DisplayPort over USB Type-C Adapters Not Supported on OptiPlex and Dell Precision Desktop and Rack Workstations with Specific Add-in Cards
Summary: DisplayPort (DP) over USB Type-C adapters not supported with OptiPlex desktops or Precision Workstations using Sunix USB 3.1 Type-C Add-in card or Dell Precision Thunderbolt 3 Add-in Card. ...
Symptoms
Display over USB Type-C adapters not supported with specific add-in cards
Various display issues (flicker, lost video after power cycle/S3 cycle, not able to detect) may occur on multiple OptiPlex and Dell Precision desktop and rack models if you attempt to connect a display to the Sunix USB 3.1 Type-C Add-in card or Dell Precision Thunderbolt 3 Add-in Card.
The system topology when a Sunix Add-in card or Thunderbolt 3 is installed complicates the system design. Less than favorable graphic signal strength results when a display is connected to the Sunix USB 3.1 Type-C Add-in card or Dell Precision Thunderbolt 3 Add-in Card.
Unlike mobile systems and systems with USB Type-C ports integrated into the system board, systems with an Add-in card DP loop back Type-C port do not receive DisplayPort signals directly from the graphics chipset. The result is degraded signal strength and poor graphics performance when you connect a display using a USB Type-C to DisplayPort adapter to the Add-in card port.
Note: USB Type-C and Thunderbolt 3 data operations are not affected by this limitation. Native Type-C display is not affected by this limitation.Cause
Resolution
Utilize the existing DisplayPort or mini DisplayPort connections of the system graphics adapter for video display.