'Super Speed' Unleashed with USB 3.0

Computing and consumer devices are increasingly becoming bandwidth intensive

and USB 3.0 is their answer. It allows much faster data transfer and better

power management over USB 2.0. The new version of USB also called SuperSpeed can

achieve a maximum theoritical tranfer speed of 4.8Gbps which is 10 times faster

than the 480Mbps offered by USB 2.0. Practically, it would achieve 3.2 Gbps or

more after including protocol overheads. This kind of speed is just about enough

to transfer a 25GB HD movie in about a minute. Of course, you won't be able to

maximize your bandwidth unless you're using a USB 3.0 cable with superspeed

devices and ports.

Backward compatibility



The new 3.0 connectors and cables will be physically and functionally

compatible with  older spec.  USB 2.0 cables worked off  four lines, USB 3.0

adds five new lines (the cable is noticeably thicker), but the new contacts sit

parallel to the old ones on a different plane. This means you'll be able to

differentiate between 2.0 and 3.0 cables just by looking at the ends.The five

new pins are situated deeper in the connector than the legacy pins, allowing the

deeper new connector to connect the extra pins.Your existing USB 2.0 gear will

work on version 3.0 ports and vice versa. Plugging a 3.0 device into a 2.0 port

or a 2.0 device into 3.0 a port will get you standard USB 2.0 data rates.

Bi-directional



The USB 3.0 protocol is now full-duplex; devices can send and retrieve data

simultaneously, which wasn't true with USB 1.1 and 2.0. That promises to allow

simultaneous downloading and uploading at fast speeds, a potentially tremendous

convenience.This is achieved by adding two new lanes dedicated to transmit data

and another pair for receiving it, bringing the total number of connections from

four on USB 2.0  to nine counting the 3.0 ground contact.

Power optimization



USB 3.0 cables facilitate carrying more power, too. Due to  the growing

number of portable devices that charge via USB, the USB 3.0 has acknowledged the

need for more charging options and have bumped the power output from about

100miliamps to 900 milliamps. That means not only will you be able to power more

devices from a single hub, but the increased current will let you charge up

hefty hardware as well.

USB 3.0 connector pins sit on a different plane allowing backward compability. The USB 2.0 port will be connected by the front legacy pins as always.

More power efficient



One of the mandates of the new spec is more efficient power-usage protocols.

USB 3.0 works on the principle of providing more power when required and wasting

lesser power when not required. USB 3.0 abandons device polling in favor of a

new interrupt-driven protocol, which means non-active or idle devices (which

aren't being charged by the USB port) won't have their power drained by the host

controller as it looks for active data traffic. Instead, the devices will send

the host a signal to begin data transfer. Minimum device operating voltage is

dropped from 4.4 V to 4 V.  New power management features include supports for

idle, sleep and suspend states, as well as link-, device-, and function-level

power management. Devices can communicate new information such as their latency

tolerance to the host, which allows better power performance.

Devices



High-bandwidth devices will  be among the first to migrate to the new

interface. The new interface will allow massive increase in external drive

performance, and drives will once again differentiate themselves on performance.

Solid state devices will benefit most from the speed boost.  External hard

drives capable of more than twice the throughput available from USB 2.0, and

bus-powered portable drives that require non-compliant Y-cables to get the

current they require for reliable operation will also benefit from the power

management option delivered by USB 3.0.

Besides storage, any high-bandwidth device that works with USB 2.0 will work

better if  updated with USB 3.0 support. Some possible applications include

high-resolution webcams, external Blu-ray drives, large LCD monitors capable of

being hooked up via a simple USB connection, digital cameras, video cameras and

more.

With its promised 4.8Gbps USB 3.0 will allow for consumer applications that

were either clumsy or downright unreachable before, like external RAID storage

systems. Photo libraries will transfer many times faster, and syncing video

content between devices will become more convenient.

Comparison with other similar technologies



'FireWire' is a highly efficient peer-to-peer, full-duplex, non-polling data

communications protocol with very low overhead. FireWire's P2P architecture can

achieve much closer to its theoretical 800Mbps data rate than the master/slave

architecture of the USB. FireWire 3200 promises a transfer rate of 3.2Gbps.

FireWire is able to produce about twice as much power as USB. FireWire 3200

is also backwards compatible with FireWire 800. But it should be noted that if

you have a new FireWire 3200 cable/device you can use it with your old FireWire

800 port and still achieve 3.2Gpbs speeds. This feature is a one up on USB 3.0.

Intel talks of a high-speed optical cable interface for PCs called 'Light

Peak' that promised a 10Gb/s transfer rate, or twice the speed of USB 3.0, with

the potential ability to scale to 100Gb/s. Light Peak is being developed as a

way to reduce the proliferation of ports on modern computers and could

eventually replace the plethora of interfaces currently used, from USB itself to

HDMI, DisplayPort,  LAN and so on. But until this comes up, USB 3.0 should be

the technology which takes the cake.