Say what? [LWN.net]

Say what?

Posted Jun 11, 2009 21:54 UTC (Thu) by sf_alpha (guest, #40328)
In reply to: Say what? by sbergman27
Parent article: Linux first to offer USB 3.0 driver (Linux Devices)

Real world speed measured from single devices. This explain why 10:1 ratio apply for typical USB 3.0 devices.

At time USB 2.0 released, most early generation controller does not have enough processing power and buffer to reach 100Mbps throughput. But now I can copy files from my USB 2.0 drives at 20MBPS++ (200Mbps++).

And ... USB 3.0 now support FULL-DUPLEX, real-world throughput is much improved and theorically may reach maximum throughput at 4Gbps+ if controller is good enough.

Bit rate is mostly describe rate of serial of bits that transfer on the wire. Byte per second is usually use to measure throughput of real data or payload.

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Say what?

Posted Jun 12, 2009 13:22 UTC (Fri) by clugstj (subscriber, #4020) [Link] (1 responses)

4Gbps full-duplex on a single wire? How do they do that, or did they add more wires for USB 3.0.

Four new wires

Posted Jun 12, 2009 14:17 UTC (Fri) by khim (subscriber, #9252) [Link]

4Gbps full-duplex on a single wire? How do they do that, or did they add more wires for USB 3.0.

Connector A, Connector B and Connector Micro B - two new wires for SuperSpeed Up and two new wires for SupeSpeed Down. Like Gigabit Ethernet, just shorter and few times faster...