Browsers are often an integral part of the operating system and are aware that they are virtualized. As such we would recommend finding those issues within a browser and also test with a standalone benchmark application to verify if it is a configuration issue with GPU/OpenGL usage in general or whether it is specific to that browser. It is also helpful if users verify whether the issue affects DX9, DX11 and OpenGL separately as the implementations differ.

Known Issues

• CTX202148 - Changes in Experimental Support for XenApp and Multiple GPUs
• CTX202010 - Internet Explorer is Not GPU-accelerated When Virtualized on XenServer 6.2
• CTX202065 - Mozilla Firefox Blocks GPU Acceleration for WebGL with XenApp on Windows 2012 R2/2008 R2
• CTX202066 - GPU-accelerated OpenGL on Amazon Web Services (AWS G2 instances) with NVIDIA GRID K520/K340 No Longer Works
• CTX202084 - Internet Explorer 9: Hardware Acceleration Does Not Work in Some Virtualization Environments (including vSphere/ESXi)
• CTX202106 - Publishing Chrome Browser for XenApp – so that GPU acceleration is enabled
• CTX202276 - Google Chrome Browser (Chrome 45 and upwards) Blocks GPU Acceleration with XenApp on Windows 2012 R2/2008 R2
• CTX202839 - HDX - Certain Sets of Applications (Example: Office 2013) are Not Using the GPU
• CTX204161 - Internet Explorer is Not GPU-Accelerated on XenApp for Windows Server (2012 R2 and 2008 R2)

Known Dependency for Internet Explorer: CPU must support SLAT (Second Level Address Translation)

Internet Explorer 9 and up will only be able to use a supported GPU for hardware-accelerated rendering if Service Pack 1 (for 2008 R2) is installed, and the processor supports SLAT. This is documented in the following article from Microsoft: How to enable or disable software rendering in Internet Explorer.

Most newer servers support SLAT but customers using older hardware should verify that they have SLAT support.

The following are some links that might be useful in finding the CPU SLAT support:

How to Check if Your CPU Supports Second Level Address Translation (SLAT)
Q. How can I tell if my Windows Server 2008 R2 Hyper-V implementation is using Second Level Address Translation (SLAT)?

The following are some links which might be helpful in understanding SLAT:

Second Level Address Translation
Intel virtualization (VT-x)
AMD virtualization (AMD-V)
Hyper-V: List of SLAT-Capable CPUs for Hosts
Coreinfo v3.31

Known Common Configuration Issue: Under RDP/RDS for XenApp on Windows Server Operating Systems (Win 2008 R2, Win 2012 R2 etc) are configured to disable GPU acceleration.

• On Windows Server 2008 R2, DirectX and Direct3D require no special settings to use a single GPU.
• On Windows Server 2012,Remote Desktop Services (RDS) sessions on the RD Session Host server by default use the Microsoft Basic Render Driver and therefore do not use the GPU. This prevents 2D DirectX applications (such as Microsoft Office apps) from using GPU resources for rendering which can sometimes be more efficiently performed in software. To run 3D applications that use DirectX in RDS sessions, it is recommended that they are run on a dedicated server where 2D apps are not likely to compete for GPU resources.To use the GPU in RDS sessions on Windows Server 2012, enable the "Use the hardware default graphics adapter for all Remote Desktop Services sessions" setting in the group policy.

Local Computer Policy > Computer Configuration > Administrative Templates > Windows Components > Remote Desktop Services > Remote Desktop Session Host > Remote Session Environment.


Note: There are some comments in the following Microsoft blog that fill in some details - Windows Server 2012 Remote Desktop Services (RDS)

Known Common Configuration Issue: Under RDP/RDS for XenApp on Windows Server Operating Systems (Win 2008 R2, Win 2012 R2 etc) WPF applications such as Autodesk have to be explicitly enabled

On both Windows Server 2008 R2 and Windows Server 2012 R2:
To enable WPF applications (such as Autodesks) to render using the server’s GPU, in the registry of the server running the Windows Server OS sessions, create the following settings:

Caution! Refer to the Disclaimer at the end of this article before using Registry Editor.

• [HKEY_LOCAL_MACHINE\SOFTWARE\Citrix\CtxHook\AppInit_Dlls\ Multiple Monitor Hook] ” EnableWPFHook” =dword:00000001
• [HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Citrix\CtxHook\AppInit_Dlls\ Multiple Monitor Hook] ” EnableWPFHook” =dword:00000001

The use of these registry keys is fully supported by Citrix, however customers should ensure care when editing them and Citrix will not bear responsibility for problems arising from incorrect editing of registry keys.

Known Monitoring Limitations: XenCenter Metrics show 0 for GPU-passthrough

Users should be aware of limitations in monitoring insight when using NVIDIA GRID technologies such as vGPU and GPU pass-through: Limitations in monitoring shared NVIDIA GPU technologies. GPU pass-through can only be monitored from within a guest and metrics within XenCenter or from XenServer will be shown as 0.
 

• Tools for monitoring and investigating GPU usage
  • Citrix Blog - Citrix HDX: The BIG LIST of graphical benchmarks, tools and demos!
  • Third-party list - Graphics and Multimedia System Tools
• Citrix Blog - Configuring Virtualised Autodesk and similar applications including XenApp GPU-sharing and tools for sanity checking DirectX/OpenGL usage
• Third-party blog outlining issues with various browsers and NVIDIA GRID GPU-acceleration - Citrix HDX 3D Pro and Nvidia Grid Browser experience