USB 2.0 vs USB 3.0 Latest technology Updates

What is USB?

USB stands for Universal Serial Bus. Popular USB versions USB 2.0 & USB 3.0.

Difference between USB 2.0 & USB 3.0

The USB 3.0 specification was published on 12 November 2008. Its main goals were to increase the data transfer rate (up to 5Gbps), to decrease power consumption, to increase power output, and to be backwards-compatible with USB 2.0.[7] USB 3.0 includes a new, higher speed bus called SuperSpeed in parallel with the USB 2.0 bus.[8] For this reason, the new version is also called SuperSpeed.

Points:

USB 2.0 has a maximum data transfer speed of 480mbps, and FireWire 800 has a maximum speed of 800mbps. USB 3.0 shatters those speeds with a maximum data throughput of 4.8gbps! yes, that’s 4,800mbps!

USB 3.0 Specifications

USB 3.0 is introduced now to increase the data transfer speed in minimum time with decreasing power consumption. Here are the specifications of USB 3.0

• Transfer Rate
  Data transfer rate of USB 3.0 is maximum 4.8 Gb/s.
• Data Transfer
  USB 3.0 introduces full duplex data transfer. Two of five lanes are reserved for transmitting data, while another pair is dedicated to receiving data, meaning that USB 3.0 can read and write data simultaneously at full speed. Previous USB specifications did not support bi-directional data transfer.
• Power
  The unit load has been increased to 150 mA and a configured device can draw up to six unit loads, which adds up to 900 mA. This exceeds USB 2.0 by 80% and leads to faster recharging or powering of more than four devices from a single hub. In addition, the minimum device operating voltage was dropped from 4.4 V to 4 V, which saves energy.
• Power Management
  USB 3.0 suspends device polling, which is replaced by interrupt-driven protocol. As a result, idle devices won’t experience a power drain since a signal from the device is required to initiate data transfer. With USB 2.0 the host controller used to look for active transfers, slowly draining power. Briefly, USB 3.0 supports idle, sleep, and suspend states, as well as link-, device-, and function-level power management.
• Physical Appearance
  The above described specifications are also represented in the physical appearance of USB 3.0. While the cable was previously described to be thicker because it contains four more wires than USB 2.0, this appears not to be the case now. The plug, however, is a dead giveaway for USB 3.0. It contains an additional set of connectors, as illustrated in the image below.

Positive Points:

New technology is very exciting. But what does it mean? Will you still be able to use your old USB hardware? How will the new USB technology affect your everyday life? What are the benefits?

• Compatibility
  USB 3.0 is backwards compatible with USB 2.0. So whether you get a new USB 3.0 device or a new computer that supports USB 3.0, your old device will be able to communicate with the new interface. Naturally, it will do so at the old USB 2.0 speed. However, you won’t be able to use a USB 3.0 cable to connect a USB 2.0 device.
• Transfer Rate
  Now I bet all this Megabit and Gigabit per second numbers sound impressive, but what does it actually translate to? Well, let me give you an example. With USB 3.0 you could transfer a 10 GB file from your computer to an external drive in approximately 25 seconds. With USB 2.0 this would take more than five minutes.
• Benefits
  The devices that will benefit most from USB 3.0 are those that already outspeed USB 2.0, including HD webcams, Blu-Ray drives, or some external hard drives.
• Support by Operating Systems
  Windows Vista, Windows 7, and Linux already support USB 3.0. Mac is expected follow. Given its age, Windows XP will probably not receive an update to support the new interface.

Negative Points:

I was tempted to report that there is no bad news, but that’s not true. Let’s say bad news is minimal.

• Cable
  The maximum cable length USB 3.0 supports is reduced to approximately three meters, opposed to five meters with USB 2.0. However, using hubs, the maximum length can be extended to 18 meters.
• Speed Limit
  Naturally, not all devices will be able to make use of the increased speed in USB 3.0. Magnetic hard drives for example, are limited by their RPM and the corresponding read/write speed. Hence, USB 3.0 will not unfold its full beauty until computers are equipped per default with faster hardware, such as solid state drives. But we all know how speedy progress is in the IT world. Give it a year or two and you will be able to fully benefit from USB 3.0.