Making thin client performance priority No. 1

Thin client performance considerations

Thin client options that don't refresh their screens adequately will deliver a poor user experience, even if all applications are responsive and the network is clear of bottlenecks.

A good test of thin client performance is to spend a few days using a thin client as your main PC. Work on it long enough to actually feel what it's like to do your whole job with the terminal and virtual desktop infrastructure (VDI). If you find yourself wanting to go back to your PC, then other employees will probably react the same way to using a thin client.

Some thin clients are cheap because they don't have the horsepower to give a good display; the only way to know for sure is to really use one in your environment. You may be surprised to see which thin clients provide a good experience despite not being expensive and which ones have a long list of specifications and are costly but provide a poor experience as VDI clients.

It's also important to consider which remote display protocols the thin client devices support, as that's what transfers data from the virtual desktop host to the endpoint.

There are three leading remote display protocols. The baseline is Microsoft's Remote Desktop Protocol (RDP). This mature protocol is good for delivering desktops on fast local networks, but it doesn't always cope well with slower and less-reliable networks. Microsoft has added RemoteFX, which vastly improves RDP's ability to work with multimedia and 3-D displays. However, it works only with Windows thin clients and has specific hardware requirements.

Citrix offers HDX, the new name for the Independent Computing Architecture, which has been its secret sauce for more than 15 years. HDX is good at handling low-bandwidth and high-latency networks such as intercontinental WANs.

PCoIP, which Teradici Corp. developed, is licensed in VMware Horizon View. The protocol provides zero-client access to physical workstations for graphics professionals. In View, PCoIP has been developed into a software protocol for the VDI desktop, thin clients or full PC clients.

In testing, PCoIP and HDX stack up pretty similarly. The VDI product generally dictates the choice of protocol. Citrix's products use HDX and RDP, and VMware's use PCoIP and RDP. Since zero clients are usually tied to a specific protocol, the VDI product choice will limit the zero-client option. Thin clients usually support multiple protocols, making them easier to move from one VDI environment to another. Just be careful of really cheap thin clients that have limited protocol support, because that can greatly affect the overall thin client performance.

Thin client costs

Businesses have to pay for thin clients upfront, and taking $50 off the capital cost of each of 1,000 thin clients saves $50,000. This tends to be where organizations compromise and where real-world service life becomes a big consideration.

A thin client that costs 20% more to buy but will work for six years instead of four is a better deal. Most thin clients should last longer than a PC since they have no moving parts, hard disks or fans.

Thin clients, with an operating system and a conventional CPU, tend to have shorter service lives than zero clients. Zero clients often have a higher purchase price, particularly the PCoIP zero clients that have proprietary hardware rather than a commodity processor.

The lowest-cost thin clients tend to have very little flexibility or performance but are popular with call centers, where the user experience is less important than lowering cost. Remember to spread the management and support costs over the relatively long lifespan of thin clients and zero clients. Environments that conduct more frequent refreshes also need to take those costs into account.

One difficulty is quantifying the "soft" and indirect costs of the desktop device. This is the productive time lost when the device doesn't work or when users must find ways around the device's limitations to get their work done.

For example, if USB devices are disabled on the thin client and there is a need to get photos from a camera, staffers may use their smartphones and Dropbox as a workaround. Another example is a proliferation of laptops when the thin client doesn't provide a good experience. People can be very inventive in providing reasons why they need laptops when they don't like the VDI experience.

If costs include staff time for getting jobs done despite IT's efforts, it's a symptom that you are doing the wrong thing for the business.

Don't forget to check whether staffers are already using thin clients. A modern smartphone or tablet has the CPU and graphical performance of a thin client. For highly mobile staffers, you may enable the use of their phones as thin client options.

VDI vendors are releasing clients for smartphones that have support for the local touch interface, enabling mobile workers to use them as occasional access devices. In the office, these users need only a decent screen, a keyboard and a mouse that connects to the phone.

While this setup needs a lot of testing to validate usability, the idea of using a smartphone as a thin client option could save organizations from making another purchase. This could be an excellent extension to an existing enterprise mobility strategy.

It's worth mentioning that no single thin client is right for every VDI use case. Complex management will cost more in support staff time. A poor user experience could lead to resistance at rollout. An excessive purchase price will kill the project before it begins.

Whatever thin client you choose, make sure you don't compromise manageability; that is a staff cost bill that you pay every month for years. You can pick two -- a great user experience, flexibility or low cost -- but you can't have all three.