Brightness Changes on Precision 5540 or XPS 15 7590
Summary: Learn about why the brightness changes on the screen of a Precision 5540 or an XPS 15 7950 depending on the display pattern on the screen.
Symptoms
If you have an organic light emitting diode (OLED) screen on your Precision 5540 or XPS 15 7590, you may find that the panel luminance changes based on its display pattern.
Some people perceive the symptom as the screen flickering. This can be observed whenever you are playing video games, playing back video content, or showing a Microsoft PowerPoint presentation in windowed mode.
Affected Platforms:
- Precision 5540
- XPS 15 7590
Cause
An OLED panel dynamically adjusts the screen luminance based on its on-pixel ratio (OPR) to reduce power usage. OPR represents the ratio of white pixels to the entire image.
Resolution
This is working as designed.
The panel can make the bright pixels that are displayed brighter by using the saved power from the dark pixels. This is because the panel can dynamically adjust the luminance. If the ratio of white pixels is larger, then the brightness is lower. If the ratio of white pixels is smaller, then the brightness is higher. This is called the loading effect.
The loading effect increases the peak brightness of the OLED panel with higher contrast. Dell Technologies recommends running your applications in full-screen mode or optimizing the Microsoft PowerPoint theme and content to reduce the frequency of the luminance adjustments. Using windowed mode can increase the OPR for faster changes.

Figure 1: Example with loading effect

Figure 2: Example with no loading effect