Table of contents :

1: HDX System on a Chip architecture
2: SoC and Citrix Receiver
3: SoC and RemoteFX
4: SoC and Windows Embedded
5: Conclusion

1 : HDX System on a Chip (SoC) architecture

In this blog we are going to take a closer look at the SoC architecture, and I will tell you why I think this is going to change the Thinclient industry.

What is a SoC?

A system on a chip (SoC) is an integrated circuit that integrates all components of a computer or other electronic system into a single chip.

This Single Chip contains both hardware and software components. The last one is for controlling hardware components inside the SoC. Please note that the Citrix Receiver software isn’t part of this software, this software contains codecs and other controlling software bound to the SoC itself.

The following components are part of the HDX SoC :

– ARM based CPU
– DSP (Digital Signal Processor)
– DMA (Direct Memory Access)
– NIC, Audio, Video and USB Controller
– Multimedia encoders/decoders

As you can see there is a lot of stuff in the Chip, you can almost say that basically everything you need is on this Chip, only memory and storage are external from the chip. This single chip approach is also taken by many other devices such as phones and tablets.

To make the chip more visual I made a drawing of the SoC architecture, please note that this is not a diagram of how the components interact with each other, but just a basic overview of the components inside the SoC :

The DSP is an interesting one, this component is used for image decoding which would otherwise be done by the CPU. Now that the DSP is taking care of the heavy lifting, CPU cycles are saved for other processing tasks increasing performance. Because the SoC is built from industry standard building blocks, the costs are kept to a minimal, so while the performance is increasing, the costs are being lowered, that’s what I call a win-win situation 😉

2: SoC and Citrix Receiver

Citrix Receiver itself isn’t part of the SoC architecture, this has the huge advantage that the Receiver software can be modified by Citrix without the need to update the SoC, so Citrix can add more features to Citrix Receiver without being slowed down by the SoC vendors to update the SoCs. To leverage the components on the SoC, Citrix provides a modified version of the Citrix Receiver for Linux, the process that takes place is fairly simple :

1: The SoC architecture exposes API’s to the underlying OS, this is done by the SoC vendor
2: The Citrix Receiver checks if this API’s exist when booting up
3: If the API’s are in place, Citrix Receiver will use the components inside the SoC and start offloading image processing to the DSP for example.

To illustrate this, I added the Citrix Receiver into the picture :

3: SoC and RemoteFX

While Citrix started the SoC initiative with a few chip manufacturers, the SoC isn’t reserved for use with Citrix HDX only, Thinclient vendors also support other remoting protocols on Thinclients with the SoC on board, for example RemoteFX can leverage the DSP as well. Now this combination is interesting, because you might think that RemoteFX features only works on windows clients with an supported version of RDP. Since this SoC consists of an ARM CPU and is Linux based you would not expect RemoteFX features there. Well this is done through the open source RDP client named FreeRDP. FreeRDP can leverage the DSP to offload image processing as well. Please note that FreeRDP currently only supports RDP 7 in combination with Win7\2008R2, there is no support for the new Remote FX features in RDP 8 (Win8\2012) yet. There is also no official statement that Microsoft is going to support FreeRDP with the new features in RemoteFX.

4: SoC and Windows Embedded Thin Clients

The first HDX SoC is coming with an ARM based CPU, this means no support for Windows Embedded, also Citrix Receiver for Linux is the only client from Citrix that supports the SoC initially. The x86 based HDX SoC will follow later, as you might know Microsoft will release an ARM based version of Windows 8 (Windows RT). The interesting part is that there will also be a Windows Embedded 8 ARM version, this OS will be more suitable for Thinclient hardware because it’s cheaper and less power consuming. WES nowadays isn’t really made for running on cheap Thinclient hardware, it’s like a big beast in a tiny cage, it’s slow and clunky to say the least. If you are looking for a way to tame the beast you should take a look at Thinkiosk from Andrew Morgan which provides a uniform interface across all your Windows Fat and Thinclients. There is also a interesting comparison between Fat and Thinclient hardware by Kees Baggerman and Barry Schiffer which shows some interesting results and discussions.

While the Linux based SoC Thinclients has much advantages regarding performance, small footprint and costs, there are some special use cases when you need Windows on your Thinclient end-point, for example when you need local printer or scanner redirection based on Windows drivers. I don’t think you need to make the decision based solely on HDX features anymore, because the most important features are covered in both versions (Windows and Linux), but there are certainly use cases that needs Windows Thinclients, my point is don’t buy them only because there is Windows on it which sounds save, but examine the use cases and mix and match!

A little bit off topic but I summarized a few highlights of Windows Embedded 8 that looks very interesting :

– Hibernate-Once-Resume-Many restarts devices the same way every time
– Drive efficiencies by creating a custom image with only necessary functionality included
– Keyboard Filter blocks special key-combinations on both physical and virtual keyboards
– Suppress Windows system dialogs with the Dialog Filter
– Manage and configure lockdown technologies with Unified Configuration Tool
– Embedded Device Manager, together with SCCM, for operating system and application deployment

5: Conclusion

A lot of Thinclients (especially the more powerful WES variants) are almost in the same price range as a normal Fat client PC. When you are designing a VDI\SBC environment, this can be really a show stopper, because the goal on those projects is often to save money.
Now with the arrival of SoC the Thinclient is finally getting “Thin” again, Thin in form factor and price but not in performance!

5 Reasons why I think SoC Thinclients are going to take over the current Thinclient market :

1: Much cheaper to manufacture, because the SoC consist of industry standard building blocks it’s cheaper to manufacture then individual chips and components
2: The SoC uses far less energy to operate, there are even Thinclients coming that runs on PoE
3: It fits in more and smaller form factors, because it’s one chip it’s easier to integrate into other devices, such as monitors (or even TV’s)
4: The SoC is future proof, it contains standardized codecs and Citrix Receiver can be upgraded apart from the SoC
5: Performance wins, this is one of the biggest enhancements IMHO, because of the offloading and intelligent use of the SoC components performance is dramatically improved

I think with the coming of SoC we are also a step closer to nirvana phones, which I really think is the future together with BYOD.  Just dock in your phone and login, maybe Citrix should work together with some Phone manufacturers to get some HDX ready phones on the market 😉

Please note that the information in this blog is provided as is without warranty of any kind, it is a mix of own research and information from the following sources :

– Citrix unveils SoC initiative
– HDX SoC on Synergy 2012
– SoC WIKI reference
– SoC spurs innovation
– New Citrix Blog post from Vipin Borkar : Evolution of HDX SoC