Researchers at Sun Microsystems have created a new way for computer components to communicate with each other that could ultimately spell the end of the integrated circuit board.

The new technology, called proximity communication, will be presented by Sun Labs researcher Robert Drost in a paper delivered at the Institute of Electrical and Electronics Engineers' Custom Integrated Circuits Conference on Tuesday.

Proximity communication is based on the same electrical principles that govern devices that are used to store electrical charges, called capacitors. A capacitor is made up of two oppositely charged pieces of metal that are separated by an insulator material like polystyrene. They have been used in a variety of devices from radio tuners to power supplies to the Leyden jar that Benjamin Franklin used in his famous kite experiment.

Tuesday's paper will show how a team of a dozen Sun engineers, lead by Sun Fellow, Ivan Sutherland, has managed to harness the principles behind the capacitor to transfer data between chips without using the pins and wires that physically connect components in today's computers, said John Gustafson, a principal investigator with SunLabs. "You bring the chips close enough together and they can talk without touching," he said.

Using a technique called capacitive coupling, Sun engineers have been able to transfer data between components at 21.6Gbit/s - about half the speed of the 800MHz front side bus on Intel Corp.'s latest Pentium 4 microprocessor, "without even trying," Gustafson said. The rate at which data can be transferred between components like the computer's memory and processor, has increasingly become a bottleneck for the computer industry as the silicon and wires connecting computer components have simply not been able to transfer data as quickly as new components can process it.

"It's a choke point," said Gustafson. "For the longest time there was no hope in the industry of getting past that choke point."

But proximity communication could represent a workaround to this problem. Gustafson predicted that within a few years, the SunLabs team could achieve much faster transfer rates using this technique. "We could do up to a trillion bits per second, in and out of a chip, which starts to match the speed of the computer," he said.

The funding for Sun's research into proximity communication came in part from a US$50 million Defense Advanced Research Projects Agency (DARPA) grant that Sun received in July to build a prototype high-end computer system. In 2006, Sun will compete with two other companies, Cray Inc. and IBM Corp., for funding to create a fully functional system, which in Sun's case would use proximity communication.

Even if the DARPA funding does not come through, however, Sun is looking at building products that use proximity communication, Gustafson said. "The product groups want this yesterday," he said.

Gustafson believes proximity communication will make today's circuit boards "as obsolete as the vacuum tube," but that day seems far in the future, according to Richard Fichera, a research fellow with Cambridge, Massachusetts analyst firm Forrester Research Inc. "Until every piece of technology out there gets integrated with this, it's not the end of the circuit board," he said. "It's a very interesting way to connect between high-density chips."

"In three to five years, we could see this in a rollout of products from Sun, and perhaps some other selected partners, but as a de facto standard? No way," he said.

Before any products appear, however, Sun will first have to prove that it can manufacture proximity communication components in volume, something that is no easy task, according to Gustafson. "The difference between demonstrating something in the lab and making it manufacturable involves a lot of factors," he said. "We don't know, for example, what will happen if we do this on a large scale."

Still, Fichera was impressed by the discovery. "Sun isn't known as a major powerhouse of really advanced processor packaging technology," he said. "That's usually something that you associate with the big guys, so this is really an interesting leap for Sun."