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HAL Computer Systems' GP 7000F Model 400 is a departmental server that can hold up to four processors and up to 22 internally mounted disk drives. Its price starts at $16,950.

Despite improvement in server processors, servers with RISC chips maintain an for performance-dependent apps

By John H. Mayer

Special to GCN

A little over a decade ago, designers of reduced-instruction-set computing, or RISC, processors stormed into the systems arena with a radical idea. Build a processor with a simpler, more elegant architecture that would execute just one instruction per clock cycle instead of many, and you could end up with a smaller, faster CPU capable of delivering turbocharged processing.

The market jumped on the idea, and the terms RISC and high-performance computing quickly became synonymous. Systems built around processors based on traditional complex-instruction-set computing (CISC) concepts, such as Intel's X86 and Motorola's 680X0 families, were quickly relegated to low-end desktop PC applications.

But things don't stay the same for long in information technology. RISC servers still own the high end of the market and usually win all industry performance awards. But the RISC radicals who proposed their revolutionary idea just a few years ago are now looking over their own shoulders.

In the near future

Distinctions between RISC and CISC systems have evaporated as designers from each camp incorporated concepts from the other into succeeding designs. Next-generation processors, such as the Merced from Intel, promise performance on par with high-end RISC chips while retaining the application support and price-performance advantages of Microsoft Windows operating systems.

The highly anticipated Merced, due next year, not only will run Microsoft's first 64-bit OS but also has won commitments from most of the leading suppliers of RISC Unix systems. Hewlett-Packard Co., a co-developer of Merced, and Compaq Computer Corp. are developing systems using the new processor.

IBM Corp., maker of the PowerPC, will work with other vendors on a new open version of Unix for the Merced platform. Even Sun Microsystems Inc. is enabling its SunSoft Solaris OS to run on Merced. And Intel Corp.'s plans to introduce 64-bit processors for enterprise applications'the McKinley in 2001 and the Madison in 2002'are expected to keep driving processing capability skyward.

On the rise

Complicating the picture has been the rise of Microsoft Windows NT in large enterprisewide applications. Once considered unsophisticated and unreliable for large, mission-critical applications, the latest versions of NT have slowly eliminated those reservations.

Backed by its massive breadth of applications, NT has quickly picked up momentum in institutions. And at the low end, many users who haven't already moved to NT plan to make the change. For more and more IT managers, the prevailing belief is that you cannot go wrong by betting on servers with Intel chips running NT.

Numbers from market research analysts back up that view. International Data Corp. of Framingham, Mass., reported this year that sales of Unix systems declined for the second year in a row, and researchers at Dataquest Inc. of San Jose, Calif., said they expect Unix server sales to remain flat through 2002.

Vendors of RISC servers are well aware of the shifting market. Hewlett-Packard is playing a major role in the development of the Merced processor and will focus on Intel processor systems. Earlier this year SGI announced its intention to shift away from Unix systems and toward workstations and servers with Intel processors. And most other leading RISC server vendors, with the exception of Sun, are offering or planning to offer systems based on Intel chips.

SGI's Origin 2000 can hold up to eight 300-MHz R10000 or R12000 processors, with 16G of memory support and 172T of disk storage. Its price, with R12000 processors, starts at $75,804.

Despite market trends, there are still plenty of good reasons to opt for a RISC server.

One is server consolidation. Organizations looking to reduce support costs and simplify IT management find that RISC servers' ability to support more users and larger amounts of storage per system is a formidable advantage, particularly as IT managers seek to consolidate the tasks performed by multiple smaller servers into one. IT managers are quickly discovering that fewer servers mean fewer service calls, and that allows them to cut support staff or reallocate coveted resources.

Raw performance is the best reason to go with a RISC system. In general, RISC servers continue to outperform those using Intel processors, according to industry-standard benchmarks such as the Transaction Processing Council's Benchmark C. And RISC system vendors say their products will continue to outperform Merced and its successors over the next few years.

But the difference depends largely on applications. The performance advantage RISC systems have over non-RISC systems can be up to 50 percent in some applications but negligible in others, analysts said.

Compute-intensive server applications such as data warehousing, decision support or large enterprise resource planning tasks are particularly able to take advantage of the tremendous processing power RISC servers offer.

For example, Sun Microsystems, the leading vendor of Unix servers, recently announced that its top-of-the-line Enterprise 10000 servers set an industry record for the Standard Bank Customer Accounts benchmark from SAP America Inc. of Wayne, Pa. The benchmark measures processing of batch and online postings, as well as the si-multaneous display of account balances and statements. In applications such as these, a system's ability to handle a tremendously high volume of transactions at high speed from a central location is critical.

RISC servers' successes with high-end applications highlight one of the most important advantages they offer over servers with Intel chips'scalability. Most RISC system vendors offer symmetric multiprocessing systems that can be configured with 20 or more processors.

Rather than run an application on one processor, SMP systems break up the task and distribute the workload across two, four, eight or more. By sharing memory across those processors, the systems deliver billions of instructions per second of processing power while running an industry-standard OS such as Unix or NT.

Moreover, users can scale their systems simply by adding more processors, a key consideration for IT departments running data warehouse or decision support systems that quickly grow to multiterabyte size.

How big is big?

The real test for an SMP system, however, is its ability to display performance linearity as it expands from two processors to four, eight, 12 or 16. Eventually, as the user adds more processors, all SMP systems hit a wall. Data transfer between processors reaches a point that it becomes a bottleneck and performance no longer improves.

Historically, RISC servers running Unix have exhibited excellent linearity as they scale up to 20 processors and beyond. That characteristic contrasts sharply with systems running NT, which'until the most recent version of the OS came along'offered little performance improvement once a system went beyond four processors.

Despite the attention paid to the capabilities of individual RISC processors, experts recommend that IT managers in the market for a server take a close look at a server's system architecture and its applicability to specific applications.

SMP system developers typically rely heavily on high-speed system buses, specialized input/output architectures, and extensive memory caches to keep data moving across a multiprocessor system.

Many RISC servers use a traditional system design built around a very high-performance bus to accommodate the massive CPU-to-memory traffic generated by shared-memory SMP architectures.

Others use a crossbar switch or some other specialized interconnect to help speed data throughput.

Tips for buyers

' Identify your specific application needs in processing throughput, disk storage and long-term scalability.

' Look for a balanced system architecture that can avoid the system bottlenecks your application is most likely to encounter.

' Research the developer's plans to continue to evolve its microprocessor architecture.

' Look closely at how many processors a system will support and how linear system performance improves as more processors are added.

' Make sure you purchase just enough disk storage'the most expensive component in any server'to meet your needs.

Generally, the larger the capacity of the system bus, the less likely a server will encounter system bottlenecks as the processors in the system pass increasingly larger amounts of data back and forth.

Another important consideration in selecting a RISC server is its data storage and I/O bandwidth capabilities. Typically, mass storage is the most expensive part of a server. So it is critical that you buy a configuration that meets your needs but does not exceed them to avoid wasting critical resources.

Although some low-end RISC servers support only a limited amount of disk storage internal to the system, most accommodate multiterabytes of disk arrays external to the system.

Battering RAM

Nevertheless, it is important that the overall system architecture is capable of supporting that mass-storage configuration. Applications for high-end data warehousing and decision support, for example, typically bring together massive amounts of data and require substantial disk or tape storage.

In those applications the ability to move data off a disk and into the processors can easily overshadow raw processor speed. Usually, these types of applications require an extremely high number of simultaneous disk accesses and the I/O bandwidth to support them.

Tadpole-RDI's Voyager IIi has a 360-MHz UltraSparc IIi processor, 1G of RAM and 32G of internal disk storage. Its price starts at $11,995.

Specifications such as maximum I/O bandwidth and the ability to support large amounts of disk storage may play a more important role in your system selection than the type or number of processors supported.

The ability to handle large amounts of RAM is also critical. Systems with large memory configurations let users place entire applications of large portions of databases into physical memory and minimize disk I/O. Once limited to relatively small memory configurations, Unix systems today can support many gigabytes of RAM.

Vendors and independent analysts offer a variety of benchmarks to help you measure the performance of one server against another, but the best place to start is with a few key questions: What will the system be used for? How many will use it? Is the application going to be disk- or calculation-intensive? How fast will the application requirements grow?

The best system for you will not be the one with the fastest processor or largest disk capacity but the system with the right configuration for your needs.

John H. Mayer writes about information technology from Belmont, Mass.

Vendor Product Processor, maximum number, clock rate Memory support Disk storage Comments Price
Bull Information Systems Inc.
Billerica, Mass.

EPC 400 EPC 800 PowerPC 604e, four, 360 MHz 3G 109G internal Entry-level application server, supports AIX 4.3 $28,000
EPC 800 PowerPC 604e, eight, 262 MHz 4G 73G internal General purpose server, supports AIX 4.3 $45,000
EPC 1200 PowerPC RS64 I, 12, 262 MHz 32G 437G internal Large database server, supports AIX 4.3 $130,000
Compaq Computer Corp.
Alphaserver ES40 21264, four, 500 MHz 16G 15T external, 1T Supports Tru64 Unix, OpenVMS, NT, Linux; has 10 64-bit PCI slots $23,900
Alphaserver 4100 21164, four, 600 MHz 8G internal 15T Midrange server; supports Tru64 Unix, OpenVMS, NT $77,922
Alphaserver GS60E 21264, six, 525 MHz 12G 85T Supports Tru64 Unix, OpenVMS, NT $85,000
Alphaserver GS140 21264, 14, 525 MHz 28G 85T Supports Tru64 Unix, OpenVMS, NT $399,400
Hewlett-Packard Co.
Palo Alto, Calif. 800-752-0900
K-Class PA-8200, six, 240 MHz 8G 30T Supports HP-UX 11.0, has 960- megabyte/sec processor bus $79,900
N-Class PA-8500, eight, 440 MHz 16G 71T Supports HP-UX 11.0, has 12 I/O slots $48,000
HAL Computer Systems Inc.
Campbell, Calif.
GP7000F Model 200 Sparc64, two 275 MHz 4G 18.2G internal Entry-level server, supports Solaris 64-bit architecture; also in rack- mountable version, Model 200R $8,500
GP7000F Model 400 Sparc64, four, 296 MHz 8G 60T external Departmental server, supports Solaris 2.6 also in rackmountable version, Model 400R $16, 950
GP7000F Model 600 Sparc64, eight, 275 MHz 8G 90G internal Midrange server, supports Solaris 2.6 $36,900
IBM Corp.
Armonk, N.Y.
AS/400e Model 170 PowerPC AS16, two, CPW rating 3.5G 175G Entry-level server $11,176
AS/400e Model 720 PowerPC AS35, four, CPW rating 16G 1.2T Departmental server $36,530
RS/6000 S80 PowerPC RS64, 24, 450 MHz 64G 45T High-end server, supports AIX Version 4.3.3, has 14 PCI slots $290,000
Siemens Information
and Communications
Products LLC
San Jose, Calif.
RM300 E70 R12000, two, 285 MHz 2G 72G internal Entry-level server, supports Reliant $28,000
RM400 E70 R12000, four, 285 MHz 8G 216G internal Departmental server, supports Reliant Unix 5.44 $34,000
RM600 E80 R12000, 24, 285 MHz 24G 846G internal High-end server, supports Reliant Unix 5.45 $165,000
Mountain View, Calif.
Origin 200 R10000 or R12000, four, 270 MHz 8G 20T Has cc:NUMA architecture, six hot-plug drive bays, three 32/64-bit PCI slots $17,659 with R12000
SGI 2100 R10000 or R12000, eight, 250 MHz 8G 16G 20T 172T Has cc:NUMA architecture, three PCI slots; supports Irix 6.5 $33,000
Origin 2000 R10000 or 16G R12000, eight, 300 MHz 172T Has cc:NUMA architecture, supports Irix 6.5 $75,804 with R12000
Sun Microsystems Inc.
Palo Alto, Calif.
3500 UltraSparc, eight, 400 MHz 8G 2T Supports Solaris 2.5.1, has SyMon management software and Gigaplane system interconnect $11,000
4500 UltraSparc, 14, 400 MHz 14G 4T Supports Solaris 2.5.1, has SyMon management software and Gigaplane system interconnect $32,000
5500 UltraSparc, 14, 400 MHz 14G 6T Supports Solaris 2.5.1, has SyMon management software and Gigaplane system interconnect $43,000
6500 UltraSparc, 30, 400 MHz 30G 10T Supports Solaris 2.5.1, has SyMon management software for enterprise applications $120,000
Tadpole-RDI Inc.
Carlsbad, Calif.
Voyager IIi UltraSparc Iii, one, 360 MHz 1G 32G internal Notebook size, supports Solaris 7 $11,995

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