Sun Processor Strategy SPARCs More Power

Although many acknowledge the capabilities of Sun Microsystems Inc.s UltraSPARC in high-end Solaris-based systems, they have written off the processor as antiquated and expensive.

Suns engineers, however, have come up with an UltraSPARC road map that could shake the semiconductor world. By 2005—roughly 24 months from now—Sun will announce an UltraSPARC design, targeted at blade servers, that includes the equivalent of 32 64-bit processors on the same chip. Sun officials claim this chip can do 15 times the work of todays fastest four-way servers.

Soon after, Sun officials said, systems based on the design will be 30 times faster and consume only a fraction of the power.

While the rest of the semiconductor industry was "looking right, Sun decided to go left," said Sun Software Chief Technology Officer John Fowler, in Santa Clara, Calif. "Its a new way of looking at computing."

The problem that arises with any multiprocessor system is with memory bandwidth. Although processor performance has grown exponentially, memory bandwidth has not. This is the main reason that 32-way SMP (symmetric multiprocessing) systems are so expensive and so difficult to construct.

The new UltraSPARCs will likely operate at relatively conservative frequencies (Suns current blades run at 1.015GHz), but each processor core will be able to handle multiple threads, which Sun calls Chip MultiThreading, making the processor more efficient. The future UltraSparc will actually include 8 processor cores each running four threads—the equivalent of 32 of todays typical processors.

The downside in the plans as they are now is that the new UltraSPARC will not be optimized for floating-point operations. Instead, Sun will utilize TCP offload capabilities in the processors that will make the design suitable for high-performance Web applications.

In file servers, as many as half of the processor cycles are spent managing TCP connections. Offloading those cycles should increase application performance simply because the processor does not waste time on TCP.

There are actually two generations of Suns Ultrasparcs. The first one—to be released in late 2003 or early 2004—will be dual-core systems based on the current batch of UltraSparc II and UltraSparc III pipelines. These processors will have floating point capabilities in line with the current UltarSparc processors on the market today. The dual-core processors will not have TCP offload capabilities.

A second generation of UltraSparcs, that will appear later in 2005, however, will incorporate the TCP offload technology that it received when it purchased Afara Websystems Inc. (which was itself started by a former UltraSPARC designer) last year. Its in this generation that Sun will integrate up to eight processor cores on the same chip.

The closest competitor to Sun is IBM, with its Power4, which is designed to be dual-core but optimized for floating-point operations and higher frequencies. Future Power4s will run at 2GHz, for example. The Power4 processor is also designed to be run in SMP environments, so well likely see 32-way SMP systems based on 2GHz Power4 processors in the near future.

Suns UltraSPARC designs, on the other hand, are meant for blade environments. In this regard, Sun will compete with Broadcom Corp.

Can Sun stave off the Itanium? There is no reason the Itanium cant be used in a multicore design, said Linley Gwenapp, a processor analyst at The Linley Group, in Mountain View, Calif.; however, Sun can probably fit more UltraSPARC processors on the same chip.

"Suns multicore is likely to provide better performance per watt and better performance per chip than Itanium," Gwenapp said.

Technical Director John Taschek is at john_taschek@ziffdavis.com.