The Universal Serial Bus, which we all know by its acronym USB, is by far the most important standard for connecting peripheral devices such as printers, smartphones, keyboards or external storage devices. It was born almost 25 years ago – in 1996 the first USB specification 1.0 was released, at that time an incredible revolution. At last it was possible to exchange data between two devices via a serial interface.
Today, USB interfaces have become an integral part of everyday life. Basically, they are used for any device that can communicate with the computer in any form. The latest interface is called USB-C and was released in 2014. We want to give you a short overview of what makes USB-C so exciting and how all the fun is connected to USB 3.0, USB 3.1 and USB 3.2.
What happened so far – the predecessors of the USB-C type
For a better understanding of the new interface, we must first take a look at the predecessors USB-A and USB-B. Caution: We are only talking about the USB hardware (the physical interfaces: plugs, sockets, cables etc.) and not about the data transfer technology (the USB versions/specifications). We will tell you more about data transfer technology in the following.
The USB revolution began with the USB-A plug, which is still widely used today. USB-A is mainly used for host devices like computers and notebooks. The best known application of USB-A is probably the universally popular USB stick.
The USB-B is the standard port for peripherals ranging from smartphones and tablets to speakers and cameras. In addition to the normal B-connector, there are also the Mini-B and Micro-B versions, which are found on charging cables or some external hard drives, for example. Their slim and compact form is perfectly suited to small, flat devices. As a side note: There are now also micro and mini connectors for USB type A, but these are much less frequently used.
The exact design, colour coding or even pin number of the individual plug connections (or sockets) depends, among other things, on the particular USB version for which they are designed. This means: A USB 1.0/2.0 type A plug is mechanically and optically different from a USB 3.0 type A plug.
USB Type C and its technologies
Technologies are the respective protocols or specifications that underlie a USB connection and transmit specifications for transfer speed and power supply. The earlier versions 1.0, 1.1 and 2.0 offered transfer rates of just 12 Mbps (1.x) to 480 Mbps (2.0) with a power supply of 100-500 mA – absolutely useless for charging for larger power guzzlers.
With the introduction of USB 3.0, USB 3.1 and USB 3.2 this has fortunately changed. USB 3.1 and the USB-C connector were released in 2013/2014 to define a universal, powerful and future-proof USB standard. Ideally, this will enable transfer speeds of up to 10 Gbit/s, and with USB 3.2 even 20 Gbit/s.
The individual version numbers are now encountering a great deal of confusion, as new names and designations have been juggled with over the past few years. When USB 3.1 came on the market, the so-called generations were introduced: USB 3.0 was suddenly USB 3.1 Gen 1 and USB 3.1 was from now on USB 3.1 Gen 2. With the release of USB 3.2, the USB Implementers Forum (USB-IF) found that there must be new names, which in the meantime pose some puzzles for some users.
The following table should help you to find your way through the name jungle of USB specifications. In any case, you can see that the version number itself does not really say anything about the actuality of the specification, but primarily about the generation. So: Always look at the generation!
|old designation||New designation||transmission rate (max.)|
|USB 3.0||USB 3.1 Gen 1||USB 3.2 Gen 1||5 Gbit/s|
|USB 3.1||USB 3.1 Gen 2||USB 3.2 Gen 2||10 Gbit/s|
|USB 3.2||–||USB 3.2 Gen 2×2||20 Gbit/s|
The strengths and weaknesses of USB-C
Now that we’ve taken a closer look at the development of earlier USB connectors and technologies, we’ll turn to the exciting and actual part of this article: the strengths and weaknesses of USB-C. The USB-C connector in combination with its specification USB 3.1/USB 3.2 Gen 2 brought some new features that might have pleased some end users. First, a list of all the special features that distinguish USB-C from its predecessors:
- Torsion-proof coupling: USB-C connections consist of 24 pins arranged in a point-balanced manner and are therefore completely identical at the top and bottom. This means for you: It doesn’t matter how around the plug goes into the socket, because there is no longer the one correct method. A Meme era comes to an end with this.
- Compact size: At just 8.4 x 2.6 millimetres, USB C connectors are almost as small as the micro B connectors and therefore extremely practical for small and flat mobile devices. The continuing trend towards ever more compact end devices will sooner or later ensure that the C standard will replace its predecessors USB-A and USB-B.
- Faster data transfer: USB-C usually comes with the latest specifications USB 3.2 Gen 2 or Gen 2×2, which allows a maximum data transfer rate of 10 or 20 Gbit/s. In practice, this is less the case, but it is still much faster than the transfer rates of earlier versions.
- Power Delivery Specification (USB-PD): An additional specification that only occurs with type C connectors and was developed as part of the USB 3.2 Gen 2 version is the Power Delivery Specification. It can be used to supply power not only to smartphones but also to larger devices such as notebooks and printers (in extreme cases with up to 100 watts). In order to use this variable power supply, not only the USB-C cable used but also the respective devices must be PD-compatible. You can see this when the logo next to the socket is embedded in a black battery symbol.
Despite all the praise, there are also two points to consider with USB type C in order to be able to use the interface optimally:
- USB C is not always the same as USB C: A USB C port only ever delivers as much power as its underlying protocol. So in order to really use these interfaces, you should always use the latest protocol, but at least USB 3.2 Gen 2. Some smartphones are advertised with advanced USB C ports, but use older technologies, thus losing many of the advantages and features of USB C. If you want to be sure that the excellent USB C interface can also transfer 20 Gbps, you should pay attention to the exact generation (Gen 2×2) and the additional designation “Superspeed++”.
- USB C is not backward compatible: Although USB C ports technically work with older versions such as USB 2.0 or USB 3.2 Gen 1 (apart from the performance losses), from a physical point of view USB A or USB B cables can no longer be used. Therefore, the introduction of the USB-C interfaces has created quite a lot of new cable tangle, because the lack of backward compatibility can only be overcome with adapter cables, hubs or multifunction adapters.
It is certain that USB Type C will play a decisive role in the design and development of future end devices and technologies. The much-discussed demand of the EU Commission for uniform charging cables and connections could also contribute in the near future to finally unifying the various USB plugs and components into a common interface. Whether this will also affect Apple’s own Lightning connector is still to be decided.