Citrix HDX technologies ensure that XenApp and XenDesktop users receive the most optimal user experience while using virtualized applications and desktop. Adaptive Orchestration automatically adjusts to many different access scenarios and use cases, within the boundaries and overrides set by system administrators.
Let’s take a look at the HDX graphics solutions in the new 7.11 release of XenApp and XenDesktop.
The default graphics encoding policy, “Use video codec when preferred,” has been further enhanced to use H.264 selectively, in place of JPEG, when Adaptive Display identifies a moving image. (You can find out more about this policy here). The Thinwire virtual channel for display remoting (which was significantly enhanced in XD 7.6 FP3 to handle modern Windows OS versions) is able to deliver great compatibility with legacy Receiver clients and is frugal with server and client computing resources. Also, Thinwire is capable of caching content in memory and reusing it to reduce network utilization. This is usually what our customers are looking for in most office task worker use cases.
When viewing video content, H.264 is an ideal codec choice. It was designed for video and provides excellent quality and compression. But until now, H.264 was costly in terms of server CPU consumption. So, it was used only in HDX 3D Pro mode (graphics hardware acceleration on the server) or if specially selected by the admin instead of the default policy.
Here comes the new hybrid approach.
In XenApp and XenDesktop 7.11, we redesigned the Thinwire protocol to be a hybrid engine with compatibility in mind. First, we are increasing the image quality of the Thinwire protocol when the network bandwidth is sufficient. Second, we enhanced the regional motion screen area detection of Adaptive Display with the selective encoding of motion graphics using the H.264 codec. Third, we improved cache memory utilization on server and receiver. With this new hybrid Thinwire engine, we are set to deliver a better out-of-the-box user experience for our customers and address occasional motion video graphics use cases without requiring the administrator to make a policy choice for enabling full-screen video compression via the H.264 codec.
All of this has negligible impact on server scalability for the vast majority of Citrix customers because most users don’t watch very many videos during their work week, many videos can be redirected for rendering locally on the user device, and selective H.264 only kicks in when needed. When users do watch a server-rendered video, the quality is better. And for users who need to watch server-rendered videos frequently, delivering a great video experience is important and well worth doing properly.
To take full advantage of these new enhancements in HDX, customers need to upgrade to Receiver for Windows 4.5 and Receiver for Linux 13.4.
That is the new “hybrid” Thinwire with selective H.264 for Standard Desktop VDA and Server VDA.
So, in summary:
| Standard Desktop VDA (used on servers without graphics hardware and for Remote PC Access) and Server OS VDA | Use video codec when preferred (default)
(XD7.11) For actively Changing Regions |
Do not use video codec | Use video codec when available
(XD 7.11 policy) For entire screen |
| Windows Receiver 4.5
Linux 13.4 with sufficient bandwidth |
Thinwire with selective H.264 and improved image quality | Thinwire improved image quality | Thinwire with Full-Screen H.264 |
| Windows Receiver 4.5
Linux 13.4 with limited bandwidth |
Thinwire with selective H.264 and standard image quality | Thinwire and standard image quality | Thinwire with Full-Screen H.264 |
| IOS, Mac, Android, older Windows / Linux Receiver (H.264 supported) | Thinwire with JPEG for transient regions | Thinwire with JPEG for transient regions | Thinwire with Full-Screen H.264 |
| Receiver 11.x non-H.264 supported client | Thinwire only | Thinwire only | Thinwire only |
Along with all the enhancements in Standard VDA mode, we are also enhancing the XenDesktop HDX 3D Pro VDA mode. In XenDesktop 7.11, we have introduced H.264 hardware encoding. When customers set up HDX 3D Pro Desktop VDA with a supported NVIDIA GPU detected in the virtual desktop, HDX 3D Pro will offload the CPU intensive H.264 full-screen encoding process to GPU.
Let’s take a look at how it works. When a hardware encoding supported GPU is detected in HDX 3D Pro VDA, VDA hardware encoding is turned on automatically. (This can be disabled by policy but Hardware encoding is enabled by default when a supported NVIDIA GPU is detected.) This solution can improve the user experience in graphic quality and offload the H.264 full-screen encoding process to GPU, which freeing up more resources to the application running on the HDX 3D Pro VDA and improving user experience. In the scalability testing report done by NVIDIA the improvement can increase host scalability by 30%. See NVIDIA blog for more performance details.
With all these exciting new solutions from Citrix, it is time to upgrade to the new and exciting XenDesktop 7.11 to test drive the new Hybrid!
