Why USB 3.1 is so important? USB has become the most important connection standard for all kinds of peripherals. Today, there are hardly any devices that do not use the Universal Serial Bus in any form for data exchange, device connection or voltage supply. Other interfaces such as the serial port, Parallelport or Firewire have practically disappeared. The only serious competition is Intel’s Thunderbolt. But this modern but also expensive connection variant plays practically no role outside the Apple world.
USB 3.1: The speed doubles
Already USB 3.0 was a huge leap at the maximum transfer rate from 480 MBit / s to 5 GBit / s. USB 2.0 was not even fast enough for mechanical hard disks with 480 MBit / s, but USB 3.0 is enough for an SSD. In addition, devices connected to a USB 3.0 port are now provided with at least 150 instead of 100 mA. Up to 900 mA at five volts are possible, with USB 2.0 it was still 500 mA.
USB Type C plug: Always fits
USB 3.1 brings a doubling of the performance up to 10 GBit / s, fast enough even for external drives with two SSDs in the RAID 0 network. In addition to this SuperSpeed Plus mode, USB 3.1 also supports the "normal" 5 GB SuperSpeed as well as the USB 2.0 standard and its predecessor.
Versatile: The Alternative Modes for USB Type-C
With a transfer rate of 10 Gbit / s, USB 3.1 is equal to the first Thunderbolt version developed by Intel. The new Thunderbolt 2 will deliver twice the transfer rate with 20 GBit / s. However, Thunderbolt and Thunderbolt 2 need expensive cables with electronic components in the connectors: A two meter long Thunderbolt cable from Apple costs 39 euros. USB 3.1, on the other hand, does not have any active cables. For a two-meter cable, this is about 10 euros.
Full power ahead: Power over USB
Who is not already cursed under the desk, when trying to insert a USB plug right on the back of his PC? Even worse is it with Micro-USB. Here you can squeeze the plug with enough force even upside down into the socket. That ruins in the best case only the plug, if one has bad luck but equal the whole smartphone. The new type C plug, on the other hand, can be plugged into its socket in both orientations; it works in any case. Here the USB Implementors Forum (USB-IF) has taken a meaningful bond with Apple's Lightning connector, which is also the case.
With an area of approximately 8.4 x 2.6 millimeters, which is necessary for the socket, the new Type-C is hardly any bigger than USB 2.0 Micro-B and is therefore well suited for flat mobile devices such as smartphones or tablets. It is more stable and supports SuperSpeed-USB. So far, the wider USB 3.0 micro-B connector was necessary.
In addition to a 15-core cable for SuperSpeed and SuperSpeed-Plus connections, the Type C specification also provides more affordable five-wire cables for USB 2.0 connections. The connectors and jacks are identical here, unlike Micro-USB.
The existing USB plugs and sockets are still part of the USB 3.1 specification and will by no means be completely replaced by Type-C. In addition, there are countless USB devices with older connections. There will therefore be a whole series of adapter cables and connectors for the connection between them: For USB 3.1 from C to Standard-A, Standard-B and Micro-B, for USB 2.0 it should be cables from C from Standard-A, standard -B, Micro-B and even Mini-B.
An adapter with a standard A jack and a mini B jack are also provided. The first is to support SuperSpeed-USB, the second is only USB 2.0.
Besides the pure data transmission, USB Type-C can also take on other tasks. They are implemented via function extensions, so-called alternative modes. The first of these alternative modes is the Audio Adapter Accessory Mode. It is intended to make the 3.5 mm audio jack unnecessary for future devices and also function via USB hubs. There will be a USB-type C adapter with a 3.5mm audio jack for connecting conventional headphones or speakers.
With DisplayPort Alternative Mode, the USB cable is used for the transmission of audio and video. If two of the four high-speed lanes in the cable are used for the display port transmission of 4K video, then the other two still can transfer Superspeed USB with 5 GBit / s. With 5K video, only USB 2.0 is possible at the same time.
In the normal case, a USB 3.0 or 3.1 port is designed to supply connected devices with a maximum of 900 mA at 5 volts, ie with 4.5 watts. This is, of course, not sufficient for many devices, which are therefore dependent on an additional power supply. In the case of USB connections, which follow the USB Power Delivery Specification (USB-PD) adopted in 2012, up to 100 watts can flow over the USB cable. In order to cover USB Type-C as well, a version 2.0 of the specification was just passed.
The USB PD specification defines five different profiles that can be used to power devices via USB with 10, 18, 36, 60 or 100 watts. Micro A / B connections, however, are limited to a maximum of three amps and thus 60 watts. Type-A / B and Type-C connections can flow up to five amperes at 20 volts.
For the 10 Watt profile, conventional USB cables are sufficient, all other profiles require special cables with better shielding. A USB-PD-capable device automatically detects which profile is supported by the cable. How much electricity can actually flow and in which direction is negotiated when connecting two USB-PD devices.
Until now, this USB-PD specification was hardly used by manufacturers of USB devices. With the introduction of USB Type-C, however, this should change. Combined with the DisplayPort Alternative Mode, USB-PD makes the ultimate docking station for notebooks or tablets possible via Type C cables. A single cable is then sufficient to bring a 4K video with audio to an external monitor, while simultaneously scrambling data at 5 GB / s to external drives and supplying the mobile device with the same power.
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