USB ports are now part of our daily routine. They are the easiest and most used way to connect devices to a laptop. Whether it's a tablet, a camera, a keyboard, a mobile phone, all connect using a USB connector.
It was in 1996 that the first version of the Universal Serial Bus made its appearance. Its aim was to replace the very many connectors for the single use. Thanks to the emergence of the USB, the need for a plug for the keyboard, one for the mouse, one for the printer, etc. In addition, the USB port allows you to power the device at its end which allows it, for example, to power hard drives without requiring additional power cable, or to recharge your phone.
Yet there is not only one type or one format for the USB connector.
Indeed, since its creation the USB has evolved to adapt to its use and offer ever larger performances.
You have to know that there are two major differences in the USB cables. The first is the norm, it has evolved over the years and refers to the technology of the USB. The second is characterized by the connector: type-A, type-B, Micro-USB, or USB type-C.
The USB standards
USB 2.0
Since the year 2000, USB 2.0 is the norm for almost all devices.
It delivers higher performance than USB 1.0, which it replaces. The USB 2.0 allows data throughput up to 480 Mbps, when USB 1.0 offered a speed of 12 Mbps at full speed. The USB 2.0 also provides power to the device with a height of 2.5 W.
USB 3.0 or USB 3.1 GEN 1
Introduced in 2008, the USB 3.0 further increases the data transfer speed. Now, this technology allows (theoretical) transfers up to 5 gbits/S. The backward compatibility with the previous version (USB 2.0) is ensured. On the power transmission side, the USB 3.0 can now reach the 4.5 W, sufficient to power an external hard drive.
Note that the USB 3.0 designation has been officially reviewed by the USB-IF consortium, the new denomination is the USB 3.1 "Gen 1", not to be confused with the "Gen 2″ ..."
USB 3.1 GEN 2
The latest version of USB, announced in 2013, the USB 3.1 Gen 2 offers notable changes compared to its predecessors. The data transfer speed is doubled with respect to the USB 3.1 Gen 1, so it goes to 10 gbits/s. On the power supply side, the USB 3.1 offers 3 power profiles. Thus, it will recharge appliances equipped up to 100w! Currently, the Macbook Pro retina 12″ and the Google Chromebook Pixel 2 Use this technology to recharge their battery.
It is therefore important to distinguish between USB 3.1 Gen 1 (formerly USB 3.0), and the USB 3.1 Gen 2 which offers doubled bitrates from 5 to 10 Gbit/s, but not only, since the USB 3.1 Gen 1 can only transmit 4.5 W vs. 100 for Gen 2 ...
THUNDERBOLT 1, 2 and 3
The Thunderbolt is a connection protocol developed by Intel and Apple. In 2011, it teamed up for the first time the 15-inch Macbook Pro and the Mac Mini in the form of a mini DisplayPort connector. Thunderbolt 1 provides a theoretical throughput of up to 10 Gbit/s in data transfer, Thunderbolt 2 manages up to 20 Gbit/s on 2 channels. But that's not all because it can manage a video stream in addition to the data transfer. For example, you can connect a high-definition external display (2560 x 1600 pixels).
The other advantage of this protocol is to be able to chain peripherals: external hard disk, main screen, secondary screen, etc. Thunderbolt technology also makes it possible to use portable PC docking stations, so you only have one Thunderbolt cable to connect, the docking station connects with the rest of your equipment (keyboard, screen, external hard drive , etc.).
The new Thunderbolt 3 standard continues to flow with a maximum bandwidth of 40 gbits/s, this new standard is based on the DisplayPort 1.2 protocol, so you can manage the display of two screens at 4 K resolution or a single 5 K screen. The other novelty comes from its format because this new version now uses a Type C USB connector (instead of a Mini DisplayPort connector). As with USB 3.1 It allows the transfer of energy up to 100w.
This means that you can have a USB port Type C with the USB 3.1 compatible with the Thunderbolt 3 technology, provided that your connector is compatible with Gen 2 with maximum flowrates of 10 Gbit/s and has a Thunderbolt controller ... Are you still following?
The USB connectors
The opportunity is therefore perfect to talk about the last point of difference between the USB connectors: their format.
You'll probably notice, there are different sizes of USB connector, let's take a tour of the horizon:
Type A: The USB connector that everyone uses on a daily basis, it can use the USB 1.0, 2.0, or 3.1, it is present on your USB keys, for example
Type B: More compact than Type-A, this is the connector usually found to connect the devices (printer).
Micro B: Still a little more compact than Type-B, it is found on shelves or smartphones for data transfer or battery recharge. It succeeds the Mini-B and uses the USB 2.0 standard, better known as "Micro USB"
Micro B USB 3.0: present most often on external hard drives, it is an evolution of the Micro USB 2.0 but with the standard USB 3.0 (or 3.1 Gen 1), visually the connector is wider and designed in two parts, it allows to recharge your smartphone more. T in addition to having a higher flow rate
Type C: This new format replaces the type-A and type-B, it no longer knows the connection direction. So you don't have to turn the USB stick three times or its cable to finally find the right direction of connection, it passes every time! It use the USB 2.0 standard, USB 3.1 Gen 1 or 3.1 Gen 2 ... It could finally become the universal connection protocol even if the backward compatibility with previous format types is not ensured without the use of adapters (you cannot directly connect a USB-Type key in this connector)
Type C + Thunderbolt: This connector uses all the C-type (reversible) and Thunderbolt 3 (transfer speed, power transfer up to 100w, etc) arguments. It must incorporate a dedicated controller known as the Alpine Ridge code to be fully compatible Thunderbolt 3.
You will have understood, it is not because a laptop has a USB connector Type C 3.1, that it is necessarily compatible with Thunderbolt technology since the latter now uses the same connector, hence the confusion. Add to this, that a Type C connector (without Thunderbolt 3 compatibility) can use the USB standard 3.1 Gen 1, or its successor in Gen 2 and you have the recipe to confuse everyone ...
