Thin clients climb back into the ring

The battle between fat PCs and thin clients is on again. Let's start with the tale of the tape:Fat PCs, which are what most people have, run a full complement of drives, peripherals and storage capability. They contain an operating system and their own applications.Thin clients lack hard drives and come with slower processors and stripped-down operating systems. Instead of storing applications, they run those supplied by a network server.A couple of years ago it looked like fat PCs had scored a technical knockout over thin clients. But thin clients are coming back, spurred by budgetary considerations.Bob O'Donnell, director of device technology research at IDC, a high-tech market research company in Framingham, Mass., said the economic downturn is forcing many organizations to slash their information technology budgets. This gives thin-client vendors an opportunity to promote the cost-benefit ratios of their products, something they haven't always been successful at.An IDC study predicts that thin-client sales could grow from this year's 1.3 million shipments to 8.7 million in 2005.Thin clients offer plenty of benefits. They are inexpensive to build and maintain. And because servers, not the clients, handle the bulk of computing tasks, thin clients don't require fast processors, huge memories or complex operating systems. In fact, their main task is to transfer user information such as keystrokes, mouse clicks and screen updates over the network to the servers.One of their main benefits is a low total cost of ownership. Because they are relatively maintenance-free, thin clients starting at about $400'without a monitor'accrue few if any additional costs over their lifetimes.In comparison, the price of a typical $1,200 PC represents only about 20 percent of its TCO. The remaining 80 percent of TCO, or about $4,800, is derived from ongoing maintenance, upgrading and repair.The thin clients included in the chart on Page 44 work somewhat like client PCs in a client-server network, but you must use slightly different criteria to evaluate them: Thin-client computing requires a multi-user operating system such as Microsoft Windows 2000 Server, Windows NT Terminal Server Edition, Unix or Linux. A stripped-down operating system such as Windows CE or a Linux kernel resides on the thin client to handle the commands to and from the server. Because the thin client doesn't generally store its own applications, the OSes can do their jobs without gobbling up much system memory. Although thin clients, by definition, provide limited interfaces, they typically come with serial, parallel, Universal Serial Bus, sound, keyboard, mouse and 10/100-Mbps Ethernet connections. USB ports are replacing legacy serial and parallel ports on most new devices. At the high end of performance and price, many new thin clients come with built-in 17-inch CRT or 15-inch flat-panel LCD screens'or, perhaps more accurately, the thin clients are built into the displays. Virtually all new units without displays can support 1,024-by-768-pixel or 1,280-by-1,024-pixel screen resolutions. Look for a device with Netscape Navigator or Microsoft Internet Explorer so that system changes can be downloaded directly from the Web.CPU. Most thin clients don't require processors running much faster than 300-MHz, and 200-MHz or 233-MHz machines are common. Again, because most processing tasks are left up to the server, thin clients can perform very adequately with 16M or 32M of fixed RAM. If you want more, some clients let you add it in increments up to 64M, 128M or 256M. Most thin client manufacturers supply their own versions of device management software used to augment the Windows, Linux or Unix OS on the server. For example, Network Computing Devices' ThinPATH software comes with its ThinSTAR thin clients and complements Win 2000 Terminal Services by enhancing key functions such as support for local peripherals. Among other features, it provides load balancing and remote control. To display Windows applications, the clients must take advantage of Citrix Systems' Independent Computing Architecture or Microsoft Corp.'s Remote Display Protocol. Depending on the application, either or both will be necessary.Citrix introduced ICA to the thin client environment with WinFrame, which brought remote display and input capabilities to NT in a version called Windows NT Terminal Server Edition 4.0. The successor to WinFrame, MetaFrame, is installed on both NT TSE and Windows 2000 with Terminal Service, and supports the display capabilities of more than 200 thin clients, including those running various versions of Unix, Mac OS or Linux.Microsoft's RDP works effectively with Windows applications but doesn't yet support as full a range of thin clients as ICA.You'll probably need a thin client with an OS such as Win CE capable of supporting both ICA and RDP. Most Windows-based thin clients have embedded terminal emulation that allows them to replace legacy dumb terminals.This guide lists three categories of thin clients.Windows-based clients, called WBTs, are designed for networks running Windows NT TSE or Win 2000. Most of them run Win CE with embedded Citrix ICA and Microsoft RDP display protocols.NT-embedded, or NTE, clients use an embedded version of NT and, like Windows-based terminals, run on NT TSE or Windows 2000 networks. Many also come with an embedded Internet Explorer browser and some embedded local NT applications. They tend to be more expensive than WBTs, but are still far less expensive to buy and maintain than PCs.Linux thin clients can connect to many Unix and Linux variants, plus NT TSE, Win 2000 Server, Sun Solaris and other OSes. They are more flexible than either WBTs or NTE devices. A drawback is that they come only with a Netscape browser, since Linux is incompatible with Internet Explorer. Check out Maxspeed Corp.'s Web site, at , for a more extensive list of thin-client types.XXXSPLITXXX-