Slimming TCO With Thin Clients

ENT, March 4, 1998 by David B. Miller

NetPCs, NCs and Windows terminals all promise to reduce the fat of cost of ownership. So what does this diet require in terms of servers, networking tools and system software?

Thin client vendors promise a computing revolution with radical reductions in total cost of ownership and increased productivity at performance levels similar to or better than users enjoy now.

"We anticipate that very few changes will need to be made to an existing environment and that managers and users alike will be very happy with the performance level of thin clients," says Bruce Knaack, manager of the performance group of IBM Corp.'s Network Computer Division.

Any revolution, however, requires careful strategic planning. Knaack urges caution. "Network and system administrators alike need to tackle the thin client issue as they would any other proposed significant change in their environment. We recommend modeling performance characteristics by conducting a pilot study of five systems or so before proceeding too far down the road."

Got Milk?

Implementers of thin client technology face several choices and a considering introducing thin clients into their environments would do well to learn the differences, not only from a cost perspective, but also from the perspective of how each thin client model affects their server farms and backbones.

Thinking of thin clients as one thinks of milk might help.

The traditional PC makes up the whole milk category. You've got it all with the "fat PC": milk, cream, great taste, the works. Fat PCs run applications locally, with server access being limited to client database requests, network printing, and file saving and retrieving.

The 2 percent fat variety is the domain of the now not-so-popular NetPC, pioneered by Microsoft Corp. and Intel Corp. Essentially a centrally managed PC, the NetPC runs applications stored locally, on its own hard disk drive, downloading software only when a version update is required. Performance characteristics of this class of thin client would closely follow that of the traditional PC.

Network computers (NC) comprise the 1 percent fat milk category. Based on Java and following the Network Computer Reference Model, as defined and pioneered by Sun Microsystems Inc., Oracle Corp. and IBM, NC technology enables applets to be downloaded to the NC for execution. The idea is to make the Java applets more efficient and lean, providing just what the user needs at the time rather than forcing the client to download the typical multimegabit application. Locally caching the applets removes the load of executing them from the server. Without permanent storage, however, the applets need to be downloaded across the network at every reboot.

The skim milk arena belongs to Windows terminals. Windows terminals rely solely on server-based applications. Users of X Window System terminals will find the Windows terminal model to be quite familiar. A very small operating system runs on the Windows terminal to allow it to connect to a Windows NT server, which is running multiuser code such as Microsoft's Windows Terminal Server (formerly code-named Hydra) running the T.Share protocol, or Citrix WinFrame running the Independent Computing Architecture (ICA-3) protocol. Processing occurs and data resides on the server, while the client concentrates on graphics and display functions.

Many of us grew up on whole milk. We probably grimaced a little when we tried all the other varieties. Vendors of thin clients have a large task. Whether manufacturers of the 2 percent NetPC or the skim milk Windows terminal, they need to produce a product that users, system administrators and network managers alike will drink. One of the best ways to make thin clients palatable is to meet or exceed the performance levels to which users of traditional PCs have grown accustomed.

There is room and a need for various client types. Vendors such as IBM and Neoware (King of Prussia, Pa.) offer clients that go both ways, providing access to multiuser Windows NT applications while providing the benefits of Java. "One of the misconceptions about thin clients is that they are `anti-Microsoft,' or `anti-PC,"' says Michael Kantrowitz, executive vice president of Neoware, one of the earliest providers of thin clients. "While it is true that the original Java NC was designed as a competitor to the PC, the products that people are actually buying in volume are what we call `universal thin clients,' machines that run Windows applications on a central server, and also include terminal emulation, UNIX connectivity, a Web browser, e-mail and Java. These thin clients offer an alternative to the PC that is easier to use and administer, and they're mostly installed in environments alongside PCs."

No matter what category of thin client, commonalties emerge as to server, client, network and application performance that administrators should consider before embarking into thin client territory.

Rambo Servers?

Are you champing at the bit to get your gigahertz, eight-way Pentium II mega-powerhouse? Don't rely on thin clients to realize your dream. Well, not totally, at least.