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 technology was invented and developed by an Intel engineer named Ajay Bhatt. USB portable storage devices were 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 the 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 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 these 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.
- Super Speed: A greater and much better rate of signaling of 5 Gbps as opposed to 625 Mbps of the earlier version.
- Dual-bus architecture: The four distinct data rates are supported by USB 3.0
Year of Release
The USB 2.0 was introduced in April 2000, which was just 4 years after its predecessor 1.0, which was brought out in the year 1996. 3.0 has been introduced after a long gap of 10 years after the 2.0.
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 its predecessor. After a lot of publicity and delays, the much awaited new specification, the USB 3.0, was introduced. It supports the super fast speeds of up to 5Gbps. This makes it around ten times faster than its predecessor.
There are four distinct speeds of data transfer, namely, 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. 2.0 supports low, full, and high speed transfers, whereas 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 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 cables 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 have been imposed on the maximum length of cable. For 2.0 specification, this length can be 5m whereas for USB 3.0, it can be 3m.
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
|Attributes||USB 2.0||USB 3.0|
|Unconfigured||100 mA||150 mA|
|Configured, low-power||100 mA||150 mA|
|Configured, high-power||500 mA||900 mA|
This comparison should help enhance your knowledge about the latest developments in the field of USB flash drive technology.