The third edition of USB is set to wow the world with phenomenal speeds, but its most appealing feature is complete backwards compatibility. This is made possible by a set of innovative standards and techniques used in the plugs and cables.

For years, USB 2.0 has been the most common and convenient way to connect peripherals to a PC. One can connect everything from a keyboard and mouse to an illuminated Christmas tree to a USB port! We can't imagine life without our convenient plug-n-play USB storage devices. webcams, and other devices.

The bit rate (max 480 Mb/s) offered by USB 2.0 is normally sufficient for most tasks, but its limits are now starting to be noticed in the age of HD videos, terabyte hard disks an,d hordes of digital photos. In September 2007, Intel announced it was beginning to define the specifications of USB 3.0, and now, at long last, the successor is ready.

January 2009 was the first time that a USB 3.0 device was demonstrated
in public. Seagate showed off its first external hard disk with a USB 3.0 controller. It will take time for USB 3.0 ports to show up on motherboards and maybe longer for devices to become available, but the technology is proven to be ready and working.

Data transfer: up to 5 per second

The most prominent feature of USB 3.0 is an enormous tenfold increase in the potential data transfer rate. Now up to 5 Gb/s of data (i.e. approximately 640 MB per second) can flow through a cable as compared to the 480 Mb/s in USB 2.0. This way USB 3.0 gets the better of its predecessors and FireWire, and also leaps ahead of SATA and eSATA ports, which currently manage up to 300 MB/s. The specialty of USB 3.0 is that it still remains compatible with older standards, which means that all current USB devices still remain fully functional.

USB 2.0 supports three different speed levels, mainly for backwards compatibility: "Low Speed" works at 1.5 Mb/s whereas "Full Speed" and "High Speed" manage 12 Mb/s and 480 Mb/s respectively. USB 3.0 also supports these three speed levels so that the USB 2.0 devices do not sense any difference. In addition to these. a "SuperSpeed" level is introduced. This is what enables a transfer rate of up to 5 Gb/s.

Contrary to the initial announcement, USB 3.0 does not require fiber optic cables to achieve such high data rates. The "SuperSpeed" mode operates with the help of the five additional pins in the connector. Furthermore the transmission frequency, which is in the high GHz range, requires the use of two additional shielded twisted pairs of wires in the cable; one for data transmission and the other for reception. The cable does require shielding to prevent interference and leaks.

The advantage of such complex cable structure is support for full-duplex data transfer, i.e. it can flow in both directions without compromising speed.

The connector: "extensions" for cell phones and printers:

The USB type A connector has plenty of space for the five additional SuperSpeed pins. such that its external shape can be retained without any changes. Keeping that in mind, USB 3.0 connectors should be blue in color to distinguish them from USB 2.0 connectors. which are usually black, white or Grey. The type B connector generally used for printers and hard drives is slightly enlarged in height to make room for the new pins. The micro USB connector designed for digital cameras or mobiles is unfortunately too small for the additional pins, and needs an "extension" to house them.

Features: data routing and a power saving mode:

Another innovation in USB 3.0 is the mode of data distribution in the USB "network". In all previous USB standards, up to 127 devices could be connected to a USB port and data was transmitted to all connected devices (polling). USB 3.0 transfers data only to and from the defined target device (routing) and will also allow devices to initiate contact, eliminating the need to constantly be polled. Each device will have its own communication path with the USB host. This saves bandwidth and power, USB 3.0 CABLE Data cable + (USB 2.0) • Data cable - (USB 2.0) Power (USB 3.0/2.0) • Ground (USB 3.0/2.0) Data reception - (USB 3.0) Data reception + (USB 3.0) Data transmission + (USB 3.0) since devices can be set in any of four different sleep modes. The new routing and the power saving functions will of course require new USB hubs.

Another improvement is that more power is now available for each device by default; in USB 2.0 this was 100-500 mA, whereas USB 3.0 devices can draw 150-900 mA. Although this is still insufficient for external 3.5-inch hard disks, it does improve stability for smaller devices.

Verdict:

We hope that USB 3.0 is adopted as fast as USB 2.0 was. Users will not face any inconvenience since USB 2:0 ports on motherboards can just be replaced in one shot and no backwards compatibility issues will arise. Peripherals will be able to run faster, especially hard drives. Besides, the standard has admirable new features such as the increased power draw support and a more robust way to string multiple devices together.

Current plans peg the availability of SuperSpeed USB at early 2010. Till then, we'll be waiting eagerly.