BY STEVE SMITH
Faster-than-ever downloads from consumer devices are on the horizon as a result of the recently finalized USB 3.0 connectivity specification, but actual products aren’t expected until later this year and more likely in 2010.
In mid-November, the USB 3.0 Promoter Group–comprised of Hewlett Packard, Intel, Microsoft, NEC, ST-NXP Wireless, and Texas Instruments–announced completion of 3.0’s technical roadmap, paving the way for device manufacturers to deliver 10x file transfer speed improvement over USB 2.0. For next-generation computers and personal electronic devices, downloads and file transfers are targeted to be about 5 Gbits/sec. An hour’s worth of downloaded TV programming will take about 3 seconds, compared to about 20 seconds for USB 2.0.
According to the specification, USB 3.0 cables have eight primary conductors–three twisted signal pairs for USB data paths, and a power pair. In addition to the twisted signal pair for the USB 2.0 data path, two twisted signal pairs are used in 3.0 cables to provide what the Group calls the “SuperSpeed” data path–one for transmit path, and one for receive path.
Both upstream and downstream USB 3.0 connector receptacles are compatible with 2.0 connector plugs, but are not intended to be compatible with 2.0 upstream receptacles. A dual-bus architecture incorporates USB 2.0 and a SuperSpeed bus, which is designed for activation of each of the buses independently and provides for the attachment of USB devices to the highest speed bus available for a particular device. The layered communications architecture is comprised of the SuperSpeed interconnect, which is the manner in which devices are connected to and communicate with the host over the SuperSpeed bus; devices that provide information exchanges between a driver on the host and a logical function on the device; and a host, which “owns the SuperSpeed data activity schedule and management of the SuperSpeed bus, and all devices con- nected to it.”
Some industry observers say that USB 3.0 is targeted more at next generation flash-based devices, and that 2.0 still remains effective for most current applications. While the Promoter Group says 3.0-based cables and connectors will be backward compatible with 2.0-based devices, Superspeed USB connectivity aims to answer an anticipated consumer demand for “how fast can we go?” before the question is asked.
“Today’s consumers are using rich media and large digital files that need to be easily and quickly transferred from PCs to devices and vice versa,” explains USB Implementers Forum president and chairman Jeff Ravencraft of Intel. He says the new specification aims to meet the needs of “everyone from the tech-savvy executive to the average home user.”
The group, which is now accepting early adopters, believes that USB 3.0 discrete controllers could appear on the market by late this year, with likely initial consumer devices being data storage-based, such as flash drives, external hard drives, digital music players, and digital cameras. CS
