PALM SPRINGS, Calif. — Peace is breaking out in the PC bus wars. Members of the Intel-led NGIO Forum and of the competing Future I/O group met privately at the Intel Developer Forum this week and made progress toward merging what have been two separate and contentious efforts to define a channel-based I/O architecture for tomorrow's PC servers.

"We are making progress on a number of fronts," said Tom Bradicich, director of server architecture and technology for the PC group of IBM, a backer with Compaq and Hewlett-Packard of Future I/O. "We haven't agreed on every detail and it's still possible an agreement might not happen."

In public forums here and in Monterey, Calif. in the past two weeks, both groups have been aggressively recruiting members for their approaches. But in private discussions the two are nearing an agreement on issues over intellectual property, governance and technology that currently divide them.

In particular, the big server makers in the Future I/O group have suggested the NGIO Forum may be using technologies that infringe patents based on their traditional mainframe and minicomputer businesses. While Future I/O members have sought royalties for their patents, Intel has insisted on a royalty-free scheme for NGIO.

"I think we are converging on an IP solution," said Bradicich of IBM. "I think we can agree on charging a commercially viable annual fee. We are committed that this would not be an economic burden for anyone using the architecture. But we are still looking at a couple of models for how to do that, including patent pooling."

On how the standard should be administered, both groups have already agreed on the need for an independent organization based on a one-company/one-vote rule. The NGIO Forum formally rolled out such an organization this week with a steering committee that includes members from Dell, Hitachi, Intel, NEC, Siemens and Sun Microsystems. Besides the three server companies, 3Com and Adaptec have taken part in the Future I/O effort.

'Not insurmountable'

The two groups have yet to hammer out details of how they will merge their two specs, both of which are in a draft stage. "In the technical space, we still have some disagreements, but we do not think they will be insurmountable," said Bradicich.

One of the areas of contention may be PCI-X, an extension to the PCI bus geared to allow multiple 64-bit PCI slots in a server and data transfers at speeds up to 132 MHz. The Future I/O members defined PCI-X, which is now heading toward ratification by the PCI Special Interest Group, and see it as a key stepping stone to bring end users into a new channel-based I/O architecture. NGIO backers stress the need for a break with the memory-mapped PCI bus.

"Future I/O is really a backbone for PCI buses, while NGIO is a direct-attached, channel-based I/O structure," said Balint Fleischer, director of architecture and technology for workgroup servers at Sun and an early NGIO backer.

In a keynote presentation at IDF here, Patrick Gelsinger, general manager of Intel's desktop division, said Intel will support PCI-X but that he expects it to have a short life. "We expect a role for PCI-X, but it will be narrow and transitional as we move to NGIO, which will appear in servers late in 2000 and be pervasive in servers by 2002," he said.

One PC maker in the NGIO camp said he wants to roll out systems that use both NGIO and PCI in servers that will ship late next year using the upcoming Foster version of Intel's 32-bit Pentium line. A system using only NGIO would follow a year later in servers based on the McKinley chip, part of Intel's upcoming IA-64 architecture.

For its part, the Future I/O group has said it expects systems based on PCI-X to ship late this year and the first servers to use Future I/O to ship in 2001.

A white paper from the Future I/O group notes two other areas that bring technical divergence. Future I/O uses a 1-Gbyte/second parallel copper cable, while NGIO uses a 2.5-Gbit/s serial copper interface. In addition, the NGIO specification details all the pieces of a systems-area network, while the Future I/O proposal only seeks to define switches and target devices, letting OEMs define the rest.

While the peace talks go on, both sides are working to line up more supporters, a process in which some observers said Intel currently has an edge.

"Time-to-market is key in all this, and Intel is providing a lot of collateral materials," said John Bottoms, president of Avalon Systems Inc. (Concord, Mass.), a design company that has developed routers for 3Com, Proteon and Sun and plans to join NGIO. "I've had to turn away semiconductor vendors who couldn't provide us with a reference design for their chips. We had one project we just finished up on a four-month design cycle. We don't have time to do ASICs."

Responding to those time pressures, Synopsys Inc. (Mountain View, Calif.) said this week it would work with Intel to develop a synthesizable core for target channel adapters used in the NGIO scheme. However, John Chilton, general manager of Synopsys' design reuse group, could not say when the core would be available.

"There's no schedule yet for any of these things," said Bill Ward, a senior server architect at NCR Corp., one of the few large server makers that has not yet chosen a side in the I/O war. "It looks like it may be a year before we have to make a choice. I think Future I/O is one year behind Intel's NGIO."

Significantly, major operating systems vendors have kept a neutral position in the dispute as well. Tom Phillips, group program manager for Windows 2000 at Microsoft Corp., said he has to support customers who are in both groups and was one of many voices saying the two groups need to merge or risk fragmenting the industry.