Silicon Photonics

Moore's Law may shrink the distance that electrons travel between transistors, but it does little to speed their journey between chips. That bottleneck may well be broken by Luxtera Inc., a company in Carlsbad, Calif., formed by California Institute of Technology researchers who found a way to get signals in and out of chips on the backs of light waves.

Luxtera, whose name is meant to evoke the Latin words for "light" and "earth," controls costs by working in bulk silicon, using the CMOS technology into which most of the industry's capital is sunk. It has sculpted a laser, waveguide, and modulator into a tightly coupled silicon package that can be hooked up without any neurosurgical skill at all. You just snap a fiber-optic bundle into a jack.

Luxtera claims that its chip handles 10 gigabits per second and that faster speeds are in the offing. If so, broadband could become as cheap as dirt, and you'd be able to download feature-length movies in minutes.

Why, then, didn't this marvel make our winner list? Because Luxtera's got a tough competitor, Intel Corp., hot on its heels. And it remains to be seen who will come out on top.

More information at http://www.luxtera.com.

—Philip E. Ross

A Desktop Supercomputer

PHOTO: CLEARSPEED

The supercomputer industry is hotter than ever—and that's hot in the literal sense. Most high-powered systems today have hundreds or thousands of processors that drain lots of energy and dissipate enormous heat. How do you expand your machine if the computer room is full and the electric bill is going through the roof?

English chip-design firm ClearSpeed Technology PLC, in Bristol, may have a solution. It created a special coprocessor that can significantly improve a computer's number-crunching capability. The company put two of the coprocessors on a circuit board that fits the PCI-X slot available in many PCs and servers. The board sustains 50 billion floating-point operations per second (50 gigaflops) while dissipating only 25 watts. By comparison, a conventional Intel Xeon processor can sustain about a tenth of that—5 or 6 gigaflops—while generating nearly 100 watts.

What's more, you can install many ClearSpeed boards in a single computer. "Say you add four boards—that gives you 200 gigaflops," says Simon McIntosh-Smith, the company's director of architecture and applications. "Typically, you'd need a big rack of servers, and now you can have that performance on your desktop."

Some programs, like the popular Matlab and Mathematica, readily work with the ClearSpeed boards, but other applications may need to be adapted—and the tweaks may be costly and time-consuming.

ClearSpeed doesn't discuss the board's price tag, saying only that the cost will be between US $1000 and $10 000. Its technology has captured the interest of big names like IBM, Intel, AMD, and Sun, but when the boards become available early this year, will they sell?

More information at http://www.clearspeed.com.

—Erico Guizzo