This session was presented by two non-Microsoft speakers: Benny Tritsch from AppSense and Shawn Bass from Syn-Net. After seeing their extensive testing methodology and the presentation of the results, I feel confident that the results are accurate and as neutral as one could get. The whole session was presenting the results of a battery of tests against the RDP, RemoteFX, ICA/HDX, PCoIP, EOP, Blade and RGS remoting protocols. The battery of tests included 2D graphics, video and animation, 3D graphics, LAN performance, and two WAN performance scenarios using a WAN simulator. They clearly went to great lengths to fairly test the protocols and compare the results.
One of their comments was that these remoting protocols have undergone significant changes in the last three years, and they would have not predicted the rapid advances and very good WAN performance. So for those organizations looking to implement VDI across the WAN, this is very good news. While all is not perfect for VDI WAN usage, the industry is pouring a lot of money and resources into advancing the technology.
Given the nearly all of the session was presenting video clips of all the tests, it’s really hard to summarize the results in a meaningful way. Thankfully, Microsoft has links to the audio/video recordings of the session so you can see the results for yourself. You can check out my TechEd 2011 trip report here, which has links to all of the sessions I put on my schedule. Use your browser and search on that page for VIR401.
In case you don’t want to listen to the entire 75 minute session, here’s a tiny snipit of the results:
- When using the Microsoft RDP client (mstsc), it is VERY important to select the appropriate ‘experience’ if you are using it over a WAN. Selecting the Satellite setting can greatly improve the performance over WANs by using latency ‘hints.’
- VMware View does not support any type of multi-media redirection with Windows 7. If you want MMR, look at Citrix HDX (or EOP).
- None of the protocols can redirect SilverLight or WPF content.
- Most of the protocols are very comparable on the LAN. Bandwidth utilization does very somewhat by protocol. For example, watching a SilverLight video over the LAN you can see bandwidth spikes to 45Mbps or more with RemoteFX.
- At 50ms WAN latency, you start getting a degraded user experience. Sometimes even at 20ms the experience can suffer.
- Packet loss is a huge factor in perceived WAN performance. Their tests used a .01% packet loss, which is typical of a MPLS circuit, but lower than a regular internet connection.
- Newer protocols like RemoteFX require additional hardware, be it GPUs or ASICs. Hardware assist generally does provide better results, so expect to see more hardware dependencies in the future.
- In the WAN scenarios there’s not a huge user experience difference between Citrix HDX and VMware View. In the charts shown, VMware View did use more bandwidth than HDX.
- Not all protocols support all versions of DirectX and OpenGL. So you really need to look at the applications you are using and what graphics subsystem they require. OpenGL 1.1 is pretty broadly supported. However, RemoteFX only supports 100% of OpenGL 1.1 features, and at 1.2 and higher it’s basically unsupported. On the other hand, Citrix HDX 3D supports all features through OpenGL 3.3 and much of OpenGL 4.1.
- For an optimal user experience, 2Mbps of bandwidth is best.
- If you are just using Office type applications for text manipulation, over the WAN most of the protocols do a really good job. Multi-media and graphics manipulation is where the differences really start to show up.
I’d really encourage you to watch the videos at my link above, so you can see the visual differences between the protocols. No one protocol stood out as horrible in every test, and no one protocol wiped the floor either. You need to look at the applications you want to use, performance requirements, hypervisor requirements, and other factors to make a determination on what VDI protocol you want to select.
In reality your primary choices are Microsoft RemoteFX, Citrix HDX, and VMware PCoIP. VMware View is limited to the ESX/i hypervisor, and RemoteFX is limited to Hyper-V. So that leaves HDX as the primary hypervisor independent protocol.