USB 3.0 vs USB 3.1 | Strengths and Improvements

Being ubiquitous in everyday life for around 24 years, the USB interface has been used widely for connecting modern electronic devices like computers, power banks, video games, Hard disks, digital cameras, and so on for file transfer, OS installation, and many more. Manufacturers of USB are continuously working on developing the data transfer speed, functionality, and power management of the USB interface. There are different USB standards proposed since 1996, and here we’ll talk about USB 3.0 vs USB 3.1.

The nomenclature proposed by the USB Implementation forum these days is a little weird and recondite. Different USB standards named with numbers refer to generations developing with mostly data transfer capability, power supply specifications, and function rather than physical shape. On the other hand, different USB types like Type-A, Type B, etc. are not the same as USB standards, they only indicate USB connectors and ports type based on physical shape.

USB 3.0 vs USB 3.1 both are widely used USB standards nowadays. If you are inquisitive to dig deeper and want to distinguish these two, you have arrived in the right place. We will try to alleviate this confusion with USB 3.0 vs USB 3.1 in-depth comparison in the next sections of the article.

USB 3.0

USB 3.0 is the third and major proposed version of the Universal Serial Bus standard to interface with computers and other electronic devices. Most of the modern devices are compatible with it. The official name was USB 3.1 Gen 1 previously which was rebranded as USB 3.2 Gen 1 after the launching of USB 3.2. USB 3.0 is often known as the marketing name SuperSpeed USB for higher speed than previous versions.

Windows-8 was the first Microsoft OS to support USB 3.0 and then Linux Kernel included built-in support since 2009. It was first shipped by Buffalo Technology, a Japanese Computer Peripheral Company. This was introduced with increased bus power, faster speed, improved power management.

The number of pins used in this standard is 9. Though this doesn’t specify any maximum cable length, the upper limit is considered to be 10 feet in implementation.  The width of USB 3.0 ports or connectors is 12 nm for Type-A, 8nm for Type-B, 12.2 nm for Micro-A & Micro-B plug.

Data Transfer Speed

the theoretical data transfer speeds up to 4.8 Gbit/s. So, theoretically, a 1.5 GB video can be transferred in less than a second, which is impractical. 3200 Mbps is considered more reasonable for USB 3.0 in everyday use.

It is found from a test conducted by Macworld, a 10 GB file can be transferred with 114.2 Mbps taking roughly 87 seconds. This super data transfer speed makes USB 3.0 10 times faster in data transfer and charging than USB 2.0.

Data Transfer Method

USB 3.0 is designed with two unidirectional data paths to offer increased bandwidth: one is dedicated to receiving data and the other is for transmitting data. This addition of a physical bus is the reason behind the increase in the amount of wire to 8. There is no need for polling as a new feature lets a device notify asynchronously the host of readiness.

The transaction is started with a host request followed by a response. STALL handshake in response means the endpoint is halted. Not Ready signal is given when there is a lack of buffer space or data. The host gets an Endpoint Ready signal when the device is ready and it reschedules the transaction. Up to 900mA provided by this standard allows devices to be bus-powered.

The data transfer takes place as a stream of eight-bit segments. These segments are then encoded into 10-bit symbols.  The stream protocol allows a large number of logical streams within an Endpoint. It is operated in full-duplex mode.

Compatibility of USB 3.0

This offers backward compatibility with USB 2.0 using dual bus architecture. So, the older version is adaptable with it but it will work at the original speed. Also, USB 3.0 hard drives can be connected to a USB 2.0 port but will work with the USB 2.0 data transfer speed. However, to avoid any possible damage, USB 3.0 cables and USB 2.0 peripherals are so designed that they cannot be connected.

There are four types of USB 3.0 connectors available which include male connectors called plug and female connectors called port or receptacle. Type-A, Type-B, Micro-A, Micro-B connectors are supported in the USB 3.0 standard. Mini-A, Mini-B, Mini-AB receptacles are not included in this specification. To connect a USB Type-C connector, a suitable adapter or cable is required.

How Can You Identify USB 3.0?

You can identify USB 3.0 on your computer by checking the device manager or the manufacturer sheet of the device. A super-easy way to tell if the device supports USB 3.0 is checking the inside of the connector. USB 3.0 connectors are distinguished by manufacturers using a bright blue color. Or a “SS” (SuperSpeed) initial is printed on the USB 3.0 cable or near the USB3.0 port.

USB 3.1

USB 3.1 is the successor of USB 3.0 which is officially known as USB 3.2 Gen 2. The former name of USB 3.1 was USB 3.1 Gen 2. The USB-IF planned to establish USB 3.1 as SuperSpeed USB+ for marketing purpose, but never caught on. USB 3.1 standard was introduced in July 2013. Since then the past few years, USB 3.1 is slowly being implemented in modern devices which will eventually replace the previous ones.

Power Delivery 2.0 allows compatible ports to give up to 100 watts to the connected device. So, this allows the charging of larger devices like laptops and tablets using a single USB 3.1 cable.  Also, this allows for type-C cables to add an HDMI or DisplayPort video signal. The number of pins used in the plugs and receptacles of USB 3.1 standard is 9 which is similar to that of USB 3.0.

Data Transfer Speed

The data transfer speed is up to 10Gbps rivaling the speed of Ethernet and the original thunderbolt. The devices with USB 3.1 host can achieve the USB 3.1 transfer speed. But this speed indicates the theoretical maximum and unlikely to be found in everyday use. But still, this standard is faster than the previous USB 3.0 only.

Data Transfer Method

USB 3.1 implements two blocks: a control and a data block. This offers a new encoding scheme named 128b/132b. that means 128 bits are represented by 132 bits on the line resulting in 3% Bandwidth overhead. In these 132 bits, 128 bits are payload and 4 bits are used as header identifying the data or control block. The design is capable to correct bit flips.    

Compatibility of USB 3.1

USB Type-B 3.1 cables are not adaptable with USB Type-B 2.0 ports. Type-C cables or ports only support Type-A and Type-B ports or cables here if a suitable adapter is used. Devices based on USB 3.1 may not work or show a lag in performance while working with previous USB versions. Other than these special cases, USB 3.1 is backward compatible.

Along with USB type-C connector, it supports many other connector types like Type-A, Type-B, and Micro-B. But only Type-C connectors are capable to handle the full power and bandwidth of USB 3.1 standard.

How can you identify USB 3.1?

Turning to the hardware, USB 3.0 and USB 3.1 are identical. While no official color has been assigned for the insert, manufacturers like Asus has adopted light blue or bright turquoise color to distinguish USB 3.1 standards ports and plugs. You can also identify a USB 3.1 port on your computer if there is a logo as shown below near the port.

Comparison of USB 3.0 and USB 3.1

Wrap Up

After USB 1.0 and 2.0, USB 3.0 was launched with a major improvement in speed and performance. Between USB 3.0 vs USB 3.1, USB 3.1 is the real successor of USB 3.0 with a huge improvement in data transfer speed and power management. USB 3.1 is gradually being implemented in most of the devices and it can be anticipated that in the future all the electronic devices will use this standard of interface universally. But, from 2009 till now, USB 3.0 is widely seen in every modern device.