IBM chip aims to use light to speed up internet services By Leo Kelion

Technology reporter Published duration 10 December 2012

image caption IBM's new chip integrates optical components and electrical circuits

IBM says it has developed a chip that makes it easier to shuttle data about via pulses of light instead of using electrical signals.

The firm says it should offer a way to move large amounts of information between processors in computer servers at higher speeds than at present.

These provide computing power and data used by apps and other net services.

One third-party expert said the significance of the innovation was that it was much cheaper than other options.

Details of the development are to be presented at the International Electron Devices Meeting in San Francisco later.

Optical connections

The team behind the development said that using light, rather than the flow of electrons, to transmit data has two key advantages.

Data can be sent longer distances between different parts of a server centre without the risk of losing information.

Data transfer speeds are faster as light can be used to carry more information at once through cables.

Data centres have already started using optical cables to swap data between racks of computer chips instead of copper cables.

But at present they need special equipment to convert the light-encoded data into an electricity-based version so that the processors can make use of it.

IBM have made it possible for this conversion process to take place on a computer chip that integrates optical components side-by-side with electrical circuits on the same piece of silicon, and can be mass produced at a relatively cheap cost.

Dr Solomon Assefa, a nanophotonics scientist at IBM Research, explained why this would be useful.

image caption The chips should make it cheaper to use optical cables to connect parts of computer sever systems

"When you do an internet search your data goes into a data centre and the information wanted might not be on just one chip or even one rack of chips," he told the BBC.

"The information may be distributed across this huge data centre. The question is how to connect the chips together and do it fast. You want your results to come back to you very quickly.

"With existing technology given the amount of massive data that is flying round the network it is very difficult. With this new technology you can make this fast search happen in a way that makes economic sense."

Speedy transfers

Each chip contains a number of channels - IBM would not specify the number - that can each handle light-encoded data at speeds of up to 25 gigabits per second (Gbps).

By combining these together the firm says data can be transferred hundreds of times faster still.

IBM began producing the first chips containing the nanophotonic technology earlier this year at an existing semiconductor factory.

Dr Assefa said this was the culmination of more than a decade of research designed to help internet-based products cope with demand.

"Its driven by applications and services that continue to grow, be it search, video content, cloud computing, social networks, business analytics - all these use huge amount of data," he said.

"For our computer servers to keep up with this growth, so that we can actually make sense of the data through analytics and so forth, we need to have a new technology."

He added that IBM had yet to decide how to bring the product to market, but that it should become available to customers within "the next few years".

Breaking the bottleneck

One London-based computer expert said the development should help light-based data transmission go mainstream in server farms.

"This is not a revolution, but it is a significant evolution," commented Prof Alan Woodward, visiting professor at the University of Surrey's computing department.

image caption The innovation could mean cost savings for firms like Google which use thousands of racks of servers

"You could already do this using expensive parts but what IBM has done is said they can stamp these chips out for a much cheaper price in a factory in the same way that microprocessors are made.