Over the past months there has been a lot of excitement around XenDesktop’s unmatchable portfolio of GPU technologies and our high-profile collaboration with NVIDIA on vGPU, sharing GPUs. However for a certain class of lightweight graphical application users, software GPU removing the need to invest in GPU hardware can be sufficient. This is where software implements optimisations for graphical libraries such as DirectX and OpenGL.

Recently I’ve been asked if we have plans for software GPU, which was a bit surprising in that we have had this feature available a rather long time!

We already have a built-in DirectX 9 software rasterizer in XD7.x in the standard VDA and we also ship an OpenGL Accelerator available for VDI-in-a-box, XenDesktop and XenApp detailed here: http://support.citrix.com/proddocs/topic/xendesktop-71/hd-opengl-accelerator.html

The OpenGL Accelerator is a software rasterizer for OpenGL applications such as ArcGIS, Google Earth, Nehe, Maya, Blender, Voxler, CAD and CAM. In some cases, the OpenGL Accelerator can eliminate the need to use graphics cards to deliver a good user experience with OpenGL applications.


Important: The OpenGL Accelerator might not work with some applications and is intended as a solution to try if the Windows OpenGL rasterizer does not provide adequate performance. If the OpenGL Accelerator works with your applications, it can be used as a way to avoid the cost of GPU hardware. It is very application specific and users do need to be aware that this type of technology can be dependent on application vendors’ implementations of the OpenGL standards and APIs.

Update: It is not necessary for users to install the OpenGL Accelerator to get OpenGL support. It is simply an additional option that may provide enhanced OpenGL support for certain applications. If your application is not one that will offer performance benefits we suggest using the default support without the Accelerator installed.

When should you try the OpenGL Accelerator?

  • If the performance of OpenGL applications running in virtual machines on XenServer or other hypervisors is an issue, try using OpenGL Accelerator. For some applications, the OpenGL Accelerator outperforms the Microsoft OpenGL software rasterizer that is included with Windows. For example, the OpenGL Accelerator supports applications using OpenGL versions up to 2.1.
  • For applications running on a workstation, first try the default version of OpenGL support provided by the workstation’s graphics adapter. If the graphics card is the latest version, in most cases it will deliver the best performance. If the graphics card is an old version or does not delivery satisfactory performance, then try the OpenGL Accelerator.
  • 3D OpenGL applications that are not adequately delivered using CPU-based software rasterization may benefit from OpenGL GPU hardware acceleration. This feature can be used on bare metal or virtual machines. For more information, see GPU acceleration for Windows Server OS.


We’ve had these technologies a while now and the possibilities opened up by the use of hardware GPUs mean that our software GPU offering now long embedded in the documentation seems to have been overlooked. For serious graphical users software GPU will be insufficient but offering the broadest and fullest range of GPU technologies on multiple hypervisors, XenDesktop gives customers the ability to mix technologies, pick and mix the most cost-effective choices for subsets of users and also retain the ability to change their hypervisor and parts of their stack to avoid vendor lock-in.