Achieves both high speed and long distance; realizes high-performance large-scale servers.
Fujitsu Laboratories Ltd. and Fujitsu Laboratories of America, Inc. today announced the development of a high-speed multi-channel transceiver circuit that operates at 10 Gbps and extends in-server data-transmission distances by a factor of 1.7 over existing technology. This technology would be put to use in backplanes that serve as communication channels in multi-processor servers, which combine multiple CPUs for higher performance. The new technology can compensate for distortions in data signals that would become evident when channels are lengthened, and allows these channels to be extended from the current distance of 70 cm to 120 cm. Fujitsu’s new technology will enable the realization of large-scale high-performance server systems that can connect a great number of more processors than previously possible.
Details of the technology were presented at the IEEE International Solid-State Circuit Conference 2011 (ISSCC 2011), being held in San Francisco from February 20 – 24.
Technological Challenges:
With backplanes operating at transfer speeds of 10 Gbps, transmission losses result in signal distortions, making it impossible to transmit the data correctly. Furthermore, if the signal distortions become too large, it becomes difficult to accurately recover the clock signal components to detect either “0” or “1” data values.
These signal distortions increase with higher transmission speeds and longer transmission channels, so that in existing multichannel transceivers, the distance limit for 10 Gbps communications has been 70 cm. This makes it difficult to speed up communications in large-scale servers – which measure 85 cm wide – and pose a challenge to extending the transmission distance for high-speed transceivers.
Results:
Employing this high-speed transceiver circuitry for integrated circuits made it possible to maintain high-speed communications over longer transmission channels, paving the way for large-scale, high-performance server systems featuring more processors. Also, because this circuitry was able to reduce signal distortions to below current levels, circuit boards that were thus far made with expensive materials in order to minimize losses, could be made more inexpensively of materials that result in relatively high losses, while still achieving 10 Gbps throughput.
