Risc Workstations Hold The High Ground

By John H. MayerSpecial to GCNIn the technical workstation market, performance rules. Whether you're a medical researcher, aerospace design engineer, military commander running a battle simulation or a microchip designer, you want systems that are fleet enough and powerful enough to minimize your wait for large data sets to load or for complex 3-D images to draw on-screen.Traditionally, that has required a highly optimized RISC workstation running Unix. But that presumption has come into question in recent years as machines based on Intel Corp.'s X86 processor architecture and running Microsoft Windows NT have earned a solid foothold in the high-performance workstation market.Although the market worldwide has shown excellent growth over the past year, analysts at market research firm Dataquest Inc. of San Jose, Calif., note that shipments of workstations with Intel processors running NT have grown dramatically while sales of their RISC Unix counterparts have remained relatively flat. That trend has not been lost on workstation vendors. In the past few years, Unix stalwarts such as Hewlett-Packard Co., IBM Corp. and SGI all have introduced workstations that run NT.Two factors are fanning the flames of the workstation market. First, the latest generation of Intel processors gives excellent, high-speed performance and has helped close the gap with RISC alternatives. And a new generation of systems, based on the 64-bit Merced processor under development by Hewlett-Packard and Intel and expected next year, promises to close the performance gap even further.At the same time, the lower cost of systems that run NT is an attractive lure for workstation users. Leveraging the economies of scale of the PC market, Intel workstation vendors have brought down the cost of technical workstations to a few thousand dollars.Just as important, systems running NT offer technical professionals the opportunity to run both their high-speed graphics calculations and their common office productivity applications on a single machine. No one wants to do research work on one system and then move to another to write notes.Nevertheless, if you have a compute-intensive application that demands the best in workstation performance, RISC Unix systems are still the only game in town. With their highly optimized pipelined architectures, 64-bit data paths and wide, on-chip memory caches, RISC processors continue to set the standard in processor performance.And with their state-of-the-art graphics subsystems, RISC technical workstations are still the only truly viable way to do high-end 3-D graphics and modeling. Moreover, the superior stability and scalability that Unix offers over NT likely will protect its position in the marketplace. As a result, most analysts expect RISC systems to dominate the high end of the workstation market for some time to come.The emergence of workstations running NT has had a number of positive implications for buyers of RISC systems, however. On the price front, RISC systems, under increasing pressure from low-cost Wintel machines, now sell for much less than they did just a year ago. Most vendors now offer base models for around $5,000.Vendors also are offering much more computing punch for the dollar. For instance, when Hewlett-Packard introduced three new Unix systems in May, each with twice the performance power of its predecessor, the company sold them at the same price as the earlier models.The success of the Intel boxes has helped drive Unix designers toward wider use of open industry standards. A case in point is the almost universal adoption of the PCI bus by RISC workstation vendors. That, in turn, has allowed Unix workstation users to select from a wide range of lower-cost input and output boards.The first thing to look at when selecting a RISC workstation is not necessarily the system itself but the application that will run on it.There is a widespread misconception in the workstation and PC markets that a higher CPU clock rate indicates a faster system. That is often true, but it's hardly an axiom. Performance rarely increases linearly as the CPU clock rate rises. A 20 percent increase in a CPU's clock rate is often thought to result in a 20 percent faster workstation, but in fact many other factors play into that calculation, including system memory, cache size and even disk drive support.In addition, workstation manufacturers have specialized switch-based architectures to minimize latency when system resources are shared by various subsystems. This also can have a significant impact on overall performance.Keep in mind that although the CPU clock rate may contribute to peak performance, the overall configuration of the system, including the amount of dynamic RAM, type of disk controllers and cache size, will play an important role in ultimate system performance. Moreover, performance typically is a function of how the system is used. A workstation running a database application will perform better with faster and bigger drives and more on-board RAM, while the performance of a workstation running engineering calculations will rely more heavily on the CPU clock rate.One way to sort through the marketing hype is to take a close look at leading benchmarks. Some of the widely accepted ones, such as SPEC for CPU performance, TPC for transaction-oriented applications, and PLB and X11.perf for graphics performance, can give you a feel for how a workstation will handle a specific application.Also, consulting firms such as AIM Technology Inc. of Santa Clara, Calif., offer reports on the comparable performance of workstations from leading vendors in different application environments. When technical workstations first broke into the market, they were described as any system that supported high-end graphics applications. It's easy to see why. The large majority of applications in the technical workstation marketplace, ranging from computer-aided design and scientific modeling to systems or environment simulation, demand high-performance graphics subsystems that can cope with large, complex renderings. Although the technical workstations available today are robust and well-rounded machines, the graphics subsystem still lies at the core of any product selection process.When the National Center for Atmospheric Research in Boulder, Colo., wanted to simulate thunderstorms and other weather phenomena using a weather forecasting tool, for example, it turned to AlphaServer workstations from Compaq Computer Corp. What clinched the decision was the workstation's ability to quickly calculate and draw the information required.Most RISC workstations today integrate 2-D graphics into the system, often on the motherboard itself. High-speed graphics accelerators, often with 3-D capability, are offered as standard or optional equipment on add-in boards. One thing to keep in mind is the significant memory requirements of complex graphics rendering. Many vendors tout the size of their graphics subsystem's on-board texture memory, for example. Another factor to consider is how the image will be presented. Given its graphics orientation, the display on any technical workstation is a key consideration. Most vendors offer 19- or 21-inch monitors with excellent resolution as either standard equipment or options.Don't overlook a workstation's input/output expansion options. If you plan to add extensive functionality, or even if you think you might, you'll want to select a system that gives you that opportunity.Take a close look at the number and types of I/O expansion slots each workstation offers. All systems offer additional PCI slots, but you'll need 64-bit I/O slots if you want to push graphics to the limit. Alternately, combination PCI/ISA slots let you select from a variety of lower-cost I/O add-in boards.Major RISC workstation vendors generally run their own variant of Unix on their systems. Some systems, such as the AlphaServer line, are also designed to run NT. A major trend has been the emergence of RISC workstations running Linux, the open-source version of Unix available at virtually no cost.Linux's presence in the market promises to further push down the cost of workstation computing. Compaq, one of the first vendors to offer a RISC workstation that runs Linux, expects resellers to sell the system for several thousand dollars less than workstations running Compaq's Tru64 Unix operating system. For government organizations with in-house expertise in Linux, this may present an excellent opportunity to reduce costs.