Storage

SuperSpeed USB 3.0: More Details Emerge

Intel's Jeff Ravencraft, who is also president of the USB Implementers Forum, discussed more details about USB 3.0 today at the Storage Visions conference in Las Vegas.

The focus of the new spec is three-fold: Retain backward compatibility, increase speed, and provide better power handling.

"USB has been the most successful interface in history of personal computing," Ravencraft noted. "Over 6 billion products are in the market, and over 2 billion ship a year now."

Compatability

Backward compatibility shows up in the new standard. USB 3.0 maintains the extensive device class driver infrastructure of USB 2.0, and a USB 2.0 devices will work via a 3.0 connector.

Performance

Performance improvements are notable, too. "We have research that shows that after 1 minute, 1.5 minutes waiting for a transaction, users get impatient.," says Ravencraft. "The transfer times have to get much faster." Hence the evolution of USB SuperSpeed's Sync & Go concept.

SuperSpeed USB 3.0's 5Gbps data rate (compared with Hi-Speed USB 2.0's 480Mbps) should help--and with very clear real-world advantages. For example: A 25GB HD movie will take 13.9 min to transfer with USB 2.0, and 70 seconds with USB 3.0, says Ravencraft.

Practically speaking, the implications are tremendous. Imagine not having to wait hours on end for your full-drive data backup to complete, or not having a lengthy delay when off-loading 32GB flash memory cards from your digital camera.

Power

As for power consumption, "power today is king for portable devices. It is the pinnacle, the focus for the PC, the notebook, and all devices. All of these new specs had to be optimized for power efficiency," says Ravencraft.

For example, there's no longer any device polling, so connected USB devices can enter a virtual sleep mode; more power will be able to go to the device (which will hopefully eliminate some of the power issues we see today with portable hard drives that require extra power from a second USB port); and USB 3.0 will no longer broadcast information to all connected devices, thereby saving power, too. Plus, when a device's battery is drained, it will now still be recognized by a laptop, for example, so you can charge it (this doesn't work with USB 2.0).

The intention is for SuperSpeed USB 3.0 to provide headroom for the next five years.

"We've designed the protocol so it should operate at up to 25 gigabit per second data rates if the pipe supplies that type of data rate," says Ravencraft. "I don't think we'll get to that over a copper wire, but we might look at an optical interface next. And we're ready if it does."

Ravencraft expects host controllers and device controllers by mid-2009, and consumer products by early 2010. His estimates are more conservative than those offered by Symwave, which is demonstrating USB 3.0 at CES 2009 in conjunction with Seagate.

For more news from CES, check out our complete coverage of CES 2009.

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