The use of two or more monitors is the norm for many business workstations, and users expect excellent performance when accessing virtual resources on these monitors, regardless of the endpoint.
Unlike a traditional desktop, users can't resolve issues with their thin client monitors and display settings on their own locally because thin clients do not host the OS. Therefore, IT administrators must deliver these resources to the end users' devices and ensure that they have the proper configuration to handle multiple monitors.
Configuring multiple monitors for a Citrix Virtual Apps and Desktops environment
There is no universal method to configure thin clients with every virtual desktop management and delivery platform. Still, Citrix Virtual Apps and Desktops (CVAD) provides a reasonable example that IT administrators can use to learn the general process for enabling multiple monitors on a thin client endpoint.
CVAD user sessions, also known as HDX sessions, present resources to users based on a series of bitmaps on the screen, and organizations often rely on thin clients to provide access to these resources at a low hardware and management cost.
When a user launches or modifies a virtual application or desktop within an HDX session, the server or cloud hosting the virtual resources modifies the bitmaps and sends the updated info to the end-user device. Whether a user is accessing these resources via a Windows, Mac, iPad, Chromebook or thin client device, the session processes are the same. However, once multiple monitors are in the mix, IT has to take administrative action to ensure users have a quality experience. Several challenges exist with multiple monitor deployments on thin clients, and IT admins will need to troubleshoot certain issues.
If any use cases require multiple monitors or extremely high resolution, IT will have to carefully review the model specifications of any thin clients the organization deploys. Many environments that benefit from thin clients, such as call centers, hot desks and general business workers, also benefit from dual monitors with about 1920x1080 resolution.
Challenges of multiple monitors on thin clients
Citrix Virtual Apps and Desktops can support up to eight monitors, but most thin client devices can only support single or dual monitors. In addition, screen resolution support varies from thin client to thin client. Thin client hardware capabilities are typically far less than full Windows or macOS devices. To address this, thin client devices can run a dedicated OS, such as Igel OS. This stripped-down OS can run as a physical device or via UD Pocket in a USB port that can support eight monitors and 4K resolution. Long gone are the days of Video Graphics Array displays.
Where dual or multiple monitors are in use, it is best for IT admins to deploy monitors based on the same size and resolution. However, this is not always possible, and issues may arise because of these discrepancies.
Troubleshooting issues with multiple monitors on thin clients
In many cases, multiple monitors will function properly by default, but issues can still arise. Problems with session presentation on multiple monitors focus on two main areas: the CVAD setup and the thin client configuration. Most often, issues will occur on the local thin client device, but the CVAD configuration may require modification.
The most common issue is that users can only see CVAD sessions on a single monitor. If an individual user reports this issue, it is most likely related to the end-user device. This may be a hardware issue or thin client configuration issue. For example, on the HP t430 thin client device, dual displays require HDMI and DisplayPort connections; a display connected via just the HDMI cannot serve as both connections for dual display.
IT admins must allocate sufficient memory for the CVAD environment, whether based on a server or workstation. This is especially important for 4K monitors. In addition, users running GPU-enabled Virtual Delivery Agents need sufficient GPU capabilities as well.
The graphics policy settings are key items within Citrix policies. In particular, the display memory limit setting may affect screen resolution for multiple monitors. The default setting is 65,536 KB, which may not be sufficient; numerous high-resolution HDX sessions require more memory than this.
HDX session presentation on a single monitor may lead to thin client configuration issues. If the thin client is not in multimonitor mode, a virtual desktop admin can remedy this with a configuration setting. For example, on Igel devices, admins can go to the window setting and ensure that the multimonitor configuration is not set to restrict full-screen sessions onto one monitor.
Where the size or resolution of the monitors differs, it is possible that the alignment of screens does not display correctly. Most users will want their CVAD session to be aligned horizontally along the top, but they may prefer center or bottom alignment. Users can adjust monitor alignment appearance on their own via the on-device display settings.
The local settings need to be adjusted if the user sees one or more screens rotated improperly -- upside down or at a 90-degree angle. Using Igel devices as an example, admins can select screen rotation on the client settings and rotate right or left.