarounds.

1. Update OpenCore Legacy Patcher (OCLP)

• Download the Latest Version of OCLP: Make sure to get the latest release of OCLP as updates often include fixes for newer macOS versions, including Sonoma.
• Reapply OCLP Patches: After updating, reapply patches to ensure compatibility with macOS Sonoma.
• Check the OCLP release notes for any specific settings or recommendations for your iMac model.

2. Upgrade macOS Ventura to Sonoma

• Backup Your Data: It’s crucial to back up your system before proceeding with a major upgrade.
• Install macOS Sonoma:
  • Use Software Update in System Settings or download macOS Sonoma from the App Store.
  • Follow the on-screen instructions to start the upgrade process.
• Reapply Post-Install Patches with OCLP: Once Sonoma is installed, boot back into OCLP and reapply any necessary post-install patches.

3. Known Issues and Workarounds on macOS Sonoma

• Wi-Fi and Bluetooth:

  • Issue: Some users report issues with Wi-Fi and Bluetooth functionality.
  • Workaround: Reapply the Wi-Fi and Bluetooth patches through OCLP after the upgrade. If issues persist, use an external Wi-Fi dongle or USB Bluetooth adapter compatible with macOS.

• Graphics Performance:

  • Issue: Certain graphics-intensive applications may show stuttering or lag, especially on unsupported or older GPUs.
  • Workaround: Ensure Metal-compatible patches are applied, as OCLP includes these for older GPUs. Lowering system animations under System Settings > Accessibility > Display can also improve performance.

• USB Ports:

  • Issue: USB ports may intermittently stop working after the upgrade.
  • Workaround: Use USBInjectAll.kext if not already installed, and verify that USB patches are applied in OCLP. Mapping USB ports with Hackintool may improve stability.

• Sleep and Wake:

  • Issue: Some users experience issues with sleep and wake functionality, where the iMac may not wake properly.
  • Workaround: Disabling sleep in System Settings > Display under Turn display off can mitigate issues. Alternatively, you can install SSDT-PM.aml in your OCLP setup, which may help resolve some sleep issues.

• Audio:

  • Issue: Audio may not work initially or may have intermittent issues.
  • Workaround: Use AppleALC.kext and ensure the correct layout-id is configured. Reapplying patches for audio through OCLP may resolve this issue as well.

4. Monitor OCLP Updates for Bug Fixes

• Since macOS Sonoma is still new, keep an eye on updates from the OCLP GitHub page as the OCLP team frequently releases fixes for issues on unsupported Macs running newer macOS versions.
• If issues are not immediately resolved, the OCLP community on GitHub or forums like Dortania can offer workarounds.

Summary

Upgrading to macOS Sonoma on your Late 2013 iMac is feasible, and many issues can be managed with workarounds or updates through OCLP. Be prepared for minor bugs, as older hardware may not support all features as smoothly as newer models. If any particular feature or application is critical for your workflow, consider waiting for additional stability improvements from OCLP updates.