Latitude 9420 with Ubuntu Installed Cannot Switch the Display Mode When Connecting with Dual Qhd Monitors on a Dell Wd19 Series Docking Station
Summary: Information about display modes not switching when connected to a Dell WD19 series dock with dual QHD monitors.
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Symptoms
A Latitude 9420 with Ubuntu 20.04 that is installed cannot switch display mode intermittently when connected to dual QHD (2560x1440)@60Hz monitors on a Dell WD19 series dock.
Cause
A QHD (2560x1440)@60hz video signal uses 5.6 Gbps of bandwidth. 2 QHD video signals exceed the 8.6 Gbps of bandwidth of HBR2. Linux only supports HBR2.
Resolution
This is working as Designed, a work-around is to switch the refresh rate to 30 hz.
More information is available in the WD19 series dock user manual for Linux setting:https://dl.dell.com/topicspdf/dell-wd19-130w-dock_users-guide_en-us.pdf
Videos
Affected Products
Dell Dock WD19, Dell Performance Dock - WD19DC, Dell Performance Dock – WD19DCS, Dell Dock – WD19S, Dell Thunderbolt Dock - WD19TB, Dell Thunderbolt Dock – WD19TBS, Latitude 9420Article Properties
Article Number: 000187274
Article Type: Solution
Last Modified: 24 Apr 2025
Version: 6
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