VirtualBox on macOS: Why it's Very Slow

If you're experiencing slow performance with VirtualBox on your Mac, you're not alone. Many users have reported issues with laggy window dragging and resizing when running Linux or other operating systems within VirtualBox. In this article, we'll explore some possible causes of this problem and provide steps to help you troubleshoot the issue.

Symptoms

The slow performance is most noticeable when dragging or resizing windows within a virtual machine (VM) running on your Mac. The window may not respond immediately, taking several seconds to move or resize after you've released the mouse button. This issue has been reported by users of various desktop environments and window managers, including LXDE, XFCE, FVWM, KDE, and GNOME.

Possible Causes

There are a few potential causes for this slow performance:

* Graphics Acceleration: VirtualBox uses OpenGL to accelerate graphics rendering in 3D-accelerated VMs. However, this acceleration can sometimes cause issues on Macs with hybrid Intel/Nvidia graphics.

* Guest Additions: Installing Guest Additions, which provide additional features and drivers for the guest OS, may temporarily resolve the issue but can also cause it to reappear.

Troubleshooting Steps

To collect more information about your VirtualBox setup and diagnose the issue, you can try the following steps:

1. Enable 'Collect traces' in OpenGL Profiler: This will help you gather data about your graphics rendering performance.

2. Attach the trace to the VirtualBox process: This will allow you to capture detailed information about the VM's graphics rendering activities.

3. Close all other VirtualBox clients, including VirtualBoxManager: This will help isolate the issue and prevent conflicts with other VirtualBox components.

4. Choose a VM with enabled 3D acceleration and Guest Additions installed, then start the VM: This will help you replicate the issue in a controlled environment.

Additional Tips

If you're experiencing issues with slow performance on your Mac running VirtualBox, try the following additional tips:

* Disable graphics acceleration: If you're using 3D acceleration, try disabling it to see if this resolves the issue.

* Update your Guest Additions: Make sure your Guest Additions are up-to-date and functioning properly.

By following these troubleshooting steps and tips, you may be able to identify the cause of the slow performance in VirtualBox on your Mac and find a solution to get your VMs running smoothly again.

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