Tuesday, May 09, 2006
Chip Power Breakthrough Reported
A tiny Silicon Valley company is proposing a novel way to synchronize the operations of computer chips, addressing power-consumption problems that are a major issue facing the semiconductor industry.
Multigig Inc., a closely held start-up company in Scotts Valley, Calif., says its technology is a major advance over the clock circuitry used on many kinds of chips.
Semiconductor clocks work like the drum major in a marching band, sending out electrical pulses to keep tiny components on chips performing operations at the right time. In microprocessor chips used in computers, the frequency of those pulses -- also called clock speed -- helps determine how much computing work gets done per second.
One problem is that the energy from timing pulses flows in a one-way pattern through a chip until it is discharged, wasting most of the power. Clocks account for 50% or more of the power consumption on some chips, estimates Kenneth Pedrotti, an associate professor of electrical engineering at the University of California at Santa Cruz.
Partly for that reason, companies such as Intel Corp. have all but stopped increasing the clock speeds of microprocessors, a popular way to increase computing performance through most of the 1990s.
John Wood, a British engineer who founded Multigig in 2000, devised an approach that involves sending electrical signals around square loop structures, said Haris Basit, Multigig's chief operating officer. The regular rotation works like the tick of a conventional clock, while most of the electrical power is recycled, he said. The technology can achieve 75% power savings over conventional clocking approaches, the company says.
A typical chip would use an array of timing loops, in a grid akin to a piece of graph paper, Mr. Basit said. The loops automatically synchronize their timing pulses. That feature helps address a problem called "skew" -- the slightly different arrival times of timing pulses throughout a typical chip -- that tends to limit clock precision.
Multigig says its self-synchronizing loops can run efficiently at unusually high frequencies.
Mr. Pedrotti said past attempts to address the skew problem have tended to increase power consumption. He and his students, some of whom receive research funding from Multigig, have performed simulations that so far back up the company's claims, though the team is just about to start tests using actual chips, he said.
Multigig is in talks to license its technology to chip makers, as well as design some of its own products to use the clock technology. Besides microprocessors and other digital chips, the approach could help synchronize frequencies of communication chips, Mr. Basit said.
"This is a dramatic way of clocking circuits," said Steve Ohr, an analyst at Gartner Inc. He cautioned it could take years to get existing manufacturers to modify existing products to take advantage of the new technology. "Intel is not going to redesign the Pentium tomorrow because of it," he said.
source:http://online.wsj.com/public/article/SB114705296852946325-3BYa1bGdLzw_IHzyEATcFXEawhM_20060515.html?mod=blogs
