USB 2.0 vs. USB 3.0 vs. USB 3.1
If you spend a considerable amount of time researching new consumer gadgets or shopping for new devices, you may have heard about various USB ports and standards. If you are not a techie, the different versions can confuse you.
Each version represents the speed and function of the cable. Over the years, the trusty USB standards have undergone significant changes. The changes are mostly in terms of data transfer speeds and power.
There are many devices supporting USB, and you need to be up-to-date with the latest developments. This article will give you a detailed description of these 3 USB standards, their speeds, pros, and cons. This will help you make an informed decision if you are planning to buy a new device soon.
Brief History of USB
Universal Serial Bus is a world-famous port standard that has been in use for almost 20 years. It was developed in the '90s to define communication protocols. The protocols include connectors and cables between a computer and electronic devices like scanners and printers. Over time, devices increased in types and quantities. The USB port was then adopted as the preferred connection portal.
Today, devices like smartphones, tablets and video game consoles can easily connect to computers with USB ports. The USB ports allow users to recharge and communicate, replacing the need for adapters and power chargers.
That said, let us now break down the 3 USB standards:
USB 2.0
USB 2.0 was released back in April 2000. It features a speed of 480 Mbps. It uses a polling mechanism signaling method which means that it can only handle one direction of data at any given time.
It either sends or receives data. Most manufacturers no longer use this port. It is less expensive than the other two ports. Power usage for USB 2.0 is up to 500 mA. It also conserves power when the connected device is in idle mode. The standard-A connectors are grey in color and it has 4 wires within the cable. The standard-B connectors are smaller in size when compared to the other standards. The maximum cable length is 5 meters.
USB 3.0
The third-generation USB interface, called "SuperSpeed USB 3.0" (SS USB) was released in November 2008, exactly 8 years after the release of USB 2.0.
It is compatible with USB 2.0 and is also known as USB 3.1 Gen 1. It is 10 times faster than its predecessor. To be precise it has a speed of 4.8 Gbps. It incorporates an asynchronous mechanism which means more bandwidth. The two unidirectional data paths mean that it can send and receive data simultaneously. When you transfer data through USB 3.0 cables, connectors and devices, the host initiates the transaction by making a request. This is followed by a response from the device which can be either rejection or acceptance. If accepted, the device can send and receive data from the host.
A Not Ready (NRDY) signal implies that there is limited buffer space or data. The device will send an Endpoint Ready (ERDY) signal to the host when the device is ready. This will then reschedule the transaction. In terms of pricing, it is normally more expensive than the USB 2.0 version. It provides up to 900 mA of power. It can power more than one devices from one hub. It provides better power efficiency. It has 9 wires within the cable. The standard-A connectors are blue in color. The standard-B connectors are bigger than the ones in USB 2.0 to provide more space for more wires. The maximum cable length is 3 meters.
USB 3.1
USB 3.1 was released in July 2013. It is the most recent version of the USB and is also known as USB 3.1 Gen 2. It is easily recognizable by its bright turquoise port. It offers significant improvements over its predecessor. For starters, it uses a C-type connector. A C-type connector allows users to plug in with no regard to orientation. It has the highest data transfer speed of the three at an incredible 10 Gbps.
To achieve this transfer speed, your device, USB host connection and cables must all support USB 3.1. The speeds deliver enhanced data encoding and efficiency. It also has the capacity to power any device. The C-type connector in USB 3.1 is small and used in most slim devices like MacBooks, smartphones, and tablets. With an amazing 100 watts of charging power, USB 3.1 can power any type of device. It is fully backwards compatible with the other standards. It has the ability to carry HDMI video signals.
Conclusion
USB connection has taken in many forms over the years. Most people are familiar with the rectangular USB Type-A ports common in computers, routers, and car chargers. Peripherals like printers and external hard drives use the blocky and square-shaped Type-B. The small and compact Type-C was recently developed to save the day. It replaces both Type-A and B. USB Type-C is being adopted as the universal port for all devices due to its reversibility feature and other benefits. As we enter 2018, expect more laptops, smartphones, and tablets to be equipped with USB Type-C ports.
