March 16, 2008 9:00 PM PDT

IBM opens processor communications with optical switch

Posted by Michael Kanellos

IBM has devised an optical switch that it says could one day allow processor cores to exchange large files rapidly, the company plans to announce Monday.

The component, which is still in the experimental stage, is the latest piece of technology in the field of optoelecronics. Currently, signals inside chips gets passed on electrons running on microscopic wires. Compared with photons (particles of light), electrons are slow, and they generate heat. In optoelectronics, researchers hope to take technology from fiber-optic communication and shrink it to the chip level. Ideally, these miniaturized components can be produced inexpensively on silicon, increase computing performance, and reduce power consumption. IBM estimates that a chip connected with optical technology rather than wires would use a tenth of the power and 100 times more data could be shuttled between the cores per second than with today's chips.

The switch essentially directs data traffic between cores. The component can handle multiple wavelengths of light and has a potential aggregate bandwidth of one terabit per second, far more than what conventional input-output communication systems between chips can do today. Greater bandwidth would reduce latency between cores. It is also small enough to fit inside computers: 2,000 of them could fit into a square millimeter.

IBM also ran tests in harsh, high-temperature environments that simulate the inside of a functioning computer and it continued to work.

A number of companies--IBM, Intel, and start-ups like Primarion--have been experimenting with silicon lasers, waveguides, and other components for making optoelectronics a reality for about eight years. One of the coolest is a device that IBM came up with to slow down light to make it easier to encode with data. These components, however, won't show up in computers for at least a few more years.