The server maker confirmed that Niagara taped out Tuesday, meaning the design has been sent to the fabrication plant, which will build and test prototypes.
Test chips could be available early next year, with final processors out by the end of 2005 and systems available in early 2006, consistent with Suns stated plans, analysts said.
The Niagara design, acquired along with startup Afara Websystems Inc. in 2002, incorporates a concept that Sun calls "chip multithreading," designed to vastly speed up Web content delivery by embedding eight UltraSPARC II-like cores on a single die.
Each core will support as many as four threads, allowing the chip to appear as 32 virtual processors on a single die—an approach that could prove well-suited to the thread-heavy environment of Web services, analysts said.
The chip, along with its high-end successor, "Rock," plays a central role in Suns processor roadmap after the recent cancellation of the Gemini low-end and UltraSPARC V high-end chips, industry analysts said.
"If Sun cannot demonstrate its ability to deliver superior price/performance in systems based on Niagara and Rock, then it has no business being in the processor business on a long-term basis," said analyst Nathan Brookwood, founder of Insight 64.
Gemini was seen as a competitor to lower-cost x86 chips, a gap Sun is now filling with Advanced Micro Devices Inc.s 64-bit Opteron server processor, while UltraSPARC V was seen as a stopgap between UltraSPARC V and Niagara, observers said.
Sun is planning to move UltraSPARC IV to a 90-nanometer manufacturing process with UltraSPARC IV+ next year, which should help keep existing UltraSPARC customers but is unlikely to win over new business, according to Brookwood.
That role will now fall to Niagara, which analysts said makes far more radical use of multiple cores and multithreading than comparable chips. "Intels roadmaps through 2006 mention only two cores and two threads per core, a far more constrained approach," Brookwood said.
Besides pushing forward Suns "throughput computing" agenda, the Texas Instruments-built processor will integrate four Gigabit Ethernet links, memory controller and security coprocessor, but will not include support for larger multiprocessor configurations.
"With eight cores on die and up to 32 active threads possible, the processor will probably require either large caches or huge amounts of memory bandwidth," said Kevin Krewell, editor of Microprocessor Report. He speculated that the chip probably would use DDR2 memory.
The Rock processor, next in line after Niagara, combines multithreading with virtual cores that can be dedicated to application-specific functions. But the lack of specific information on Rock has created uncertainty around Suns high-performance processor roadmap, according to a research note from Gartner Inc. last week.
Customers "should be aware that [Niagara] will not necessarily deliver similar improvements for computing-intensive loads, as envisioned for the yet-to-be-released Rock," Gartner warned.
Suns hardware competes with low-cost commodity processors from Intel and AMD, as well as with high-end alternatives such as Intel Corp.s Itanium, IBMs Power processors and Hewlett-Packard Co.s PA-RISC.