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