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Sometimes, users experience issues when trying to use SLI or Crossfire configurations on Windows 11. These technologies allow multiple GPUs to work together, but they can be tricky to set up properly.

If your SLI or Crossfire setup is not working, it may be due to driver problems, compatibility issues, or simple misconfigurations. Fortunately, fixing these problems usually involves a few straightforward steps.

This guide will walk you through each step in detail, from basic checks to advanced troubleshooting. By following these instructions carefully, you can get your multi-GPU setup running smoothly again.

Let’s dive into the solutions to resolve SLI and Crossfire not working issues on Windows 11.

Quick Note: What You Should Check First

• Verify Hardware Compatibility: Ensure your GPUs support SLI (NVIDIA) or Crossfire (AMD) and that your motherboard supports multi-GPU setups.
• Use Proper Bridge or Connection: For SLI, a physical SLI bridge is usually required between GPUs. Crossfire may require bridges depending on the GPU generation.
• Latest Windows Updates: Windows 11 should be fully updated to avoid OS-related compatibility issues.
• Check Power Supply: Confirm your PSU provides enough power for multiple GPUs running together.
• Use Identical GPUs: Ideally, both GPUs should be the same model and VRAM to ensure compatibility.

Step 1: Update Graphics Drivers

Outdated or corrupted drivers are the most common cause of SLI or Crossfire not working. Updating to the latest drivers can solve many issues.

1. Visit the official NVIDIA or AMD website depending on your GPU brand.
2. Download the latest drivers for your specific GPU models and Windows 11.
3. Uninstall current GPU drivers using Device Manager or a tool like Display Driver Uninstaller (DDU) for a clean removal.
4. Restart your computer.
5. Install the freshly downloaded drivers and reboot again.

Why this is important: New drivers often fix bugs and improve multi-GPU support, ensuring better compatibility with Windows 11.

Step 2: Enable SLI or Crossfire in the Control Panel

Simply having multiple GPUs installed is not enough; you need to enable SLI or Crossfire manually.

For NVIDIA SLI:

1. Right-click on your desktop and open NVIDIA Control Panel.
2. Go to Configure SLI, Surround, PhysX under the 3D Settings section.
3. Select Enable SLI and choose the desired SLI mode.
4. Click Apply to save changes.

For AMD Crossfire:

1. Right-click on your desktop and open AMD Radeon Settings.
2. Navigate to the Gaming section and select Global Settings.
3. Find the AMD Crossfire toggle and turn it on.
4. Apply the changes.

Why this step matters: Enabling the technology in software tells your system to use both GPUs together for better performance.

Step 3: Check BIOS Settings

Sometimes, BIOS settings can interfere with proper multi-GPU functionality.

1. Restart your PC and enter BIOS/UEFI settings (usually by pressing Del, F2, or F10 during boot).
2. Look for any settings related to PCIe configurations or GPU settings.
3. Ensure that PCIe slots are enabled and set to the correct generation (e.g., PCIe 3.0 or 4.0).
4. Disable any settings that might limit multi-GPU use, such as “Above 4G Decoding” if applicable.
5. Save changes and exit BIOS.

Why BIOS settings can help: Incorrect BIOS configurations may prevent your system from detecting both GPUs properly or limit their performance.

Step 4: Verify Windows Graphics Settings

Windows 11 includes graphics settings that may impact how GPUs are utilized.

1. Open Settings > System > Display.
2. Scroll down and click on Graphics settings.
3. Check if your GPUs are listed separately.
4. For demanding apps, set the preferred GPU to High performance to make sure the system uses the multi-GPU setup effectively.

Step 5: Use Diagnostic Tools

If your SLI or Crossfire still isn’t working, you can use tools to check if both GPUs are recognized correctly.

• GPU-Z: Shows detailed info about your GPUs and whether they are connected properly.
• DXDiag: Press Win + R, type dxdiag, and check the Display tab to verify GPU details.

If one GPU is missing or disabled, it indicates hardware or driver issues that require further attention.

Alternative Method: Reinstall Windows 11

If driver updates and settings adjustments don’t work, a fresh Windows 11 install can fix corrupted system files or conflicts.

Before reinstalling, back up your important data and make sure you have installation media ready. This step should be a last resort.

Frequently Asked Questions (FAQs)

Can I use different GPU models in SLI or Crossfire?

No, SLI and Crossfire typically require identical or very similar GPUs to work correctly. Mixing different models often causes issues.

Do all games support SLI or Crossfire?

No, many modern games do not support multi-GPU configurations, so performance gains may be limited or non-existent even if your setup works.

Is an SLI bridge always necessary for NVIDIA GPUs?

Most traditional SLI setups require a physical bridge, though some newer NVIDIA GPUs support SLI without a bridge via NVLink.

Why does Windows 11 sometimes disable multi-GPU support?

Windows updates or driver conflicts can disable multi-GPU features for stability reasons. Keeping drivers and Windows updated helps prevent this.

Can I run two different brands of GPUs together?

No, SLI and Crossfire only work with NVIDIA or AMD GPUs respectively, and mixing brands is not supported.

When Nothing Works

If you have tried all the above steps and your SLI or Crossfire setup still does not work, consider the following:

• Check official forums and support: Visit NVIDIA’s or AMD’s official support pages for the latest troubleshooting guides.
• Contact manufacturer support: Your GPU or motherboard manufacturer can provide specific solutions or RMA options.
• Seek professional help: If hardware faults are suspected, a technician can diagnose issues in person.
• Consider alternative configurations: Sometimes using a single powerful GPU is more practical than troubleshooting multi-GPU setups.

Conclusion

Fixing SLI and Crossfire not working on Windows 11 involves a combination of updating drivers, enabling settings, checking BIOS configurations, and verifying Windows preferences. Starting with simple steps like driver updates and enabling SLI/Crossfire in control panels usually solves most problems.

Understanding why each step is important helps prevent future issues and ensures smoother GPU performance. When all else fails, official resources and professional support provide the next best options.

With patience and careful troubleshooting, you can enjoy the enhanced graphics power of multi-GPU setups on Windows 11.