Dell P2723QE 27" 4K UHD USB Type-C Hub Monitor - Manual (Page 68)

68 │ Operating your monitor
Rotate counterclockwise
90 °
NOTE: To use the Display Rotation function (Landscape versus Portrait
view) with your Dell computer, you require an updated graphics driver that
is not included with this monitor. To download the graphics driver, go to
https://www.dell.com/support and see the Download section for Video
Drivers for latest driver updates.
NOTE: When in the Portrait View Mode, you may experience performance
degradation in graphic-intensive applications (3D Gaming and etc.).