Virtual desktop infrastructure (VDI) has brought renewed interest to alternative endpoints, especially thin clients. After all, if the desktop is running remotely as a virtual machine, why should you use an expensive, power-hungry PC to access it?
However, thin clients are far from perfect. Thin clients may be less expensive, as well as easier to and service than a PC, but those advantages are only evident when comparing a new thin client purchase against a new PC purchase. In fact, VDI offers the most bang for the buck when used with legacy PCs, eliminating the need to buy new client hardware.
Even if a client hardware refresh is on your agenda, you'll want to weigh the advantages of thin clients carefully. Most thin clients are based on technologies that were developed for terminal services solutions. They have CPUs and operating systems, and they require software installation, configuration, and maintenance. Like PCs, they must be provisioned and managed. In other words, though thin clients offer advantages over PCs, they carry some of the same baggage.
Zero client trade-offs
If you're willing to sacrifice some flexibility, you can eliminate this baggage entirely with a zero client. Unlike a thin client, a zero client has no local processing and no operating system, nor does it require software installation or configuration. It's a tiny, ultrasimple, plug-and-play device that uses very little power, never needs maintenance, and can be deployed in an instant by any end-user with enough brains to breathe.
What do you give up? At the very least, the zero client might be tied to a specific remote computing protocol or virtualization platform. For example, Wyse zero clients are available for Citrix HDX and VMware View, but not Microsoft RDP. Moreover, the zero client might be part of a completely proprietary VDI solution that limits access to virtual desktops to the vendor's own endpoint devices. This is the case with the NComputing and Pano Logic solutions, for example, neither of which makes virtual desktops available to third-party clients or via the Web (see "InfoWorld review: Desktop virtualization made easy"), nor do they work well over a WAN.
I gave the latest edition of the Pano Zero Client a spin with the recently released Pano System 4, which I deployed into a VMware View 4.5 virtual desktop environment. The device is about twice the size of a deck of cards and includes an RJ-45 10/100 Ethernet port, a DVI (Digital Visual Interface) graphics port, four USB 2.0 ports, an audio-out jack, a micro-HDMI (High-Definition Multimedia Interface), and an adapter that allows two monitor connections.
Pano System 4 gets around a number of thin client limitations. Most thin client solutions lack the ability to run multiple displays. They're also poor at multimedia applications, simply because their integrated processors lack the power to offer adequate performance to handle the additional I/O. The Pano System, on the other hand, relies on server-side processing to make those advanced features work -- giving administrators the flexibility to offer more processing power to those users who need the features.
Deploying the Pano Zero Client consists of plugging in an Ethernet cable, monitor, USB mouse and keyboard, and the included power brick -- that's pretty much it. All the real magic happens on the server side, where the rest of the Pano System is installed. The server side consists of two primary components: the Pano Manager virtual appliance, which installs on any of the three major hypervisors (VMware ESX, Microsoft Hyper-V, or Citrix XenServer), and the Pano Direct agent, a management agent that operates inside each user's virtual machine.
Installing the Pano Manager virtual appliance and provisioning virtual desktops was a snap. Pano Logic provides wizards that speed the installation, deploy the agents, and make it quite easy to associate users with virtual machines. I was also able to switch existing virtual desktops over to Pano System 4 simply by installing the Pano Direct agent on those VMs.
Everything -- dual-monitor support, USB ports, audio devices -- worked as expected, though I encountered an incompatibility with the default VMware VGA driver. A quick tech support inquiry -- and a switch to an updated video driver -- solved the problem. From a performance standpoint, the little Pano Zero Client worked well on my small test network. However, I expect larger networks with lots of traffic to impact the performance of the solution; some performance tuning may be in order for those installations.