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Original URL: http://www.theregister.co.uk/2010/02/17/nec_usb_speed_boost_tech/

NEC works out how to triple USB 3.0 speed

16Gb/s data transfers, anyone?

By Tony Smith

Posted in Hardware, 17th February 2010 10:29 GMT

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Think SuperSpeed USB 3.0's 4.8Gb/s data transfer speed is lightning fast? You're wrong, says NEC.

Today it said it had successfully demo'd a serial bus that it believes can hit 16Gb/s.

Like USB 3.0 [1], NEC's technology sends data as a stream of binary 1s and 0s. NEC actually demonstrated a chip capable of maintain such a data rate, rather than a new bus per se, but it shows there's room for the likes of SuperSpeed - or its successor - to deliver even higher data-transfer speeds.

At high throughput rates, signals become distorted, especially over long cable lengths. Bus interface chips use 'adaptive equalisation [2]' to correct the distortion, and they do this by splitting the signal into two and feeding one back onto the input signal. The snag: the higher the frequency, the quicker the chip has to perform the feedback operation to successfully reduce the distortion.

NEC said it gets around this problem by adding a delay tied to the data rate to the feedback waveform.

"This procedure greatly reduces the nearest-neighbor inter-bit interference in the signal waveform and thus successfully alleviates the issue of feedback-time constraint inherent in conventional equalisers," said NEC's boffins.

Suffice it to say, the physics is complicated, the maths more so, but it works.

All NEC [3] needs do now, then, is wait for the bodies overseeing the specifications of standards like USB and PCI Express [4] to license its technique and boost the bandwidth of their buses. ®