Heat's on to pick sides in interconnect battle

Heat's on to pick sides in interconnect battle
Pressure is mounting in the interconnect world as HyperTransport, PCI Express, PCI-X and RapidIO backers are turning up the competitive heat, trying to win over OEMs and chip makers sweating out the question of which technologies they will or won't use.

Groups behind all four of the emerging board-level interconnects are issuing statements about new backers and staging public or private meetings to rally support. Large system makers including Cisco, Dell, EMC and Ericsson are taking increasingly vocal stands for their chosen technologies and getting attention from silicon makers hungry for design wins.

Fast interconnects are needed to link increasingly powerful processors and cards in next-generation systems. But the options have fragmented around the agendas of microprocessor makers: RapidIO will be a next-generation processor bus for PowerPCs from Motorola and probably IBM. Advanced Micro Devices is using HyperTransport as the processor bus for its K8 Hammer CPUs, and Intel developed PCI Express as a serial replacement for the ubiquitous PCI. PCI-X 2.0 was developed in large part by Compaq Computer as a stepwise upgrade of PCI for its servers.

Dell riding Express

Earlier this month, Dell invited as many as two dozen chip and board makers to a closed-door meeting to tell them it was making a strategic bet on being the first computer maker to bring PCI Express to market. According to sources who were present at the meetings, Dell executives told the chip and board makers to be ready to ship PCI Express parts to Dell by the third quarter of 2003, a goal some said was too aggressive for the technology. PCI Express is expected to be formally released as a public specification this week.

"It was clear that if you don't have PCI Express on your road map, you won't be a supplier to Dell," said one chip maker who attended the meeting and spoke on condition of anonymity.

Xilinx Inc. (San Jose, Calif.) will be the first to jump on the bandwagon, announcing Monday (July 22) that it has a soft core for PCI Express ready to go on its Virtex-II Pro FPGAs. Rival Altera Corp. (San Jose) countered that it has a PCI Express team in place and could have its own core ready within two months — if demand warrants it.

Reacting to the competition, backers of PCI-X staged their own private meeting of OEM, silicon and card backers in Saratoga, Calif., last Thursday (July 18). Proponents said they will bring to market in 2003 products using PCI-X 2.0, which is also being released as a public spec this week. Proponents see PCI-X 2.0 as an easier step forward and one they could take at least six months before PCI Express products are ready.

Meanwhile, in New Orleans this week, Motorola will announce a PowerQuicc processor with a RapidIO interface at its Smart Networks Forum. The announcement follows on the heels of news that several chip makers have joined the RapidIO Trade Association. Some of these chip makers are chasing design wins requiring RapidIO in cellular basestations being designed by Ericsson and storage-networking systems said to be in the works at EMC Corp.

Separately, a technology manager from Cisco Systems Inc. called for a compliance testing scheme for HyperTransport during last week's Platform Conference, which served as a rallying point for AMD and HyperTransport backers. "HyperTransport is probably going to be very prevalent inside Cisco," which plans to use HyperTransport processors, switches and other components in its routers, said Todd Hironaka, a manager in Cisco's technology center who also chairs a working group on HyperTransport compliance.

The combined marketing pressure from the interconnect camps is forcing system and component makers — many of which lack the resources to support all the options — to take sides in an arena where no clear winners or losers have emerged.

"All our blood and sweat is going into deciding what interconnects to back. We don't have the resources to do them all," said a senior technology manager at QuickLogic (Sunnyvale, Calif.) who asked not to be named. He said the programmable-logic maker has decided against fielding PCI-X products because of poor uptake of its 64-bit, 66-MHz PCI core, but the company is developing HyperTransport products.

Storage-networking systems maker Network Appliance, also based in Sunnyvale, is experiencing the same dynamics as QuickLogic, but is making the opposite choices.

Narrowing the options

"We need to support one of these interconnects for where our systems are going; arguably we might be able to support two," said Ko Yamamoto, director of platform development at the company. PCI-X 2.0 looks to be an easy upgrade for the company's X86/PCI-based systems next year, but beyond that, all the other candidates lack adequate speed, simplicity or reliability, he said.

Several chip makers, including Cypress, National Semiconductor, PMC-Sierra and STMicroelectronics, joined the RapidIO camp last week. PMC-Sierra was perhaps the most surprising of the new members, because the company has been very active in the HyperTransport Consortium.

Brian Holden, a principal engineer at PMC-Sierra, explained that many DSP makers are now backing RapidIO as an interconnect for DSP arrays that will be used in cellular basestations for Ericsson and in other products. That support is forcing PMC-Sierra to deliver some of its framer and mapper chips with RapidIO to compete for those design wins.

"It's not something we would prefer to do, but we have to be customer driven," Holden said.

According to two sources, storage-networking giant EMC (Hopkinton, Mass.) has put out a request-for-quote for a next-generation, front-end controller on its Symmetrix system that would use parallel RapidIO on dual-processing PowerPC cards along with serial RapidIO, in a scheme to link multiple cards in the controller box. EMC did not return calls by press time.

Mark Aaldering, director of Xilinx's IP division, said his company now has cores for PCI Express, HyperTransport and RapidIO, but has decided not to develop a core for PCI-X 2.0, because demand would be too small and limited to PC servers. Xilinx has sold nearly 2,000 site licenses for its PCI core, but "I can count on my fingers" the number of PCI-X licenses Xilinx has sold, Aaldering said.

However, Tom Cox, director of strategic planning at Tundra Semiconductor Corp. (Ottawa), said he was aware of some DSL access multiplexers and network-attached storage systems that will use PCI-X 2.0.

At the Platform Conference, HyperTransport backers clarified their road map. Version 1.05 of their spec, slated to be released this summer, will define HyperTransport switches, bring 64-bit addressing to the interconnect and provide features to better support PCI-X and PCI Express links. Version 1.1 will bring in networking extensions this fall. And HyperTransport 2.0 will define a new physical layer supporting data rates of 4 to 6 Gbits/second by early next year.

The group has so far decided not to define a coherent version of the link and to instead let members, such as AMD, go their own way on that front. While some members have discussed a serial version of HyperTransport, currently no working group is looking into it.

Fall from favor?

Meanwhile, another fast interconnect, Infiniband, continues its struggle forward, waiting for software support. Sources said Microsoft Corp. is not expected to support Infiniband in its operating systems until a future version of Windows Server.Net. And a number of companies and groups are working to pull together key management software to support Infiniband as a data center fabric.

"The big, gaping hole for Infiniband is in developing the software stack," said Mark Woithe, director of business alliances at board maker JNI Corp. (San Diego).

Many developers depicted Infiniband as a once-hot interconnect whose bloom has faded in light of the hard work involved in developing a completely new technology. Indeed, representatives of ServerWorks (Santa Clara, Calif.) pointed to the experience with Infiniband as they dismissed Dell's rallying cries for PCI Express. ServerWorks, a subsidiary of Broadcom, has said it will support PCI-X 2.0 in its PC server chip sets late this year but has no plans to back Express, despite Dell's aggressive road maps.

"We saw all the same road maps with Infiniband once and it didn't happen," said Kimball Brown, vice president of business development at ServerWorks. The company has had a chip to support Infiniband available for a year but has yet to field it for lack of demand, Brown said.