Screen Flicker On Dell Monitors When Using Third-Party Virtual Display Software

Affected Products:

• Dell Monitors

Some users may experience intermittent screen flickers on their monitor when using third-party virtual display software in macOS, such as BetterDisplay to create virtual displays at resolutions that exceed the host computers’ available memory resources. This is an industry-wide behavior that is not specific to any specific monitor brand, including Dell, and can occur with any monitor connected to a computer where the virtual display resolution exceeds the host's available memory resources.

• Intermittent or persistent screen flicker on the connected monitor
• Flicker occurs when a virtual display is configured at a resolution significantly higher than the monitor's native resolution (for example, 8K or above) using third-party software such as BetterDisplay[TN1.1] which allows the user to choose resolutions exceeding the host computers’ available memory resources
• Issue is most observed on computers with lower amounts of available video or unified memory
• Behavior may occur regardless of monitor brand or model

This behavior is caused by the host computers’ available video memory being insufficient to support the frame buffer required for the virtual display resolution configured in the third-party software. This is a host computer memory limitation and is not a defect of any monitor, regardless of manufacturer.

The likelihood of encountering this issue depends on several factors, including:

• The amount of unified memory (macOS) available
• The virtual display resolution configured in the third-party software
• The number of connected displays
• Other GPU-intensive workloads running simultaneously

Computers with higher amounts of available video or unified memory are less likely to exhibit this behavior.

To resolve the flicker, take the following steps:

1. Open the applicable third-party virtual display software
2. Reduce the virtual display resolution to a level at or below the monitor's native resolution (for example, 5K / 5120 x 2880 or below for a 4K monitor)
3. The flicker should stop immediately
4. If flicker persists, try disabling the virtual display entirely to confirm the issue is related to the third-party software
5. If flicker stops after disabling the virtual display, the issue is confirmed to be related to the third-party software and host system resources, not the monitor

• This issue is not caused by the monitor, its firmware, or its hardware, regardless of monitor brand or manufacturer
• No monitor firmware update, driver change, or hardware replacement is required to address this behavior
• The behavior is specific to third-party virtual display software that creates high-resolution frame buffers beyond the host system's available memory resources
• This is an industry-wide behavior that affects any display connected to a computer where virtual display memory demands exceed available resources
• Third-party virtual display applications acknowledge that high-resolution virtual screens are resource-intensive and may cause instability on computers with insufficient memory (users should review the application's own guidance before configuring virtual displays at elevated resolutions)
• Users who do not use third-party virtual display software are not affected
• For optimal display performance, Dell recommends using the native resolution settings supported by your computer and monitor

Need More Help?

If you continue to experience display issues after following the steps above, consider the following:

• Review the third-party software's documentation for known limitations and recommended settings
• Verify your computers available video memory or unified memory is sufficient for the desired virtual display configuration
• Ensure your operating system (macOS) is up to date
• Test with a different monitor to confirm the behaviour follows the host computer and software configuration, not the display
• Contact Dell Technical Support for further assistance with Dell monitor-related concern