Citrix Virtual Apps and Desktops

10-Bit High Dynamic Range (HDR)

With 10-bit High Dynamic Range (HDR) virtual desktop sessions, you can use enhanced encoding and decoding capabilities to render high-quality images and videos with an extended range of colors, and greater contrast and brightness. Also, you can customize the white luminance level, Extended Display Identification Data (EDID), and visual quality to improve the user experience.

System requirements

Endpoint:

  • Citrix Workspace app for Windows 2209 or later for NVIDIA GPUs
  • NVIDIA GPUs with 10-bit HEVC (H.265) 444 decoding support on the endpoint
  • 10-bit HDR-supported monitors, 10-bit HDR must be enabled on all monitors using display settings.

Server:

  • Windows single-session OS VDA 2209 or later for NVIDIA GPUs, and VDA 2308 or later for Intel GPUs
  • NVIDIA GPUs with 10-bit HEVC 444 encoding support on the VDA

Required policies

Endpoint:

  • Enable H.265 decoding for graphics

Server:

  • Optimize for 3D Graphics workload
  • Graphics Status Indicator (optional)

Server configurations

Launching a Citrix session on a 10-bit HDR-enabled endpoint monitor enables the HDR session by default. In multi-monitor HDR sessions, all endpoint monitors must have 10-bit HDR enabled. HDR sessions are supported in both windowed and full-screen modes.

Reference White Level

This setting defines the white luminance level by nit value. It controls the relative HDR screen brightness within the session. The default value is 80 nits. Set the following registry key to define a different nit value:

  • HKEY_LOCAL_MACHINE\SOFTWARE\Citrix\Graphics
  • Type: REG_DWORD
  • Name: RefWhiteLevel

To activate the setting, you must either resize your session or disconnect and relaunch the session.

EDID override

You can configure the VDA to use the endpoint monitor EDID for your HDR sessions. This allows you to fully utilize the monitor’s display capabilities by matching the color gamut and luminance range. By default, HDR sessions assume an HDR1000-capable display. You can export endpoint monitor EDID using NVIDIA or other tools. Apply it to the VDA using the following registry key:

  • HKEY_LOCAL_MACHINE\SOFTWARE\Citrix\Graphics
  • Type: REG_BINARY
  • Name: EDIDOverride

When you store the EDID in the registry, it must not have commas, spaces, or special characters. To activate the override EDID, sign out and launch a new session.

Visual lossless experience

Enable the following policies for a visually lossless experience:

  • Allow Visual Lossless Compression
  • Visual Quality: Always Lossless or Build to Lossless

After the policies are set, you can control the HDR session quality using the Graphics Status Indicator by using the Image Quality Slider, or by switching to pixel-perfect mode.

Allow Windows screen lock

You can use this policy to allow all Windows display timeouts, including screen lock, to apply to a Citrix Virtual Desktop session on Workstation OS. This setting can be set using a Citrix Group Policy Object in Citrix Studio.

By default, when this setting is not enabled, a Citrix Virtual Desktop does not respond to timeouts for session lock, screensaver, or display off, during an active session.

When a password-protected screensaver is configured on a Workstation VDA, this setting must be enabled to allow the Citrix Virtual Desktop session to be automatically locked when the screen saver timeout is reached.

Enabling this setting when a display-off timeout is configured on the VDA causes the expiration of that timeout to result in a session that does not update until the user resumes interaction with the session. For instance, any time displayed is not updated, and new notifications are not displayed.

Other considerations

  • You can launch 10-bit HDR sessions on up to four monitors on virtual GPUs.
  • The Citrix session reverts to an 8-bit, non-HDR mode in the following instances:
    • If any endpoint monitors do not have 10-bit HDR enabled
    • Enabling screen sharing.
    • Setting a virtual display layout on the VDA.
    • Switching to pixel-perfect mode without setting the Allow Visually Lossless Compression policy.
10-Bit High Dynamic Range (HDR)