IBM breaks data transfer speed record

High speed, but low range

IBM has broken the record for data transfer speeds over a multimode optical fibre, a feat which could improve performance for servers, data centres and supercomputers.

Researchers at IBM's T.J. Watson Research Centre in New York managed to send data at a speed of 64Gb/s over a 57 metre long cable. The speed is 14 per cent faster than the previous record and 2.5 times faster than commercially available technology.

The achievement was made by using custom IBM silicon-germanium chips with a vertical-cavity surface-emitting laser (VCSEL) to send the data. The laser technology was developed at Chalmers University of Technology in Sweden.

Breaking boundaries

The scientists also employed a technique known as non-return-to-zero modulation. This was previously thought to have a limit of 32Gb/s, but IBM has shown that double this is possible.

IBM researcher Dan Kuchta believes that the technology even has room for one or two further speed improvements.

He said that his team has broken a rule of thumb that posited a maximum usable data transfer rate of 1.7 times the bandwidth. This should have limited the VCSEL laser, with a bandwidth of 26GHz, to just 44Gb/s speeds, but IBM went well beyond this.

The one drawback to this success story is the limited range. At 57 metres, the technology cannot be used to improve transfer speeds across continents. However, IBM said that 80 per cent of data centre cables, and most supercomputer cables, are well within the limit.

Kuchta said the technology is now available for commercialisation.