USB types and standards. USB standards. New cables, connectors, color coding

New standard USB Type-C is still not widely developed on the market, but manufacturers are gradually adopting new technology. In smartphone industry USB-C already can be called a new trend because it is not only an improved charging port, but also a means of eliminating the traditional 3.5mm headphone port. Today we will talk in more detail about USB Type-C, and this article will tell you what it is.

Today almost everything electronic devices equipped with a USB connector. From desktop computers to smartphones and a variety of laptop storage devices. USB is a ubiquitous standard when it comes to connecting peripherals or transferring data between devices. Last thing major update USB came out in 2013 with the release of USB 3.1, accompanied by the release of a new Type-C connector. As you can see, almost 4 years have passed since then, and Type-C has not taken root.

Currently, you can count on one hand the number of devices on the market that use USB Type-C technology. Among computers this latest laptops from Apple, from Google, a line from Samsung and several more hybrid devices. Among the smartphones - mainly the flagships of the outgoing year:, and.

So why is USB Type-C better than its predecessors? Let's find out.

What is USB Type-C

USB Type-C is a new and currently actively developing industry data transfer standard for computers and mobile devices. The main and most significant innovation of Type-C is a modified connector - universal, symmetrical, capable of working on either side. The USB-C connector was invented by the USB Implementers Forum, a group of companies that developed and certified new standard USB. It also includes the largest technology companies, namely Apple, Samsung, Dell, HP, Intel and Microsoft. By the way, this is important to know, because USB Type-C was easily accepted by most PC manufacturers.

USB-C is the new standard

First of all, you need to know that USB Type-C is a new industry standard. Just like they once were USB 1.1, USB 2.0, USB 3.0 or the most latest usb 3.1. Only previous generations of USB were more focused on increasing data transfer speeds and various other improvements, while Type-C from a physical point of view changes the connector design in a similar way to technology modifications - MicroUSB and MiniUSB. However, the decisive difference is in this case is that, unlike MicroUSB and MiniUSB, Type-C is aimed at replacing absolutely all standards, on both sides (example USB-MicroUSB).

Main characteristics:

24 signal pins
USB 3.1 support
Alternate mode for implementing third-party interfaces
Speed up to 10 Gbps
Power transmission up to 100 W
Dimensions: 8.34x2.56 mm

USB Type-C and USB 3.1

One of the possible questions for those who do not know about USB Type-C could be something like this: what does USB 3.1 have to do with USB Type-C? The fact is that USB 3.1 is the main data transfer protocol for Type-C. The speed of version 3.1 is 10 Gbps - in theory, this is 2 times faster than USB 3.0. USB 3.1 can also be presented in the original connector format - this port is called USB 3.1 Type-A. But today it is much easier to find USB 3.1 with a new Type-C universal connector.

USB versions

To better understand why Type-C will become a replacement for traditional USB versions, it is first necessary to understand the difference between them. There are various USB versions, as well as even different connectors - for example, Type-A and Type-B.

USB versions belong to a common standard, but they differ in the maximum data transfer speed and operating power. Of course, there are many other factors.

USB 1.1
Although USB 1.0 is technically the first version of USB, it failed to fully reach the market. Instead, a new version of USB 1.1 was released - it became the first standard to which we are all accustomed. USB 1.1 can transfer data at 12 Mbps and consumes a maximum of 100 mA of current.

USB 2.0
The second version of USB was introduced in April 2000. It provided the standard with a significant increase in maximum data transfer speed - up to 480 Mbit per second. USB 2.0 has also become more powerful, consuming 1.8A at 2.5V.

USB 3.0
The release of USB 3.0 brought with it not only the expected improvements in data transfer speed and power, but also new types of connectors. Moreover, USB 3.0 even got its own color - new version The standard was marked blue to valiantly distinguish it from older generations of USB. USB 3.0 can operate at speeds of up to 5 Gbps, using 5V at 1.8A for its operation. By the way, this version was presented in November 2008.

USB 3.1
The newest and most best version USB was released in July 2013, although it is still not widely used. USB 3.1 can provide users with bandwidth up to 10 Gbps with maximum consumption energy in 5V/1A, or optionally 5A/12V (60 W) or 20V (100 W).

Type-A
Type-A is classic interface USB. The short and rectangular plug became original design for USB remains the standard connector for use at the host end of a USB cable to this day. There are also some variations of Type-A - Mini Type-A and Micro Type-A, but these have never been widely accepted by the public due to the complex nature of the socket. Currently, both of these Type-A variations are considered obsolete.

Type-B
If Type-A has become one side of the USB cable we are used to, Type-B is the other. The original Type-B is a tall connector with beveled top corners. Commonly found on printers, although itself an extension of the USB 3.0 standard to introduce new connectivity options. The classic MiniUSB and MicroUSB are also available in Type-B versions, along with the absolutely clunky MicroUSB 3.0, which uses additional plugs.

Type-C
Thus, after Type-A and Type-B we come, obviously, to the latest Type-C. Type-A and Type-B versions were supposed to work together with each other through backward compatibility, but the arrival of Type-C completely ruined these plans, since USB-C involves a complete replacement of outdated USB connection technologies. Also Type-C was specially designed to additional options like Mini or Micro did not need to be released at all. This, again, is due to the intentions to replace all current connectors with USB Type-C.

Main feature Type-C standard is the versatility or symmetry of the connector. USB-C can be used by both sides similarly Apple technology Lightning - no more special sides for connection, which are also difficult to find in the dark. Also, the Type-C version is based on USB 3.1, which means it supports all the benefits latest version, including the highest speed.

USB-C is still backwards compatible with existing USB variants, but this use case will of course require adapters.

Disadvantages of USB Type-C

Naturally, the new USB Type-C standard also has problems. One of the main and most serious concerns of the latest version of the technology is the physical design of the connector - it is very fragile due to its symmetrical design. Apple, despite the same versatility of its Lightning, uses a durable metal plug that is much more resistant to external influences.

An even more pressing and significant problem with USB Type-C is the unregulated operation of the connector, which has led to a number of dangerous accessories being marketed. Some of these accessories, by using unsupported voltage levels, can fry the connected device. For example, this was the case with the flagship, which was magnificent at the start, which subsequently began to first ignite and then completely explode in the hands, trousers, cars and apartments of its owners.

This problem led to an obvious and only solution - a massive ban on the production and sale of non-original accessories with USB support Type-C. Thus, if an accessory does not meet USB Implementers Forum Inc. standard specifications, the product will not be approved for sale. Also, to check the operating status and authenticity of various third-party accessories, USB-IF has introduced software protected by 128-bit encryption, which will allow devices with this connector to automatic check connected device or accessory with USB-C.

Minuses:

Design. The design of USB Type-C is good, but the design has suffered - it is quite fragile. Apple uses an all-metal plug in its Lightning, while Type-C uses an oval shape with the signal pins placed in the central part.
Connector operation. Allowing USB Type-C to operate at unsupported voltage levels will likely cause the cable and/or device to catch fire.
Compatibility. USB Type-C is an innovation in the USB world, but newest generation leaves old devices in the past because it does not support working with them.
Adapters. For full-fledged work with USB Type-C on older devices you will have to buy additional adapters. This is an additional waste of money.

Benefits of USB Type-C

Despite all of the above, USB Type-C can confidently be called a step forward for the industry. Installing this connector will allow manufacturers to make thinner computers and mobile devices with fewer ports, higher data transfer speeds and headphones. In the future, if USB Type-C becomes popular, the connector will be able to replace not only the 3.5 mm headphone port, but also HDMI, the interface used for video transmission. Thus, USB Type-C will replace the connectors that are familiar today and will become a universal standard in any situation.

Pros:

Symmetry. USB Type-C allows you to forget about situations where you have to remember which side to insert the cable into the connector. Also, from now on you don’t have to worry about not finding the right side of the USB in the dark.
Compactness. The dimensions of USB Type-C are 8.4x2.6 mm - this allows manufacturers to make computers and mobile devices much thinner.
Versatility. Thanks to the integration of a single connector, it will become possible charging with one cable for both a laptop, a tablet or a smartphone.

In fact, the new USB 3.1 standard and the Type-C connector should calm down the mess and restore order. For everything about everything - one single cable: for data transmission, audio, video signals and power supply. The symmetrical Type-C connector is a real blessing for mobile device users who are tangled in wires. And the USB 3.1 standard allows, for example, to play video from a tablet on a TV while the mobile device is charging.

Just the transition to new specifications poses additional difficulties for manufacturers, which is why sellers and buyers immediately become disheartened. Companies cannot be blamed for lack of interest: after entering the market MacBook Pro(2015), many manufacturers have introduced products that support the new USB 3.1 standard with a Type-C connector, including devices such as motherboards, monitors, external drives and smartphones. Thus, the LG G6 is equipped with a USB Type-C connector, as well as HTC 10 and Samsung Galaxy S8, which connects to the docking station via a universal connector, turning into a full-fledged Personal Computer. But new form does not always mean new functions: for example, Type-C in the Huawei version does not support USB 3.1, but for fast charging generally uses its own technology.

Old devices are a hindrance to new standards

Variety of connectors
Many USB devices still come with one of the old connectors. Type-C should replace them all

Technical breakthroughs always take a very long time if there is a large stock of old technology. Keyboards, mice, external drives, webcams, digital cameras, USB flash drives - millions of these devices still require support for older versions of USB. The problem could be temporarily solved by using universal adapters, but completely new devices with old USB ports are still being released.

And since regular USB cable it is not so easy to distinguish the host from the client device; to this day it requires as many as two different types connectors. That's why external hard drives often come with Mini-A connectors, and printers with typical quad Type-B connectors. Sooner or later, USB Type-C should replace not only these connectors - using a cable it would be possible, for example, to connect peripheral devices to a PC without any problems. Moreover, Type-C can send DisplayPort, HDMI and even TRS jacks into oblivion.

Don't be confused: Type-C is not USB 3.1

"Talking" logos
Logos should reflect what functionality the USB connector provides. Unfortunately, not all manufacturers use them

Since the USB consortium approved two other specifications at the same time as the Type-C connector, there is often some confusion in the concepts. Firstly, we have a new Type-C connector with a mirror arrangement of 2x12 pins, making the port insensitive to the orientation of the plug - which means that the problem of “how to plug in a USB Type-A plug the first time” will be available very soon forget.
Secondly, along with the new connector, a new USB 3.1 standard has been introduced, increasing the data transfer rate ceiling to 10 Gbps (gross).

Further, USB power supply Power Delivery (USB-PD) is presented in a new, second revision: it involves accelerating the charging of connected devices by increasing power (20 V, 5 A instead of the previous 5 V, 0.9 A). In other words, even though USB Type-C, USB 3.1 and USB Power Delivery are often identified; they are not equivalent terms or synonyms. So, there is, for example, a USB 2.0 interface in Type-C format or a USB 3.1 port without support for Power Delivery fast charging.

But that is not all. The consortium cannot be completely blamed for the mess, since it has moved away from using the usual nomenclature: with the advent of USB 3.1, USB 3.0 ceased to exist in the sense that this previous version is now classified as USB 3.1 Gen 1, and the newly introduced technology is called USB 3.1 Gen 2. But many USB cables and devices are sold under the name USB 3.1 - without specifying which generation they are referring to.

The USB Consortium, however, has developed a system of logos to designate USB Type-C connectors so that you can distinguish, for example, a Type-C plug supporting USB 3.1 Gen 1 from a plug supporting USB 3.1 Gen 2 or even old USB 2.0, but first you need to carefully study the logos. It's not uncommon to have to look at the manual to figure out which version you're using - unless, of course, detailed documentation is available. It's not surprising that many manufacturers continue to use the previous name USB 3.0.

Limit values of USB versions
USB 3.1 Gen 2 doubles data transfer speeds and increases current for fast charging

To all this diversity should be added Thunderbolt interface 3, developed primarily by Intel and Apple. Thunderbolt from the third version also uses a Type-C connector, but is not entirely compatible with USB 3.1. With active Thunderbolt 3 cables, throughput reaches up to 40 Gbps (gross), four times that of USB 3.1. This not only provides very high data transfer speeds, but will also allow you to transfer multiple video streams with 4K content over DisplayPort and even use external graphics cards. Complex technologies require the use of active electronics in cables. USB devices can be connected to the Thunderbolt 3 port, but never vice versa.

Difficult choice of cables

The confusion doesn't stop with standards and versions alone. If previously you could limit your choice to one USB cable with the right types connectors, with USB 3.1 and Type-C it will not be so easy. Here, as in the case of standards and versions, there is currently a huge lack of information: not all Type-C cables can transmit data, video and supply power. In many cases, it is not clear to users whether a Type-C cable supports Power Delivery fast charging or an alternative mode for video transmission, because logos and markings, as a rule, are simply not there.

Premium motherboards
Currently, USB 3.1 Gen 2 is supported only by select premium motherboards. Among them is Asus Rampage V 10, equipped with two Type-A and two Type-C ports, it costs about 38,500 rubles

It is often impossible to determine whether a cable supports USB 3.1 or just USB 2.0. On the Amazon website, there are very often reviews from upset customers who, after purchasing, discovered that the purchased cable does not support the fast charging technology of their smartphones. Even the designation by some manufacturers, for example, Aukey, of a USB 3.1 Gen 1 cable with Type-C and Type-A ends as a “Type-C to USB 3.0 cable” does not help to get out of this difficult situation at all - this is completely wrong.

If you decide to get a device with a Type-C connector, be sure to make sure that the package includes a cable - only then will all your requirements be satisfied. Equipment supplier for computer equipment Hama, for example, offers several Type-C cables with detailed characteristics, but prices start from 1000 rubles. Buying a Thunderbolt 3 cable will cost even more – you will need to shell out about 2,000 rubles. But all the functions are provided here. If this price is too high, then willy-nilly you will have to rummage through product descriptions and customer reviews about them in search of the right cable.

USB-C: balanced plug

Data transfer, power supply and dialogue between devices - each of the 24 pins of the Type-C plug performs a separate function. It is easy to notice that their arrangement is symmetrical.

Displays, laptops and adapters

To transfer video in one of the alternative modes (DisplayPort or HDMI), that is, for example, from a laptop to a monitor, you should also pay attention to the technical requirements. There are currently several monitors on the market with a USB Type-C connector from LG, Eizo, Acer and HP (for example, Envy 27, about 40,000 rubles). For video output, the DisplayPort standard is almost universally used, which indeed works quite reliably. But if we talk about fast charging, which places special demands on the monitor’s power supply, then in many cases buyers have questions.

Alt mode video
The USB-C connector, for example, like that of the LG 27UD88 (about 38,000 rubles), usually provides reliable video transmission to the monitor, but it does not always provide fast charging with Power Delivery

However, supplying power from the monitor to the laptop is not always necessary. The Asus MB169C+ portable 15-inch monitor (about 15,000 rubles) receives power from the laptop via a fully used Type-C connector.
One way or another, nowadays it often happens that a laptop with a USB Type-C connector is connected to a monitor via HDMI port or DisplayPort. In such cases, an adapter is required that converts the video signal and transmits it to the monitor using the desired standard. Such accessories can be purchased from about 1000 rubles. Compared to other cables, choosing adapters is quite simple, because their task is only to convert the video signal without taking into account other features of USB 3.1.

For those interested in a laptop or tablet with a Type-C connector, the choice is currently limited, but great. In addition to the MacBook (12 inches), there are hybrids Acer Aspire Switch 10 V (about 25,000 rubles) and Asus T100HA (about 18,000 rubles). And the young Google Pixel Chromebook is equipped with two whole Type-C ports (though only of the USB 3.1 Gen 1 standard), but it has not yet gone on official sale in Russia.

Old documentation
Even though the Acer Aspire Switch 10 V only has one Type-C port, the manual lists older types of USB connectors

Probably, it is unlikely that any user will dare to transfer all their peripheral devices to Type-C at once, so most laptop owners will need to start USB adapter 3.1 for data and video transmission via USB Type-A, HDMI or DisplayPort cable. Prices for recommended flexible models start at 2,500 rubles, such as the Icy Box IB-DK4031. Club 3D SenseVision is more expensive - about 6,500 rubles - but it includes HDMI, DVI, USB 3.0 Type-A, 4 USB 2.0 connectors, USB fast charging, as well as jacks for connecting a microphone and headphones.

Less rich in currently choice for desktops: traditionally, motherboard manufacturers introduce new standards in premium models. The only one motherboard with four USB ports 3.1 Gen 2 (two each Type-A and Type-C) is the Asus Rampage V 10, which costs about 38,500 rubles. At least an indication of fast transfer 10 Gbit/s is also located on the panel of interface connectors. One USB 3.1 option from the bottom price category desktops is MSI X99A SLI (LGA 2011-3) with one Type-A and one Type-C port for about 15,000 rubles.

Universal adapter

Switching to computers with a Type-C connector will require an adapter with different types of ports for the peripherals.

> Club 3D SenseVision (about 6500 rubles)
The adapter is relatively expensive, but is equipped big amount ports, including HDMI, DVI, microphone and headphone jacks, as well as four USB 2.0 ports and a fast charging connector (USB 3.1 Gen 1)

> Icy Box IB-DK4031 (about 2500 rubles)
A simpler version of the adapter with a Type-A connector (USB 3.1 Gen 1), HDMI,
as well as a Type-C connector with Power Delivery for fast charging of external devices.

Benefit from external storage thanks to USB 3.1

Fast memory
USB 3.1 Gen 2 gives many external SSDs, such as the Freecom mSSD MAXX, a significant jump in speed

Of course, network storage with a RAID configuration and external drives, primarily flash memory - solid-state drives and USB flash drives, benefit from the high data transfer speeds of USB 3.1 Gen 2. But for the latter, the availability of USB 3.1 Gen 2 is currently reduced to zero. The offered flash drives from SanDisk, Kingston and Corsair, positioned as USB 3.1, transfer data at a speed of no more than 5 Gbit/s, that is, they belong to the first generation. However, for most flash drives this should be sufficient for now.

As for external solid-state drives, the manufacturers Freecom (mSSD MAXX, about 8,000 rubles) and Adata (SE730, about 9,500 rubles) offer drives with USB 3.1 of the second generation. The first practical tests show that the high-speed interface does indeed provide significantly higher data transfer rates. Terramaster offers a housing for network storage D2-310 with two compartments (about 10,000 rubles) with support for USB 3.1 Gen 2, on which high-speed SATA drives in a RAID array should also make a good impression.

Music over USB-C
The score has been opened for the headphone jack on a smartphone: a Type-C to TRS adapter will soon appear as standard

It should be separately noted that memory manufacturers do the best job of specifying versions and standards and are the least likely to leave their customers halfway. The remaining manufacturers must urgently supplement the documentation and properly implement the standards.

Transitioning from one generation of technology to the next has always been a long and often confusing process, but not since the days of VHS and Betamax has there been such confusion as now. Someday, the USB 3.1 / Type-C configuration will really make life easier for everyone - especially users, but for now there are many difficulties to be overcome.

PHOTO: CHIP Studios; Freecom; Stouch; Club 3D; Raidsonic; Acer; LG; Asus; Sabrina Raschpichler

Currently, there are several types of USB connectors (Universal Serial Bus), which come in three versions - USB v1.1, USB v2.0 and USB v3.0. Version v1.1 is practically not used due to the too low data transfer speed (12 Mbit/s), so it is used only for compatibility.

The second version of USB 2.0 now dominates the market. Majority modern devices support this version, which provides an information exchange speed of 480 Mbit/s, which is equivalent to a copy speed of 48 MB/s. However, due to non-ideal implementation and design features, on practice real speed rarely exceeds 30-33 MB/sec. Many hard drives are capable of reading information at 3-4 times faster speeds.

The USB v2.0 connector is a bottleneck that slows down the operation of modern drives. At the same time, for mice, keyboards and some other devices this does not matter much. The third version of USB v3.0 is marked in blue, which indicates that it belongs to to the last generation. The bandwidth of the third version of USB provides a speed of 5 Gbit/s, which is equivalent to 500 MB/s. Taking into account the fact that modern hard drives have a speed of 150-170 MB/sec, the third version of USB has a large reserve of data transfer speed.

Structurally, USB 1.1 and 2.0 versions are fully compatible with each other. If one of the connected parties supports version v1.1, then data exchange will occur at a reduced speed, and operating system will display the message: “The device can run faster,” which will mean that the computer is using a fast USB 2.0 port, and the connected device version 1.1 is slow. Compatibility between USB 2.0 and 3.0 looks a little different. Any USB device v2.0 can be connected to the third version port, indicated in blue. But the reverse connection (with the exception of type A) is impossible. Modern USB v3.0 cables and devices include additional contacts, which allow you to increase the speed of the interface.

USB power

Any USB connector is powered by a voltage of 5 V and a current of up to 0.5 A, and for USB version 3.0 - 0.9 A. In practice, this means that the maximum power of the connected device does not exceed 2.5 W or 4.5 W for USB 3.0. For this reason, connecting low-power and portable devices(phones, players, flash drives, memory cards) will not cause problems, and large and massive equipment is powered from an external network.

USB v2.0 and USB v3.0 connectors are also classified by type (Type A and Type B) and size (MiniUSB and MicroUSB).

The USB Type A connector is the most widespread and is the most recognizable among the existing ones. Most devices (mice, keyboards, flash drives, cameras and many others) are equipped with USB type A, which was developed back in the 90s. The main advantage of this port is its reliability, which allows it to withstand a large number of connections without losing integrity. Although the cross-section of the connector is rectangular, it is protected against incorrect connection, so it’s impossible to stick it in reverse side. However, it is quite large in size, so it is not suitable for portable devices, which has resulted in the creation of smaller modifications.

The USB type B connector is less popular. All modifications of type B, including Mini and Micro, have a square or trapezoidal shape. The traditional full-length Type B is the only type that has a square cross-section. Due to its rather large size, it is used in various peripheral and large-sized stationary devices (scanners, printers, sometimes ADSL modems). Typically printer manufacturers or multifunctional devices Their products are rarely equipped with such a cable, so the buyer has to purchase it separately.

The reason for the appearance of tiny Mini USB Type B connectors was the abundance of miniature devices on the market. And the appearance of portable hard drives ensured their real mass popularity. Unlike large connectors with 4 pins, Mini USB Type B has five pins, however, one of them is not used. Unfortunately, miniaturization has had a negative impact on reliability. During operation, after some time the Mini USB connector begins to loosen, although it does not fall out of the port. At this time, it is still actively used in portable hard drives, players, card readers and other compact equipment. The second modification of Mini USB type A is almost never used. Mini USB is gradually being replaced by a more advanced modification, Micro USB.

The Micro USB type B connector is a modified version of the previous type Mini USB type B and has very miniature dimensions, which allows manufacturers to use it in modern technology with a small thickness. Thanks to the improved fastening, the plug sits very tightly in the socket and does not fall out of it. In 2011, this type of connector was approved as uniform standard for charging smartphones, phones, tablets, players, etc. portable equipment. This solution allows you to charge your entire fleet of electronics using one cable. The standard is showing growth trends and it can be assumed that in a few years almost all new devices will be equipped with it. Type A is used extremely rarely.

The USB 3.0 standard provides significantly higher data transfer speeds. Additional contacts, which made it possible to increase speed, led to a change in the appearance of almost all USB connectors of the third version. However, type A has not changed in appearance, except of blue color cores. This means that backward compatibility is maintained. In other words, a USB 3.0 Type A device can be plugged into the port USB second versions and vice versa. This is the main difference between the connector and other version 3.0 connectors. Such ports are usually found in modern laptops and computers.

USB 3.0 type B is used in medium and large high-performance peripheral devices - NAS, as well as in stationary hard drives. The connector has undergone major changes, so it cannot be connected to USB 2.0, in particular to USB 2.0 type B. Cables with such connectors are also not often sold.

Micro USB 3.0 is the successor to the “classic” Micro USB connector and has the same characteristics - compactness, reliability, high-quality connection, but at the same time provides higher data transfer speeds. Mainly used in modern external super high speed hard drives and SSD. It is becoming increasingly popular. The connector largely duplicates Micro USB version 2.

Users sometimes confuse Mini USB connectors with Micro USB connectors, which are really similar. The main difference is that the first one is slightly larger in size, and the second one has special latches on the back side, which make it easier to distinguish these two types of connectors. In other respects they are identical. Today there are many devices with these types of connectors, so it is preferable to have two different cables.

At the end of 2008. As might be expected, the new standard has increased throughput, although the increase is not as significant as the 40x increase in speed when moving from USB 1.1 to USB 2.0. In any case, a 10x increase in throughput is welcome. USB 3.0 supports maximum speed 5 Gbps transfers. Bandwidth is almost twice the current standard Serial ATA(3 Gbit/s taking into account the transmission of redundancy information).

USB 3.0 logo

Every enthusiast will confirm that the USB 2.0 interface is the main bottleneck. modern computers and laptops, since its peak “net” throughput ranges from 30 to 35 MB/s. But modern 3.5″ hard drives for desktop PCs already have transfer speeds exceeding 100 MB/s (2.5″ models for laptops are also appearing, approaching this level). High-speed solid-state drives have successfully surpassed the 200 MB/s threshold. And 5 Gbit/s (or 5120 Mbit/s) corresponds to 640 MB/s.

We don't think that in the foreseeable future hard disks will approach the 600 MB/s level, but the next generations of solid-state drives may exceed this number in a few years. Increasing throughput becomes increasingly important as the amount of information increases and the time it takes to back it up increases accordingly. The faster the storage works, the shorter the backup time will be, the easier it will be to create “windows” in the backup schedule.

Speed comparison table USB characteristics 1.0 – 3.0

Digital video cameras today can record and store gigabytes of video data. The share of HD video cameras is increasing, and they require more capacious and fast storage for recording large quantity data. If you use USB 2.0, then transferring several tens of gigabytes of video data to a computer for editing will require considerable time. USB Implementers Forum believes that bandwidth will remain fundamentally important, and USB 3.0 there will be enough for everyone consumer devices over the next five years.

8/10 bit encoding

To ensure reliable data transfer USB 3.0 interface uses 8/10 bit encoding, familiar to us, for example, from Serial ATA. One byte (8 bits) is transmitted using 10-bit encoding, which improves transmission reliability at the expense of throughput. Therefore, the transition from bits to bytes is carried out with a ratio of 10:1 instead of 8:1.

Bandwidth comparison USB capabilities 1.x – 3.0 and competitors

Power Saving Modes

Certainly, main goal interface USB 3.0 is to increase the available bandwidth, however, the new standard effectively optimizes energy consumption. The USB 2.0 interface constantly polls for device availability, which consumes energy. In contrast, USB 3.0 has four connection states, named U0-U3. The connection state U0 corresponds to active data transfer, and U3 puts the device into “sleep”.

If the connection is idle, then in state U1 the ability to receive and transmit data will be disabled. State U2 goes one step further by disabling the internal clock. Accordingly, connected devices can transition to the U1 state immediately after data transfer is completed, which is expected to provide significant power consumption advantages when compared to USB 2.0.

Higher current

Except different states energy consumption standard USB 3.0 is different from USB 2.0 and higher supported current. If USB 2.0 provided a current threshold of 500 mA, then in the case of the new standard the limit was shifted to 900 mA. The connection initiation current has been increased from 100 mA for USB 2.0 to 150 mA for USB 3.0. Both parameters are quite important for portable hard drives, which usually require little high currents. Used to be a problem was solved by using an additional USB plug, drawing power from two ports but using only one for data transfer, even though this violated the USB 2.0 specifications.

New cables, connectors, color coding

USB 3.0 standard is backward compatible with USB 2.0, that is, the plugs appear to be the same as regular Type A plugs. USB pins 2.0 remained in the same place, but five new contacts are now located in the depth of the connector. This means that you need to insert the USB 3.0 plug all the way into the USB 3.0 port to ensure the mode USB operation 3.0, which requires additional pins. Otherwise you will get USB 2.0 speed. USB Implementers Forum recommends that manufacturers use color coding Pantone 300C on the inside of the connector.

The situation was similar for the USB type B plug, although the differences are visually more noticeable. A USB 3.0 plug can be identified by five additional pins.

USB 3.0 does not use fiber optics, because it is too expensive for the mass market. Therefore, we have the good old copper cable. However, it will now have nine rather than four wires. Data transmission is carried out over four of the five additional wires in differential mode (SDP–Shielded Differential Pair). One pair of wires is responsible for receiving information, the other for transmitting. The principle of operation is similar to Serial ATA, with devices receiving full bandwidth in both directions. The fifth wire is “ground”.

If you meet in technical devices designation: USB Type-A, USB Type-B or USB Type-C, this means that the USB device uses these types of connectors.
This is not a designation for the USB standard, it is a designation for the type of connector.

USB standards or their versions are designated as follows: USB 1.0, USB 1.1, USB 2.0, USB 3.0 and USB 3.1.
Moreover, USB 3.1 has two versions: USB 3.1 Gen 1 and USB 3.1 Gen 2.

The most well-known type of USB connector is USB Type-A, it is located on flash drives, USB modems, and at the ends of the wires of mice and keyboards.

It is used for the USB 1.0, USB 1.1, USB 2.0 and USB 3.0 standards.
For USB 1.0, USB 1.1, USB 2.0 the connector is black, and for USB 3.0 it is blue.
Thanks to the USB connector Type-A devices Compatible with standards up to USB 3.0.

The USB Type-C connector is different from the previous ones and is not compatible with them.

If there is a need to combine, then you need to use the appropriate adapters.

An important advantage of the USB Type-C connector is that it is symmetrical.
Now you no longer have to worry about which side to insert the cable into the device, i.e. The type C plug can be inserted either way into the socket.

Now let's look at the difference between USB standards.
Theoretical data transfer rate:

USB 1.0 up to 1.5 Mbps
- USB 1.1 up to 12 Mbps
- USB 2.0 up to 480 Mbps
- USB 3.0 and USB 3.1 Gen 1 up to 5 Gbps
- USB 3.1 Gen 2 up to 10 Gbps

Supply voltage, maximum current and power consumed by the peripheral device:

USB 1.0, USB 1.1 - up to 150 mA 5 V (0.75 W)
USB 2.0 - 5V to 500 mA (2.5 W)
USB 3.0 - 5V to 900 mA (4.5 W)
USB 3.1 Current @ 1.5 A - 5V to 1.5 A (7.5 W)
USB 3.1 Current @ 3 A - 5V to 3A (15 W)
USB 3.1 (with Power Delivery 2.0 support) and depending on Profile:
Profile1 - 5V 2A (10 W)
Profile2 - 5V 2A, 12V 1.5A (18 W)
Profile3 - 5V 2A, 12V 3A (36 W)
Profile4 - 5V 2A, 12V, 20V 3A (60 W)
Profile5 - 5V 2A, 12V, 20V 5A (100 W)

The power profile system has been introduced for more advanced cases; for standard devices, Profile1 is used.
For example, an advanced case can be considered active usb cable for 100 meters, having at both ends a converter of USB interface signals into optical and vice versa ( maximum length standard USB cable cannot exceed 5 meters).
Such a cable transmits only data, and power is needed for the converters.

Therefore, it is necessary to know the power profiles of both the peripheral devices being connected and the main device to which the connection is made.
A port on a device corresponding to a higher-level profile maintains all states of the previous ones downstream.

For example, a device with any profile can be connected to a device with Profile5.
Please note that the usb cable must also match the power profile if you connect peripheral device increased power.

One final note.
The presence of a USB Type-C connector on a device does not mean that this port on the device operates according to the USB 3.1 standard.