USB 2.0 Vs 3.0

All of us are familiar with USB i.e. the Universal Serial Bus. It is a specification used for data transfer between a variety of devices and computers. Nowadays, most of the modern-day devices and gadgets are provided with USB support which has made transferring data from one gadget to another a simple, fast and hassle-free business. The USB was invented and developed by an Intel Engineer named Ajay Bhatt. USB portable storage devices was an immediate hit among the consumers because of the satisfactory value for money factor. Let us have a look at the USB 2.0 vs 3.0 comparison through following paragraphs.

The USB specification gives the fastest rate of data transfer to and from various devices like digital cameras, mobile phones, desktop computers, MP3 players, laptops, external hard drives and cell phones.

The most widely used version of the USB is USB 2.0, whereas the latest version which has been recently introduced is the USB 3.0. We can have a comparative study of USB 2.0 vs USB 3.0 to find out the pros and cons of each of them.

Changes in USB 3.0

Let us first take a look at the variations introduced in the new USB standard. As compared to the USB 2.0 specification, the USB 3.0 has the following additional features.

• Super Speed: A greater and much better rate of signaling of 5Gbps as opposed to 625 Mbps of USB 2.0.
• Dual-bus architecture: The four distinct data rates are supported by USB 3.0

USB 2.0 and 3.0 Comparison

The comparison between USB 2.0 and 3.0 is carried out by means of points discussed below. One should be able to understand the difference, USB 2.0 and USB 3.0 in a better manner with this information.

Year of Release
The USB 2.0 was introduced in the year April 2000 which was just 4 years after its predecessor USB 1.0 which was brought out in the year 1996. USB 3.0 has been introduces after a large gap of 10 years after the 2.0.

Speed
The advent of USB 2.0 revolutionized the rate of data transfer by providing an amazingly high speed of 480 Mbps, as compared to the meager rate of 1.5Mbps-12Mbps offered by USB 1.0. After a lot of publicity and delays, the much awaited new specification of USB, i.e. the USB 3.0 was introduced. The USB 3.0 supports the super fast speed of 5Gbps. This makes the new USB 3.0 around ten times faster than the old USB 2.0.

Data Rates
There have been defined four distinct speeds of data transfer as low-speed, full-speed, high-speed and super-speed with maximum data throughputs of 1.25x, 10x, 400x and 4166.7x respectively, where, 1x=.15MB/sec. USB 2.0 supports low, full and high speed transfers, whereas USB 3.0 supports all four rates including the super-speed.

Real Data Throughput
The above data rates are theoretical, but it is found that in practical applications, the experimental values differ from theoretical values. The actual transfer rates of USB 2.0 Vs USB 3.0 are found to be around 35-40 MB/sec for the 2.0 specification and for 3.0, it may go well above 400 MB/sec.

Length of Cable
When USB cable are used for extension, sometimes a parallel cable problem is observed which may lead to data alterations. To avoid this problem, USB cable length limits has been imposed on the maximum length of cable. For USB 2.0 this length can be 5m whereas for USB 3.0, it can be 3m.

Power
The USB specification has an attractive feature where in the USB device can be powered by the PC or laptop that it is connected to.

Type of Transfer
The USB 3.0 supports a dual-simplex simultaneous bi-directional flow of data as opposed to the half duplex unidirectional flow of data in 2.0.

Power Requirement Comparison

The following table gives the power requirements of USB 3.0 vs USB 2.0.

Attributes	USB 2.0	USB 3.0
Suspended	2.5mA	2.5 mA
Unconfigured	100 mA	150 mA
Configured, low-power	100 mA	150 mA
Configured, high-power	500 mA	900 mA

The data presented in the form of USB 2.0 vs 3.0 article should help understand about the difference in these technologies. This comparison should help enhance knowledge about latest developments in the field of USB flash drive technology.