Menlo Park, Calif. -- Andy Bechtolsheim likes to call them fat nodes--dense servers stuffed with ever more off-the-shelf silicon to maximize performance per dollar, per watt and per square meter. Venerable computer companies like IBM and Hewlett-Packard are vying to define such a box, which could become the building block for tomorrow's data centers and one of the more profitable products for the margin-squeezed computer industry.

Sun Microsystems Inc. will take unique spins on the concept this week with the introduction of three systems defined by Bechtolsheim, a veteran designer and Sun's co-founder. The systems embody the struggling company's campaign to push the industry beyond today's mainstream, two-processor designs to adopt servers packing four or more CPUs, while leveraging the new PCI Express Module specification for adapter cards.

It's doubtful four-way and larger systems will go mainstream anytime soon, and it's uncertain whether the PCI Express Module will gain sufficient traction to become a standard. What is clear from Sun's pending announcement is that the industry is increasingly consolidating around the X86--and headed deep into territory where mechanical design, particularly in power and cooling, will help determine winners and losers.

All three the new systems from Sun (Santa Clara, Calif.) are based on Advanced Micro Devices' Opteron processor. The Sun Blade 8000 packs four high-end Opterons on each of 10 blades in a chassis that consumes almost half a standard rack. That compares with IBM and HP systems that typically put only two Intel Xeon CPUs on each blade but pack 14 to 16 blades in a chassis one-fifth or one-sixth the standard rack size.

While not as physically dense in raw CPUs as competing systems from IBM and HP, the Blade 8000 marks a credible return to the server blade market for Sun, after a three-year hiatus and a well-thought-out use of the Opteron's capabilities.

Sun wants to push the envelope further. Bechtolsheim revealed he is working to shrink the Sun Blade so the company can stack three chassis, rather than two, in a standard rack.

The new SunFire X4600, meanwhile, is one of the first eight-way AMD systems from a top-tier computer maker, holding up to eight Opterons in a 4U-sized box. And the novel X4500 is a two-processor data server that packages 48 drives with up to 24 terabytes of data in a 4U system.

P>The current rise of software that virtualizes computer resources is expected to spur users to buy fewer but denser systems for their data centers. "This is a consolidation play, and consolidation will come on bigger machines," said Bechtolsheim.

Sun is betting on an uptick in so-called scale-up computing, leveraging the integrated nature of the Opteron to nudge the industry to four- and eight-processor systems. Such systems will push Sun's X86 designs deeper into what was traditionally the realm of RISC-based systems such as HP's Itanium, IBM's Power and Sun's own Sparc CPUs.

"The time is ripe to make bigger boxes. The industry is stuck at two sockets, and we will move that up," said Bechtolsheim. "It's preferable to have fewer boxes, and that means more sockets per box."

Sun snagged a proof-of-concept for its opinion in June when the Tokyo Institute of Technology landed on the Top 500 supercomputer list at number 7, using a cluster of the eight-way SunFire 4600 systems. The group specifically asked for "fat nodes" to create a cluster that would be easier to manage than a network with many more two-socket systems.

Bechtolsheim predicted that Intel and AMD will compete more fiercely in the four-way-and-up sector going forward, rolling out more chips at lower prices for scale-up systems. But, so far, that hasn't been the trend.

AMD initially priced its four- and eight-way-capable Opterons at about $3,000 each, at parity with Intel's high-end Xeons. Later, AMD cut prices to about $1,500 for the chips. But with the shift to dual-core Opterons, AMD is again pricing the high-end parts at about $3,000.

Nevertheless, AMD's high-end processors cost less to make than Intel's, and systems built with them incur less cost too, said Nathan Brookwood, principal of market watcher Insight64 (Saratoga, Calif.).

Brookwood noted that a four-way, dual-core Opteron system can be built today on an eight-layer circuit board. Intel will not have a dual-core chip for four-way systems using its new Core CPU architecture until late next year, and the systems probably will require a 12-layer or thicker board, he said. That prospect may have been a factor in Dell's recent announcement that it will use Opteron for four-way systems.

Just a microtrend
Analysts and competitors said Sun may see benefits from an uptick in four-way systems as users adopt virtualization software, but they believe the shift will be modest and two-way servers will remain dominant.

"We think there is a better story for larger systems now and in the future because of virtualization software, but we don't expect four-way to become the leading volume part of the market," said Paul McGuckin, an analyst with Gartner Dataquest.

In the past few years, two-way servers have commanded nearly 75 percent of the total number of servers shipped each year, while four-way systems have accounted for as little as 4 percent and eight-ways less than 1 percent, said Gartner researcher Jeffrey Hewitt. With the move to virtualization, four-ways are likely to rise to 10 percent of the market by 2009, nudging toward 1 million systems a year. Eight-ways, however, are unlikely to hit much more than about 40,000 systems a year during the period, Hewitt said.

Doug Balog, vice president of server blades at IBM, likewise said that "all the data we see suggests the two-way blade will remain the sweet spot."

With four-core processors arriving from both Intel and AMD within a year, single-CPU designs could gain new interest, Balog said. "Anything beyond four-way typically degrades in performance due to multiple hops fetching memory on one processor to feed another one. It's not the most optimal design."

In the early 1990s, Intel acquired Corollary Inc., a maker of eight-way X86 chip sets, as the industry dabbled with scale-up designs. But the parts proved expensive and complex, and the industry shifted to so-called scale- out designs, based on clusters of cheaper, one- and two-CPU servers linked with Gbit Ethernet and Infiniband. Sun will be hard-pressed to buck that trend.

Search giant Google is seen as the poster child for scale-out computing based on globally distributed clusters of as many as 150,000 single- and dual-processor X86 servers. The company has crafted proprietary hardware and software for system interconnect, which it claims is the biggest bottleneck in its data centers today.It has kept the nature of its work secret, however.

"The cost of a connection point dwarfs the cost of the computer. That's a big problem," Alan Eustace, a vice president of engineering and research at Google, said in an interview earlier this year.

Standard I/O
Separately, Sun's new 8000 systems are the first to bet big on the PCI Express Module as a standard for networking adapters in the data center. NEC and Taiwanese ODMs have demonstrated systems using Express modules, but with the 8000 launch Sun became the first company to use them in a major product.

Six card makers--including Emulex and QLogic--announced a total of seven Express modules in tandem with Sun's launch. Another half-dozen companies in Taiwan are said to be prototyping modules, and companies such as Intel are promoting the designs to end users.

"You will see this adopted by other systems vendors because it's a super I/O design," said Sun's Bechtolsheim. "We will develop other products [using the modules] in the future."

By contrast, IBM and HP have been using their own designs for I/O cards, forcing third parties to tailor cards for their server blade chassis.

"One of the big drawback of blades has been how proprietary their adapters are," said Gartner's McGuckin. "But Sun by itself can't set an industry standard here."

Even if Sun fails to nudge the industry toward four-way systems and Express modules, however, it will have taken the X86 into fresh territory. What's more, the three new systems, while novel, did not require a single ASIC.

"We are showing you can build this class of system with off-the-shelf components," said David Lawler, a director of product definition and strategy who worked with Bechtolsheim on the systems. "It's a matter of aligning the work of processor and disk makers and moving forward."

Computer design has shifted away from silicon, Lawler said. "Power, cooling and management are where the challenges are, now that so much has become standardized," he said.

That's not to say the work has become simple. Bechtolsheim said the brunt of the architectural design of the products came out of a single meeting almost two years ago. But it took months of mechanical design, airflow simulation, integration and software testing to get the complex products ready for market.

"The hardest thing is cooling. We designed this machine for the highest-performing CPUs, and that creates heat issues," said Bechtolsheim. Sun prototyped an eight-way blade for the 8000, but the chassis could not handle today's top-end CPUs, let alone the four- and eight-core versions on the AMD road map, he said.

"I think there will be 140-W CPUs in this chassis next year," said Bechtolsheim. "In reality, CPU power is going up. It is only going down on a per-core basis. The total power per chip is going the other way."

Brighter than Sparc?
Some observers said the high-end X86 systems suggest the sun may soon set on the Sparc CPU. "This could make it easier for Sun to diminish investment in Sparc, keeping it focused on the very high end or for its installed base. They could even transition over to Opteron over the next five to 10 years," said Gartner's McGuckin.

Indeed, sales of RISC-based systems declined from 6.3 million units in 2002 to 4.6 million in 2005, although sales of Sun's Sparc servers gained some ground over the period, according to Gartner. "The Opteron business has been one of the bright spots for Sun over the last couple years, when they have not had much good news," McGuckin said.

Sun clearly continues to invest in Sparc. It recently launched Web servers based on its Niagara CPU. Bechtolsheim said the 8000 will use Niagara2 blades when that chip is ready. And the company has a new high-end CPU, Rock, in an early design phase.

Nevertheless, the company is trying to slash costs in search of profits that have eluded it since the dot-com crash. In May, Sun announced plans to lay off about 12 percent of its work force, or about 4,500 people, in an effort to slice roughly $500 million a year in costs.