NEW YORK — Firing off a long-awaited salvo in what an analyst called "an arms race" with Hewlett-Packard, IBM and Intel, Sun Microsystems Inc. rolled out the first systems based on its 64-bit Ultrasparc III microprocessor on Sept. 27. Distinguishing itself on the new 64-bit field, Sun loaded the workstations and servers with a fresh approach to multiprocessing for Internet-centric distributed computing.

Analysts generally praised the system architecture behind Sun's Net Effects workstations and servers as powerful enough to at least temporarily vault the company ahead of a highly competitive field of players angling to roll out 600-MHz+ systems.

One key to the new systems architecture is a fresh take on multiprocessing. Sun embedded a DRAM controller on its 30-million-transistor Ultrasparc III to ease contention between processors for access to memory. A switch controls the path of data over the system bus between the CPU and memory and can concentrate data flows into a wide stream at relatively high data rates.

In most multiprocessing servers, CPUs vie for access to a single bank of memory guarded by an off-chip memory controller on a system bus. In the Net Effects systems, the on-chip controller will eliminate that bottleneck and speed links to memory over an expanded 288-bit external system bus. The approach opens the door to Sun systems that will scale to handle several hundred processors in high-end configurations. Previous Sun systems topped out at 64 CPUs.

While Compaq Computer Corp. has discussed plans for placing a memory controller directly on a future Alpha microprocessor, analysts said Sun's attempt could be the first to bring such an approach into commercial computers. An on-chip DRAM controller isn't found in Sun's Ultrasparc II or, for that matter, in competing PA-RISC processors from Hewlett-Packard or Itanium processors from Intel Corp.

"Other people have looked at this approach, but this is probably the first chip actually out there in systems doing this," said analyst Linley Gwennap, principal of the Linley Group.

"The advantage of connecting the memory that way is that as you add more processors, each MPU has its own memory," Gwennap said. "Traditionally, you used one set of memory for all the processors, and the processors were bottlenecked as a result. Giving each processor its own memory opens up the bottleneck and should allow the chip to scale better into these big systems with 16 or 32 processors," he added.

Greater systems bandwidth is another aspect of the Net Effects design. The Ultrasparc III processor bus sustains data transfers at 2.4 Gbytes/second and a data-coherent system bus at the board level can handle data transfers at 9.6 Gbytes/s, a feature critical to maintaining scalability in large symmetric multiprocessing systems. The systems will also support a whopping 8 Mbytes of off-chip cache.

In addition, a new "uptime bus," separate from both system and memory buses, allows for high serviceability features. The bus is accessible at the system level and can query and diagnose the state of the processor to register errors and availability.

That feature was also in the Ultrasparc II but was a more primitive implementation and harder to access, said Ron Melanson, senior director of engineering and distinguished engineer in Sun's Microelectronics Group.

Sun's Net Effects systems are intended to compete in what Tony Massimini, an analyst with Semi Research (Scottsdale, Ariz.), called "an arms race." Now under way between Hewlett-Packard Co., IBM Corp., Intel Corp. and Sun Microsystems, the race features mega servers with symmetric multiprocessing and high bandwidth that target the high-speed, high-reliability, nonstop computing driven by the Internet.

Slight edge

By rolling out systems now, Sun has a slight time advantage over its chief competitor, Intel, which is expected to roll out its 64-bit Itanium processor and systems based on it late this year or in early 2001. Both the Sun and Intel processors have faced delays of a year or more.

"It's a gargantuan effort to develop and productize these next-generation processors," said Sun's Melanson. Sun made a "conscious effort not to push the Ultrasparc III to market, to test it really hard," he said.

The Ultrasparc III is currently running on all the new platforms at Sun because, he said, the company wanted to be sure that the processor was "100 percent debugged, 100 percent qualified."

But Sun will roll out Ultrasparc III-based systems in stages. In the last week, the company showed its first two systems based on the Net Effects architecture, the Sun Blade 1000 high-end family of workstations and Sure Fire 280R workgroup servers, targeted toward technical and service-provider markets, respectively. In three months, the company will launch new midrange products for the platform, and in six months, a high-end family rolls out.

To make up for the delay, Fadi Azari, product marketing manager for the Sparc processor group, said Sun bumped up the performance of the initial version. Instead of introducing a 600-MHz Ultrasparc III, as originally planned, the 600-MHz and 750-MHz versions of the processor will be available to ship Thursday. The Ultrasparc III will also be revved to 900 MHz by January, and a 1.5-GHz version will be introduced at the end of 2001.

The rollout Sept. 27 gives Sun a time advantage over both Intel's Itanium and IBM's Power4, analysts said. "Itanium might out-ship Sparc in the not-too-distant future, but in this business, three months or six months ahead of the game is huge," said Martin Reynolds, vice president of technology assessment at Dataquest.

Reynolds also believes that Sun is slightly ahead of the curve with the 2.4-Gbyte/s system bus, calling it "more than anything Intel has today, although Intel will catch up in a year or two."

While benchmarks for the new systems remain to be seen, Reynolds cautioned against placing too much importance on raw numbers alone. "Sun has never established itself as a performance leader, but performance is relative," he said. "Their value is more the system and the architecture. One thing Sun has in the architecture is really good bandwidth, and that's what people look for."

"I still haven't seen the performance numbers on Ultrasparc III, but I'd expect them to fall behind on Power4 benchmarks," said Gwennap. "But customers don't care about benchmarks as much as how it translates to overall performance. And customers are buying these systems for Sun's ability to deliver a good price performance.

"Ultrasparc III will make Sun more competitive," Gwennap said.

Beyond the improvements in mutliprocessing and system bandwidth, the new Sun systems are more evolutionary than revolutionary. "Ultrasparc III is the same old instruction set, but with more performance," said Reynolds. "Sun has what it needs to continue in the game, but it's not going to make everybody run off and buy Sun. It's simply executing on its technology to deliver improved performance."

Overall, analysts expect the Ultrasparc III-based systems will help Sun Microsystems maintain its strong position in the workstation and server markets. But nothing is certain, since none of the companies in this market seems to be sitting still. "Sun's always been very good at staying ahead of the curve," said Semico's Massimini, but there's "probably going to be more competition in this space as we go along."

The 600-MHz and 750-MHz versions of the Ultrasparc III will be made by Texas Instruments in a 0.18-micron CMOS process using seven layers of aluminum interconnects and the 900-MHz version will have seven-layer copper interconnects and be processed in smaller geometries. In addition to using a different metal-layer technology, the 900-MHz version has a more advanced transistor, a so-called "click" transistor that provides incremental performance improvements, Melanson said.

The next spin

Sun Microsystems executives said engineers are already working on the UltrasparcV processor and at the same time are continuing to develop the Ultrasparc II processor, evident by the recent rollout of the Ultrasparc IIe processor.

Ed Zander, Sun's chief executive, said the new Ultrasparc III and Net Effects architecture mark another one of Sun's efforts to reinvent itself, something the company has done every five years of its existence.

In 1995, Sun introduced the Ultrasparc II and symmetric multiprocessing systems that scaled to 64 processors. In 1990, Sun introduced its Ultrasparc I systems.

Zander said that the capability to enhance system performance over the network will be necessary to take advantage of the increasing thirst for bandwidth occurring worldwide as a result of the incredible Internet infrastructure buildout. He predicted that this demand will escalate over the next five years as all kinds of devices are connected to the Internet.