Desktop Composition Redirection (DCR), H.264 Enhanced SuperCodec or Legacy Graphics Mode. Which Graphics Delivery Mode is right for you?

While working at Citrix as a Technical Relationship Manager and now at Anexinet as an Architect, I get asked a lot of questions regarding which graphics should be used in their new XenDesktop 7.x environment. My answer is, it depends! In this blog, I will give you a brief description of each Graphics Mode and when it will benefit you in your environment.

1. Desktop Composition Redirection (DCR): Allows the redirection of Desktop Composition from VDA to client to enrich user experience.

Recommended Use Cases: Main office LAN or remote home user on broadband due to high bandwidth requirement.

How to enable graphics mode: ICA\Desktop UI\ “Desktop Composition Redirection” = Enabled

2. H.264 Enhanced SuperCodec - Uses Deep Compression allowing for the delivery of server rendered video in low bandwidth connections. The codec runs completely on the server CPU and allows for a full Aero enabled desktop on any device.

Recommended Use Case – XenApp, WAN environments, mobile end points. Any endpoint which does not support DCR. Especially if accessing server rendered video or graphical content.

How to enable H.264 Enhanced SuperCodec: ICA\Desktop UI\ “Desktop Composition Redirection” = Disabled

3. Legacy Mode (XenDesktop 5.X Adaptive Display) - This setting disables the rich graphics experience and provides a fallback to the legacy graphics experience. This can improve scalability.

Recommended Use Case – WAN environments where end points cannot be updated to support H.264 and delivering Windows 7 or Server 2008 R2. If server scalability is more important than user experience with Windows 7 and Server 2008 R2.

How to enable Legacy Mode: ICA\Graphics\ “Legacy Graphics Mode” = Enabled.

Refer to the graphics policies in Citrix eDocs for configuring legacy settings.

So now that I have explained what each graphic delivery offers, below are the requirements for each.

Desktop Composition Redirection (**Note** Only available for Desktop OS VDAs)

DirectX 9 Support
Pixel Shadder 2.0 supported in hardward
32 bits per pixel
1GB RAM
128mb of video memory on the graphics card or integrated graphics processor

Since HDX queries the Windows device to verify that it has the required GPU capabilities and automatically reverts to server-side desktop composition if it does not.

H.264 Enhanced SuperCodec (**Note** For both XenApp & XenDesktop 7.x for Server OS VDA's)

Minimum Receiver Versions: Windows 3.4+, Mac 11.8+, Linux 13+, HTML5 1.3+ Latest Receiver for iOS and Android.
Increased CPU requirements on the VDA due to the H.264 processing. There is no set recommendation, so test accordingly. Depending on the intensity of the graphics, I have seen out on the field that 4CPU’s showed optimal performance.
Increased CPU requirements on the user device as well. This setting is not appropriate for Thin Clients since many have low CPU’s

Legacy Mode (XenDesktop 5.X Adaptive Display)