Broadcom Readies Quad ProcessorBroadcom Readies Quad Processor

An upcoming four-processor chip will give Broadcom Corp. (Nasdaq: BRCM) bragging rights in the high-end microprocessor market.

Broadcom is playing catchup to PMC-Sierra Inc. (Nasdaq: PMCS) in the market for high-end processors, chips that count routers and switches among their primary markets.
Both companies got into this market via acquisitions, with PMC buying leader Quantum Effect Devices and Broadcom picking up SiByte, the first vendor in this market to pack two cores onto one chip (see PMC-Sierra to Buy Quantum for $2.3B, Broadcom's on a Buying Spree, and Control Plane Envy).

PMC has since come up with its own dual-processor products, part of its RM9000 line. Broadcom has been preparing to up the ante, though, with a quad processor called the BCM1400. Broadcom hasn't spoken much about the chip, but it's not as if it's a secret: The company's engineers spelled out details of the BCM1400 architecture at the Microprocessor Forum roughly a year ago.

The chip was originally slated to sample in mid-2003, according to a report last year from The Linley Group. It's now set to debut early next year, with production shipments to begin after mid-2004, says Anu Sundaresan, Broadcom senior product line manager.

PMC doesn't intend to counter. "From a cost/performance point of view and a software point of view, a dual-core is going to be the sweet spot" going into the next generation of chip manufacturing, says Tom Riorden, vice president of PMC's processor division.

What could be wrong with adding more processing? One problem is the question of how to divvy up software tasks. With two cores, the answer suggests itself: One core could be dedicated to management functions, or the control and data planes could be assigned to one core each. Four cores opens up the question of splitting some tasks among processors, which makes programming more complicated.

"Trying to scale beyond two CPUs is quite complex, so we're less convinced that a quad-core CPU is the way to go," says Bob Wheeler, analyst with The Linley Group.

Naturally, Broadcom disagrees. "It is a software problem that we believe is not insurmountable," Sundaresan says. "We are already working on a number of software tools in-house to let customers take advantage of four cores."

Software aside, there's the question of the space and power it takes to add two more cores. PMC officials think it's best to wait for the next generation of semiconductor manufacturing processes, which would produce smaller, lower-power chips.

PMC's two-core processors are fabricated on 0.13-micron design rules. Another dual core is in the works for 90-nanometer (0.09 micron) level, which is the cutting edge for now. When it comes to a quad part, PMC will probably until the industry gets to 65nm (0.065µu) rules, Riorden says.

"At 65nm, we have a crossbar switch for connecting these things together, so we can just add two processors to form a quad," Riorden says, noting that the design looks "pretty reasonable" and shouldn't be difficult to implement.

In any event, it appears Broadcom will take the first shot at the quad market next year. Among the applications being targeted are high-end RAID systems as well as the usual high-end switches and routers.

— Craig Matsumoto, Senior Editor, Light Reading