Restoring Full GPU Performance on Mac Pro 5,1 (2010) Sonoma RX 580 - Step-by-Step Guide

Guide:

Introduction: If you've successfully installed Sonoma on your Mac Pro 5,1, but are experiencing reduced GPU performance with a halved PCI link speed on your RX 580, follow this step-by-step guide to restore the full performance.

Requirements:

• macOS installation USB or recovery partition
• Basic knowledge of macOS and Hackintosh systems

Step 1: Understanding the Issue: The PCI link speed reduction may be caused by various factors, including incorrect drivers or configurations. We'll go through a series of steps to identify and fix the problem.

Step 2: Boot into macOS Recovery:

1. Insert your macOS installation USB or restart your Mac Pro while holding down the Command (⌘) + R keys to boot into macOS Recovery.
2. Alternatively, use Internet Recovery by holding down Command (⌘) + Option (⌥) + R during startup.

Step 3: Check GPU Drivers:

1. Navigate to the System Information app in macOS Recovery.
2. Go to the Graphics/Displays section and check if your RX 580 is recognized correctly.
3. Ensure that you have the latest compatible GPU drivers installed.

Step 4: Update/OpenCore Legacy Patcher (OCLP):

1. If you used OCLP for the Sonoma installation, check for any updates or patches that may address GPU-related issues.
2. Apply the latest OCLP patches and configurations for your RX 580.

Step 5: EFI/Config.plist Review:

1. Access your EFI partition using a tool like Clover Configurator.
2. Review your config.plist for any incorrect GPU-related configurations.
3. Check for compatibility with Sonoma and your specific RX 580 model.

Step 6: Verify System Integrity Protection (SIP):

1. Ensure that SIP is enabled. Disable SIP only if absolutely necessary.
2. Use Terminal in macOS Recovery to check SIP status: csrutil status.

Step 7: Reinstall macOS GPU Drivers:

1. Choose "Reinstall macOS" from the macOS Utilities menu.
2. Follow the on-screen instructions to reinstall macOS GPU drivers.
3. Check if this resolves the PCI link speed issue.

Step 8: Benchmark and Performance Tests:

1. After completing the steps, run benchmark and performance tests to ensure the GPU is operating at its full capacity.
2. Use apps like Geekbench, Cinebench, or other GPU-specific benchmarks.

Step 9: Community Support:

1. If problems persist, seek assistance from relevant Hackintosh forums or communities.
2. Share details about your Mac Pro model, Sonoma version, and GPU symptoms.

Conclusion: By following these steps, you should be able to identify and resolve the issue of reduced GPU performance and PCI link speed on your Mac Pro 5,1 running Sonoma with an RX 580. Regularly check for updates and patches that may address compatibility issues with your hardware.