ThinkVirt

Disclaimer:
My testing was performed using the same underyling hardware but is not a hardcore scientific test (as I don't have the free time for that at the moment). Having said that, similar effort was made to optimize both solutions.

Disclaimer #2:
I would like to remind readers of this site that I am in pursuit of the overall greatest solution for my end clients. It's no secret that I am a fan of several big name companies in the industry. However, I also believe that competition makes products in the market mature faster and with more innovation. Today's leader could be tomorrow's follower (e.g. Microsoft) should the speed of development not keep pace with the industry.

Addendum Disclaimer #3
All components of both solutions, from brokers to virtual desktops ran on an underlying VI3.5 U4 environment managed by vCenter 2.5.

Hardware:
Dell 1950
16 GB of Memory

Storage:
HP/Lefthand VSA using local two 10k 146GB dsisk in a RAID 1 configuration

Network:
Adtran switch connecting the VI
Fortiwifi 60B connecting the clients to the VI

Clients:

Various HP, Dell, IBM laptops and desktops. Mix of IE7/8.
Latest version of Adobe Flash installed on all.

VMware View

I will say that VMware View has plenty of features that put it head and shoulders above the competition, such as:

Offline Desktop
Great for end users who will be out-of-band, the ability to check out a SECURE virtual desktop onto a local device, work off local resources while in the mountains/space/Grand Canyon and then sync only the changes when the end user is back in-band, is a fantastic feature. While marked experimental, this is working fairly well for me using WinXP as the guest OS for everything.

View Composer (Thin Provisioning from a Snapshot, with only deltas for each VM)

I'm a big fan of this feature, as it has the ability to make patching, application deployment and other administrative tasks a lot easier. Keep in mind a lot of thought needs to go into the snapshot hierarchy before implementing, or users may find themselves in a less than ideal situation. This is strategic implementation to not only conserve disk space but to also alleviate many other virtual desktop-related hassles.

• Unified Access

Another feautre I'm a fan of, Unified Access allows a VMware View broker to provide connections to View virtual desktops, physical machines, Terminal Server farms and blade PCs.

In short
For the vast majority of use cases, the recommendation may very well still be a VMware View implementation. However, I had a use case that completely revolved around Adobe Flash, and the ability to use a custom Adobe Flash-based application.

Citrix XenDesktop with HDX

Now with HDX!

Is this a fist pump of triumph or are we moments away from the user wielding a fatal blow to a poor virtual desktop solution?

Now there are several components of Citrix HDX. Let's dive deeper, as this is critical to the overall outcome:

HDX MediaStream

"HDX MediaStream leverages the processing power of the endpoint device to render the multimedia content. On the datacenter side, the compressed multimedia information is sent directly to the endpoint in its native format. The multimedia stream is rendered and played back locally, providing excellent performance while reducing the workload on the servers and the network."
Emphasis my own.

Formats supported/enhanced by Citrix HDX Mediastream

- DIVX video
- XVID video
- MPEG 4 V2 video
- MPEG1 Layer3 audio
- MPG video
- WMV video
- AC3 audio
- WMA audio
- MP3 audio

So essentially, instead of trying to process the Adobe Flash technology inside the virtual machine, HDX is offloading the work to the client device. This will be part of VMware View (speculating here) when they further their integration with Teradici and integrate the PCoverIP solution.

Another interesting note here, for those buying thin clients with minimal processing power, you may want to think twice if you plan to shove Adobe Flash at them. I've got a review coming of Clear Cube + Citrix XenDesktop vs. VMware View in the next week or so.

HDX RealTime

HDX RealTime is supported by bi-directional audio capabilities. This enables users to connect audio peripherals such as microphones and dictation hardware at the endpoint device that interact with virtual applications and virtual desktops hosted in the data center. On the server side, the real-time media stream is highly compressed and optimized to enable performance and clarity over the network.
Emphasis my own.

HDX Realtime will help those looking to support web-conferencing (for example). The audio stream is highly compressed (which likely has little result to the final quality, since these are not professional recording gear) which is a nice benefit, since network performance is often a bottleneck in virtual desktop solutions.

HDX 3D

Features listed under HDX 3D include:
- Progressive Display
- Image Acceleration

This sounds very similar to the Teradici solution in how it maximizes the end user experience through smart image delivery.

HDX Plug-n-Play

This sounds very similar to the VMware View USB redirection, which I have come to use quite often at the office. More often than not, I have an issue with the thin terminal and USB redirection, not necessarily with the VDI provider.

HDX Broadcast

This is another piece that VMware will get from Teradici: WAN optimization.

- AutoOptimizer engine
"Automates WAN optimization and adaptively tunes for optimal performance based on real-time network and traffic conditions."

- Multi-level compression
"Reduces data size up to 3500-to-1 by applying the optimal combination of multiple compression techniques."

- Instant mouse-click feedback
"When interacting with hosted applications and desktops, this feature signals the user that their click has been registered and that processing is taking place."

- Instant text-entry feedback
"When interacting with hosted applications and desktops over a high latency connection, this feature ensures that text appears on the users screen in real-time while the keystrokes are enroute to the server-–producing a seamless experience."

- Bandwidth estimator
"Dynamically adjusts ICA bandwidth consumption to meet the needs of the available bandwidth."

- Virtual channel prioritization – Enables administrators to assign a processing and communication priority to each channel within the ICA protocol.

Bandwidth and great experience for me; not so much for you.

HDX IntelliCache

- Persistent object caching
"Caches Windows® objects or bitmaps to minimize re-transmissions of those objects within the ICA session. Once objects are cached, the server merely sends a numeric identifier to the client rather than redrawing and re-transmitting the objects."

- SuperCache
"When scrolling, the client maintains regions that are no longer displayed in a local cache so that scrolling back to a previously displayed region does not require redrawing or retransmission from the server."

- Branch caching for hosted applications
"Powered by Citrix Branch Repeater, local caching and de-duplication of common display data, file and print data and media streams across multiple ICA sessions."

- Branch staging for streamed applications
"Powered by Citrix Branch Repeater, stores offline applications locally in the branch for rapid delivery and synchronizes the application whenever it is updated or patched in the datacenter."

Summary

I think this Youtube video is fairly indicative of the results I experienced in the lab. The first time I walked by a XenDesktop virtual instance playing a video on Youtube I had NO idea it was a virtual desktop. Yes, it's that good.

While VMware View arguably has plenty of other features that make it a favorite of mine for other scenarios, for Adobe Flash, at this point in time, Citrix XenDesktop with the HDX bits comes out ahead. Keep in mind that with several tweaks, VMware View is palatable as a solution for Adobe Flash. However, the HDX goodness really pushes things forward. I hope that the Teradici|VMware integration speeds along as I think that will reset where the bar lies.