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USB 3.0, released in November 2008, is the third major version of the
Universal Serial Bus Universal Serial Bus (USB) is an industry standard ''Industry Standard'' is a 1982 album by Dixie Dregs, The Dregs. It is their only album featuring vocals (by Alex Ligertwood of Santana (band), Santana and Patrick Simmons of The Doobie Bro ...
(USB) standard for interfacing computers and electronic devices. Among other improvements, USB 3.0 adds the new transfer rate referred to as ''SuperSpeed USB'' (SS) that can transfer data at up to 5 
Gbit/s In telecommunications, data-transfer rate is the average number of bits (bitrate), characters or symbols (baudrate), or data blocks per unit time passing through a communication link in a data-transmission system. Common data rate units are multip ...
(500 
MB/s In telecommunications, data-transfer rate is the average number of bits (bitrate), characters or symbols (baudrate), or data blocks per unit time passing through a communication link in a data-transmission system. Common data rate units are multip ...
after encoding overhead), which is about 10 times faster than Hi-Speed (maximum for USB 2.0 standard). It is recommended that manufacturers distinguish USB 3.0 connectors from their USB 2.0 counterparts by using blue color for the Standard-A receptacles and plugs, and by the initials ''SS''. USB 3.1, released in July 2013, is the successor standard that replaces the USB 3.0 standard. USB 3.1 preserves the existing ''SuperSpeed'' transfer rate, giving it the new label ''USB 3.1 Gen 1'', while defining a new ''SuperSpeed+'' transfer mode, called ''USB 3.1 Gen 2'' which can transfer data at up to 10 Gbit/s over the existing USB3-type-A and
USB-C USB-C (formally known as USB Type-C) is a 24-pin USB Universal Serial Bus (USB) is an industry standard ''Industry Standard'' is a 1982 album by Dixie Dregs, The Dregs. It is their only album featuring vocals (by Alex Ligertwood of Sa ...

USB-C
connectors (1200 MB/s after encoding overhead, more than twice the rate of USB 3.0). USB 3.2, released in September 2017, replaces the USB 3.1 standard. It preserves existing USB 3.1 ''SuperSpeed'' and ''SuperSpeed+'' data modes and introduces two new ''SuperSpeed+'' transfer modes over the
USB-C USB-C (formally known as USB Type-C) is a 24-pin USB Universal Serial Bus (USB) is an industry standard ''Industry Standard'' is a 1982 album by Dixie Dregs, The Dregs. It is their only album featuring vocals (by Alex Ligertwood of Sa ...

USB-C
connector using two-lane operation, with data rates of 10 and 20 Gbit/s (1200 and 2400 MB/s after encoding overhead). This specification has been renamed to reflect the evolution of "generations" of USB standards (ie: USB3.2Gen1 is "SuperSpeed", USB3.2Gen2 is also "SuperSpeed", but 2x faster, USB3.2Gen2x2 is also marketed as "SuperSpeed" but is 4x faster than 3.2Gen1). Nomenclature has been broadly criticized by both experts in the industry and the public at large for its confusing revisions not reasonably or appropriately reflecting the marketing messages that the guidelines prescribe in the standard specification, which is published at usb.org


Overview

The USB 3.0 specification is similar to USB 2.0, but with many improvements and an alternative implementation. Earlier USB concepts such as endpoints and the four transfer types (bulk, control,
isochronous A sequence of events is isochronous if the events occur regularly, or at equal time Time is the continued of and that occurs in an apparently succession from the , through the , into the . It is a component quantity of various s used ...
and interrupt) are preserved but the protocol and electrical interface are different. The specification defines a physically separate channel to carry USB 3.0 traffic. The changes in this specification make improvements in the following areas: * Transfer speed USB 3.0 adds a new transfer type called SuperSpeed or SS, 5 Gbit/s (electrically, it is more similar to PCI Express 2.0 and
SATA Serial ATA (SATA, abbreviated from Serial AT Attachment) is a computer bus In computer architecture In computer engineering, computer architecture is a set of rules and methods that describe the functionality, organization, and implemen ...

SATA
than USB 2.0) * Increased bandwidth USB 3.0 uses two unidirectional data paths instead of only one: one to receive data and the other to transmit * Power management U0 to U3 link power management states are defined * Improved bus use a new feature is added (using packets NRDY and ERDY) to let a device asynchronously notify the host of its readiness, with no need for polling * Support for rotating media the bulk protocol is updated with a new feature called Stream Protocol that allows a large number of logical streams within an Endpoint USB 3.0 has transmission speeds of up to 5 Gbit/s, about ten times faster than USB 2.0 (0.48 Gbit/s) even without considering that USB 3.0 is
full duplex A duplex communication system 400px, Communication system A communications system or communication system is a collection of individual telecommunications network A telecommunications network is a group of nodes interconnected by links ...
whereas USB 2.0 is
half duplex A duplex communication system 400px, Communication system A communications system or communication system is a collection of individual telecommunications network A telecommunications network is a group of nodes interconnected by links ...
. This gives USB 3.0 a potential total bidirectional bandwidth twenty times greater than USB 2.0.


Architecture and features

In USB 3.0, dual-bus architecture is used to allow both USB 2.0 (Full Speed, Low Speed, or High Speed) and USB 3.0 (SuperSpeed) operations to take place simultaneously, thus providing
backward compatibility Backward or Backwards is a relative direction Body relative directions (also known as egocentric coordinates) are orientation (geometry), geometrical orientations relative to a body such as a human person's. The most common ones are: left ...
. The structural topology is the same, consisting of a tiered star topology with a root hub at level 0 and hubs at lower levels to provide bus connectivity to devices.


Data transfer and synchronization

The SuperSpeed transaction is initiated by a host request, followed by a response from the device. The device either accepts the request or rejects it; if accepted, the device sends data or accepts data from the host. If the endpoint is halted, the device responds with a STALL handshake. If there is lack of buffer space or data, it responds with a Not Ready (NRDY) signal to tell the host that it is not able to process the request. When the device is ready, sends an Endpoint Ready (ERDY) to the host which then reschedules the transaction. The use of
unicast image:unicast.svg, Unicast is data transmission from a single sender (red) to a single receiver (green). Other devices on the network (yellow) do not participate in the communication. In computer networking, unicast is a One-to-one (communication ...

unicast
and the limited amount of
multicast In computer networking A computer network is a set of computer A computer is a machine that can be programmed to carry out sequences of arithmetic or logical operations automatically. Modern computers can perform generic sets of ...

multicast
packets, combined with asynchronous notifications, enables links that are not actively passing packets to be put into reduced power states, which allows better power management.


Data encoding

The ''"SuperSpeed"'' bus provides for a transfer mode at a nominal rate of 5.0 Gbit/s, in addition to the three existing transfer modes. Accounting for the encoding overhead, the raw data throughput is 4 Gbit/s, and the specification considers it reasonable to achieve 3.2 Gbit/s (400 MB/s) or more in practice. All data is sent as a stream of eight-bit (one-byte) segments that are scrambled and converted into 10-bit symbols via
8b/10b encoding In telecommunication Telecommunication is the transmission of information by various types of technologies over wire A wire is a single usually cylindrical A cylinder (from Greek Greek may refer to: Greece Anything of, from, o ...
; this helps the receiver to decode correctly even in the presence of
electromagnetic interference Electromagnetic interference (EMI), also called radio-frequency interference (RFI) when in the radio frequency Radio frequency (RF) is the oscillation Oscillation is the repetitive variation, typically in time, of some measure about a cent ...
(EMI). Scrambling is implemented using a free-running
linear feedback shift register In computing Computing is any goal-oriented activity requiring, benefiting from, or creating computing machinery. It includes the study and experimentation of algorithm of an algorithm (Euclid's algorithm) for calculating the greatest com ...

linear feedback shift register
(LFSR). The LFSR is reset whenever a COM symbol is sent or received. Unlike previous standards, the USB 3.0 standard does not specify a maximum cable length, requiring only that all cables meet an electrical specification: for copper cabling with AWG 26 wires, the maximum practical length is .


Power and charging

As with earlier versions of USB, USB 3.0 provides power at 5 volts nominal. The available current for low-power (one unit load) SuperSpeed devices is 150 mA, an increase from the 100 mA defined in USB 2.0. For high-power SuperSpeed devices, the limit is six unit loads or 900 mA (4.5  W)—almost twice USB 2.0's 500 mA. USB 3.0 ports may implement other USB specifications for increased power, including the USB Battery Charging Specification for up to 1.5 A or 7.5 W, or, in the case of USB 3.1, the
USB Power Delivery Specification The initial versions of the USB standard specified connectors that were easy to use and that would have acceptable life spans; revisions of the standard added smaller connectors useful for compact portable devices. Higher-speed development of t ...
for charging the host device up to 100 W.


Availability

The USB 3.0 Promoter Group announced on 17 November 2008 that the specification of version 3.0 had been completed and had made the transition to the
USB Implementers Forum The USB Implementers Forum (USB-IF) is a nonprofit organization A nonprofit organization (NPO), also known as a non-business entity, not-for-profit organization, or nonprofit institution, is a legal entity organized and operated for a collect ...
(USB-IF), the managing body of USB specifications. This move effectively opened the specification to hardware developers for implementation in future products. The first USB 3.0 consumer products were announced and shipped by Buffalo Technology in November 2009, while the first certified USB 3.0 consumer products were announced on 5 January 2010, at the Las Vegas
Consumer Electronics Show CES (formerly an initialism for Consumer Electronics Show) is an annual trade show A trade fair (trade show, trade exhibition, or trade exposition) is an exhibition organized so that companies A company, abbreviated as co., is a legal e ...
(CES), including two motherboards by Asus and
Gigabyte Technology Gigabyte Technology (branded as GIGABYTE or sometimes GIGA-BYTE; formally GIGA-BYTE Technology Co., Ltd.) is a Taiwanese Taiwanese may refer to: * Something from or related to Taiwan (Formosa) * Taiwanese aborigines, the indigenous people of Taiwan ...
. Manufacturers of USB 3.0 host controllers include, but are not limited to,
Renesas Electronics is a Japanese semiconductor A semiconductor material has an Electrical resistivity and conductivity, electrical conductivity value falling between that of a Electrical conductor, conductor, such as metallic copper, and an insulator (electricit ...
, Fresco Logic,
ASMedia ASMedia Technology Inc. () is a Taiwanese Taiwanese may refer to: * Something from or related to Taiwan (Formosa) * Taiwanese aborigines, the indigenous people of Taiwan * Han Taiwanese, the Han people of Taiwan * Taiwanese people, residents of Ta ...
, Etron,
VIA Technologies VIA Technologies Inc. (), is a Taiwan Taiwan, officially the Republic of China (ROC), is a country in East Asia East Asia is the eastern region of Asia Asia () is Earth's largest and most populous continent, located primari ...
,
Texas Instruments Texas Instruments Incorporated (TI) is an America The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America North America is a ...
,
NEC is a Japanese multinational information technology and electronics Electronics comprises the physics, engineering, technology and applications that deal with the emission, flow and control of electrons in vacuum and matter. It uses active d ...
and
Nvidia Nvidia CorporationOfficially written as NVIDIA and stylized in its logo as nVIDIA with the lowercase "n" the same height as the uppercase "VIDIA"; formerly stylized as ''n''VIDIA with a large italicized lowercase "n" on products from the mid 19 ...
. As of November 2010, Renesas and Fresco Logic have passed USB-IF certification. Motherboards for
Intel Intel Corporation is an American multinational corporation A multinational company (MNC) is a corporate A corporation is an organization—usually a group of people or a company A company, abbreviated as co., is a Legal personalit ...

Intel
's
Sandy Bridge Sandy Bridge is the codename A code name, call sign or cryptonym is a code word or name used, sometimes clandestinely, to refer to another name, word, project, or person. Code names are often used for military A military, also known ...
processors have been seen with Asmedia and Etron host controllers as well. On 28 October 2010,
Hewlett-Packard The Hewlett-Packard Company, commonly shortened to Hewlett-Packard ( ) or HP, was an American multinational information technology company headquartered in Palo Alto, California Palo Alto (; Spanish language, Spanish for "tall stick" ...

Hewlett-Packard
released the
HP Envy The HP Envy (stylized as HP ENVY) is a line of consumer-oriented high-end laptop A laptop, laptop computer, or notebook computer is a small, portable personal computer File:Crystal Project computer.png, upright=0.9, An artist's depic ...
17 3D featuring a Renesas USB 3.0 host controller several months before some of their competitors.
AMD Advanced Micro Devices, Inc. (AMD) is an American multinational Multinational may refer to: * Multinational corporation, a corporate organization operating in multiple countries * Multinational force, a military body from multiple countries * M ...

AMD
worked with Renesas to add its USB 3.0 implementation into its chipsets for its 2011 platforms. At CES2011,
Toshiba is a Japanese multinational Multinational may refer to: * Multinational corporation, a corporate organization operating in multiple countries * Multinational force, a military body from multiple countries * Multinational state, a sovereign st ...
unveiled a laptop called " Toshiba Qosmio X500" that included USB 3.0 and Bluetooth 3.0, and
Sony , commonly known as Sony and stylized as SONY, is a Japanese multinational Multinational may refer to: * Multinational corporation, a corporate organization operating in multiple countries * Multinational force, a military body from mult ...

Sony
released a new series of Sony VAIO laptops that would include USB 3.0. As of April 2011, the
Inspiron The Inspiron ( , formerly stylized as inspiron) is a line of consumer-oriented laptop A laptop, laptop computer, or notebook computer is a small, portable personal computer File:Crystal Project computer.png, upright=0.9, An artist's ...
and
Dell XPS Dell XPS ("eXtreme Performance System") is a line of consumer-oriented high-end laptop A laptop or laptop computer is a small, portable personal computer File:Crystal Project computer.png, upright=0.9, An artist's depiction of a 2000s-er ...
series were available with USB 3.0 ports, and, as of May 2012, the
Dell Latitude Latitude is a line of business-oriented laptops manufactured and sold by Dell Technologies aimed at corporate enterprises, healthcare, government, and education markets. The Latitude competes with the ThinkPad series from Lenovo (formerly IBM), ...
laptop series were as well; yet the USB root hosts failed to work at SuperSpeed under Windows 8.


Adding to existing equipment

Additional power for multiple ports on a laptop PC may be derived in the following ways: * Some
ExpressCard ExpressCard, initially called NEWCARD, is an interface to connect peripheral, peripheral devices to a computer, usually a laptop, laptop computer. The ExpressCard technical standard specifies the design of slots built into the computer and of expa ...
-to-USB 3.0 adapters may connect by a cable to an additional USB 2.0 port on the computer, which supplies additional power. * The ExpressCard may have a socket for an external power supply. * If the external device has an appropriate connector, it can be powered by an external power supply. * USB 3.0 port provided by an ExpressCard-to-USB 3.0 adapter may be connected to a separately-powered USB 3.0 hub, with external devices connected to that USB 3.0 hub. On the motherboards of desktop PCs which have
PCI Express PCI Express (Peripheral Component Interconnect Express), officially abbreviated as PCIe or PCI-e, is a high-speed serial Serial may refer to: Arts, entertainment, and media The presentation of works in sequential segments * Serial (literat ...

PCI Express
(PCIe) slots (or the older PCI standard), USB 3.0 support can be added as a PCI Express
expansion card In computing Computing is any goal-oriented activity requiring, benefiting from, or creating computing machinery. It includes the study and experimentation of algorithmic processes and development of both computer hardware , hardware a ...
. In addition to an empty PCIe slot on the motherboard, many "PCI Express to USB 3.0" expansion cards must be connected to a power supply such as a
Molex Molex LLC is a manufacturer of electronic, electrical, and fiber optic connectivity systems. Molex offers over 100,000 products across a variety of industries, including data communications, medical, industrial, automotive and consumer electro ...
adapter or external power supply, in order to power many USB 3.0 devices such as mobile phones, or external hard drives that have no power source other than USB; as of 2011, this is often used to supply two to four USB 3.0 ports with the full 0.9 A (4.5 W) of power that each USB 3.0 port is capable of (while also transmitting data), whereas the PCI Express slot itself cannot supply the required amount of power. If faster connections to storage devices are the reason to consider USB 3.0, an alternative is to use eSATAp, possibly by adding an inexpensive expansion slot bracket that provides an eSATAp port; some external hard disk drives provide both USB (2.0 or 3.0) and eSATAp interfaces. To ensure compatibility between motherboards and peripherals, all USB-certified devices must be approved by the
USB Implementers Forum The USB Implementers Forum (USB-IF) is a nonprofit organization A nonprofit organization (NPO), also known as a non-business entity, not-for-profit organization, or nonprofit institution, is a legal entity organized and operated for a collect ...
(USB-IF). At least one complete end-to-end test system for USB 3.0 designers is available on the market.


Adoption

The USB Promoter Group announced the release of USB 3.0 on November 2008. On 5 January 2010, the
USB-IF The USB Implementers Forum (USB-IF) is a nonprofit organization A nonprofit organization (NPO), also known as a non-business entity, not-for-profit organization, or nonprofit institution, is a legal entity organized and operated for a col ...
announced the first two certified USB 3.0 motherboards, one by ASUS and one by Giga-Byte Technology. Previous announcements included Gigabyte's October 2009 list of seven P55 chipset USB 3.0 motherboards, and an Asus motherboard that was cancelled before production. Commercial controllers were expected to enter into volume production in the first quarter of 2010. On 14 September 2009, Freecom announced a USB 3.0 external hard drive. On 4 January 2010, Seagate announced a small portable HDD bundled with an additional USB 3.0
ExpressCard ExpressCard, initially called NEWCARD, is an interface to connect peripheral, peripheral devices to a computer, usually a laptop, laptop computer. The ExpressCard technical standard specifies the design of slots built into the computer and of expa ...
, targeted for laptops (or desktops with ExpressCard slot addition) at the CES in Las Vegas Nevada. The
Linux kernel mainline The Linux kernel is a free and open-source, Monolithic kernel, monolithic, Modular design, modular, Computer multitasking, multitasking, Unix-like operating system kernel (operating system), kernel. It was conceived and created in 1991 by Linus T ...
contains support for USB 3.0 since version 2.6.31, which was released in September 2009.
FreeBSD FreeBSD is a free and open-source Free and open-source software (FOSS) is software that is both free software and open-source software where anyone is free software license, freely licensed to use, copy, study, and change the software in any ...

FreeBSD
supports USB 3.0 since version 8.2, which was released in February 2011.
Windows 8 Windows 8 is a major release of the Windows NT operating system developed by Microsoft. The product was Software release life cycle#Release to manufacturing (RTM), released to manufacturing on August 1, 2012, and Software release life cycle#Gen ...

Windows 8
was the first Microsoft operating system to offer built in support for USB 3.0. In
Windows 7 Windows 7 is a major release of the Windows NT operating system developed by Microsoft. It was Software release life cycle#Release to manufacturing (RTM), released to manufacturing on July 22, 2009, and became generally available on October 22, ...
support was not included with the initial release of the operating system. However, drivers that enable support for Windows 7 are available through websites of hardware manufacturers.
Intel Intel Corporation is an American multinational corporation A multinational company (MNC) is a corporate A corporation is an organization—usually a group of people or a company A company, abbreviated as co., is a Legal personalit ...
released its first
chipset In a computer system, a chipset is a set of electronic components An electronic component is any basic discrete device or physical entity in an electronic system used to affect electrons or their associated fields. Electronic components ar ...

chipset
with integrated USB 3.0 ports in 2012 with the release of the Panther Point chipset. Some industry analysts have claimed that Intel was slow to integrate USB 3.0 into the chipset, thus slowing mainstream adoption. These delays may be due to problems in the
CMOS Complementary metal–oxide–semiconductor (CMOS, pronounced "see-moss"), also known as complementary-symmetry metal–oxide–semiconductor (COS-MOS), is a type of metal–oxide–semiconductor field-effect transistor The metal–oxide–se ...
manufacturing process, a focus to advance the Nehalem platform, a wait to mature all the 3.0 connections standards (USB 3.0, PCIe 3.0,
SATA 3.0 Serial ATA (SATA, abbreviated from Serial AT Attachment) is a computer bus In computer architecture In computer engineering, computer architecture is a set of rules and methods that describe the functionality, organization, and implemen ...
) before developing a new chipset, or a tactic by Intel to favor its new
Thunderbolt A thunderbolt or lightning bolt is a symbolic representation of lightning when accompanied by a loud thunderclap. In Indo-European mythology, the thunderbolt was identified with the Proto-Indo-European mythology#Sky Father, 'Sky Father'; thi ...
interface. Apple, Inc. announced laptops with USB 3.0 ports on 11 June 2012, nearly four years after USB 3.0 was finalized.
AMD Advanced Micro Devices, Inc. (AMD) is an American multinational Multinational may refer to: * Multinational corporation, a corporate organization operating in multiple countries * Multinational force, a military body from multiple countries * M ...
began supporting USB 3.0 with its Fusion Controller Hubs in 2011.
Samsung Electronics Samsung Electronics Co., Ltd. (; lit. "tristar electronics", sometimes shortened to SEC and stylized as SΛMSUNG) is a South Korean multinational Multinational may refer to: * Multinational corporation, a corporate organization operating in ...
announced support of USB 3.0 with its
ARM In human anatomy The human body is the structure of a human being Humans (''Homo sapiens'') are the most abundant and widespread species In biology, a species is the basic unit of biological classification, classification and ...
-based Exynos 5 Dual platform intended for handheld devices.


Issues


Speed and compatibility

Various early USB 3.0 implementations widely used the
NEC is a Japanese multinational information technology and electronics Electronics comprises the physics, engineering, technology and applications that deal with the emission, flow and control of electrons in vacuum and matter. It uses active d ...
/
Renesas is a Japanese semiconductor A semiconductor material has an electrical conductivity Electrical resistivity (also called specific electrical resistance or volume resistivity) is a fundamental property of a material that measures how str ...
µD72020x family of host controllers, which are known to require a firmware update to function properly with some devices. A factor affecting the speed of USB storage devices (more evident with USB 3.0 devices, but also noticeable with USB 2.0 ones) is that the USB Mass Storage Bulk-Only Transfer (BOT) protocol drivers are generally slower than the
USB Attached SCSI USB Attached SCSI (UAS) or USB Attached SCSI Protocol (UASP) is a computer protocol used to move data to and from USB storage devices such as hard drives (HDDs), solid-state drive A solid-state drive (SSD) is a solid-state storage device t ...
protocol (UAS drivers. On some old (2009–2010) Ibex Peak-based motherboards, the built-in USB 3.0 chipsets are connected by default via a 2.5 
GT/s In computer technology, transfers per second and its more common secondary terms gigatransfers per second (abbreviated as GT/s) and megatransfers per second (MT/s) are informal language that refer to the number of operations transferring data that ...
PCI Express PCI Express (Peripheral Component Interconnect Express), officially abbreviated as PCIe or PCI-e, is a high-speed serial Serial may refer to: Arts, entertainment, and media The presentation of works in sequential segments * Serial (literat ...

PCI Express
lane of the PCH, which then did not provide full PCI Express 2.0 speed (5 GT/s), so it did not provide enough bandwidth even for a single USB 3.0 port. Early versions of such boards (e.g. the
Gigabyte Technology Gigabyte Technology (branded as GIGABYTE or sometimes GIGA-BYTE; formally GIGA-BYTE Technology Co., Ltd.) is a Taiwanese Taiwanese may refer to: * Something from or related to Taiwan (Formosa) * Taiwanese aborigines, the indigenous people of Taiwan ...
P55A-UD4 or P55A-UD6) have a manual switch (in BIOS) that can connect the USB 3.0 chip to the processor (instead of the PCH), which did provide full-speed PCI Express 2.0 connectivity even then, but this meant using fewer PCI Express 2.0 lanes for the graphics card. However, newer boards (e.g. Gigabyte P55A-UD7 or the Asus P7P55D-E Premium) used a
channel bonding In computer networking A computer network is a group of computer A computer is a machine that can be programmed to carry out sequences of arithmetic or logical operations automatically. Modern computers can perform generic sets of ...
technique (in the case of those boards provided by a
PLX PLX, abbreviation of Picatinny Liquid Explosive, is a liquid binary explosive. It is a mixture of 95% nitromethane (NM) along with 5% ethylene diamine (EDA) as a sensitizer. Other amine compounds can be used instead of ethylene diamine, such as tr ...
PEX8608 or PEX8613 PCI Express switch) that combines two PCI Express 2.5 GT/s lanes into a single PCI Express 5 GT/s lane (among other features), thus obtaining the necessary bandwidth from the PCH.


Radio frequency interference

USB 3.0 devices and cables may interfere with wireless devices operating in the 2.4 GHz ISM band. This may result in a drop in throughput or complete loss of response with
Bluetooth Bluetooth is a short-range wireless Wireless communication (or just wireless, when the context allows) is the telecommunication, transfer of information between two or more points that do not use an electrical conductor as a medium by which ...

Bluetooth
and
Wi-Fi Wi-Fi () is a family of wireless network A wireless network is a computer network that uses wireless data connections between network nodes. Wireless networking is a method by which homes, telecommunications networks and business installa ...

Wi-Fi
devices. When manufacturers were unable to resolve the interference issues in time, some mobile devices, such as the Vivo Xplay 3S, had to drop support for USB 3.0 just before they shipped. Various strategies can be applied to resolve the problem, ranging from simple solutions such as increasing the distance of USB 3.0 devices from Wi-Fi routers and Bluetooth devices, to applying additional shielding around internal computer components.


Connectors

A USB 3.0 Standard-A receptacle accepts either a USB 3.0 Standard-A plug or a USB 2.0 Standard-A plug. Conversely, it is possible to plug a USB 3.0 Standard-A plug into a USB 2.0 Standard-A receptacle. This is a principle of backward compatibility. The Standard-A is used for connecting to a computer port, at the host side. A USB 3.0 Standard-B receptacle accepts either a USB 3.0 Standard-B plug or a USB 2.0 Standard-B plug. Backward compatibility applies to connecting a USB 2.0 Standard-B plug into a USB 3.0 Standard-B receptacle. However, it is not possible to plug a USB 3.0 Standard-B plug into a USB 2.0 Standard-B receptacle, due to a physically larger connector. The Standard-B is used at the device side. Since USB 2.0 and USB 3.0 ports may coexist on the same machine and they look similar, the USB 3.0 specification recommends that the Standard-A USB 3.0 receptacle have a blue insert (
Pantone Pantone LLC is a limited liability company A limited liability company (LLC) is the US-specific form of a private limited company A private limited company is any type of business entity in Privately held company, "private" ownership ...
300C color). The same color-coding applies to the USB 3.0 Standard-A plug. USB 3.0 also introduced a new Micro-B cable plug, which consists of a standard USB 1.x/2.0 Micro-B cable plug, with an additional 5-pin plug "stacked" inside it. That way, the USB 3.0 Micro-B host connector preserved its backward compatibility with the USB 1.x/2.0 Micro-B cable plugs, allowing devices with USB 3.0 Micro-B ports to run at USB 2.0 speeds on USB 2.0 Micro-B cables. However, it is not possible to plug a USB 3.0 Micro-B plug into a USB 2.0 Micro-B receptacle, due to a physically larger connector.


Pinouts

The connector has the same physical configuration as its predecessor but with five more pins. The VBUS, D−, D+, and GND pins are required for USB 2.0 communication. The additional USB 3.0 pins are two differential pairs and one ground (GND_DRAIN). The two additional differential pairs are for SuperSpeed data transfer; they are used for full duplex SuperSpeed signaling. The GND_DRAIN pin is for drain wire termination and to control EMI and maintain signal integrity.


Backward compatibility

USB 3.0 and USB 2.0 (or earlier) Type-A plugs and receptacles are designed to interoperate. USB 3.0 Type-B receptacles, such as those found on peripheral devices, are larger than in USB 2.0 (or earlier versions), and accept both the larger USB 3.0 Type-B plug and the smaller USB 2.0 (or earlier) Type-B plug. USB 3.0 Type B plugs are larger than USB 2.0 (or earlier) Type-B plugs; therefore, USB 3.0 Type-B plugs cannot be inserted into USB 2.0 (or earlier) Type-B receptacles. Micro USB 3.0 (Micro-B) plug and receptacle are intended primarily for small portable devices such as smartphones, digital cameras and GPS devices. The Micro USB 3.0 receptacle is backward compatible with the Micro USB 2.0 plug. A receptacle for eSATAp, which is an eSATA/USB combo, is designed to accept USB Type-A plugs from USB 2.0 (or earlier), so it also accepts USB 3.0 Type-A plugs.


USB 3.1

In January 2013 the USB group announced plans to update USB 3.0 to 10 Gbit/s (1250 MB/s). The group ended up creating a new USB specification, USB 3.1, which was released on 31 July 2013, replacing the USB 3.0 standard. The USB 3.1 specification takes over the existing USB 3.0's ''SuperSpeed USB'' transfer rate, also referred to as ''USB 3.1 Gen 1'', and introduces a faster transfer rate called ''SuperSpeed USB 10 
Gbps In telecommunications Telecommunication is the transmission of information by various types of technologies over wire, radio, Optical system, optical, or other Electromagnetism, electromagnetic systems. It has its origin in the desire of hu ...
'', referred to as ''USB 3.1 Gen 2,'' putting it on par with a single first-generation
Thunderbolt A thunderbolt or lightning bolt is a symbolic representation of lightning when accompanied by a loud thunderclap. In Indo-European mythology, the thunderbolt was identified with the Proto-Indo-European mythology#Sky Father, 'Sky Father'; thi ...
channel. The new mode's logo features a caption stylized as ''SUPERSPEED+''. The USB 3.1 Gen 2 standard also reduces line encoding overhead to just 3% by changing the encoding scheme to 128b/132b, with effective data rate of 1,212 MB/s. The first USB 3.1 Gen 2 implementation demonstrated real-world transfer speeds of 7.2 Gbit/s. The USB 3.1 standard is backward compatible with USB 3.0 and USB 2.0. It defines the following transfer modes: * USB 3.1 Gen 1 – SuperSpeed, 5 Gbit/s data signaling rate over 1 lane using 8b/10b encoding (effective 500 MB/s); the same as USB 3.0 * USB 3.1 Gen 2 – SuperSpeed+, new 10 Gbit/s data rate over 1 lane using 128b/132b encoding (effective 1212 MB/s) The nominal data rate in bytes accounts for bit-encoding overhead. The physical SuperSpeed bit rate is 5 Gbit/s. Since transmission of every byte takes 10 bit times, the raw data overhead is 20%, so the byte rate is 500 MB/s, not 625. Similarly, at SS+ rate the encoding is 128b/132b, so transmission of 16 bytes physically takes 16.5 bytes, or 3% overhead. Therefore, the byte-rate at SS+ is 128/132 * 10 Gbit/s = 9.697 GBit/s = 1212 MB/s. In reality the SS bus has some additional service overhead (link management, protocol response, host latencies), so the best-case achievable data rates are about 10% smaller. This rebranding of USB 3.0 as "USB 3.1 Gen 1" has allowed manufacturers to advertise products with transfer rates of only 5 Gbit/s as "USB 3.1," omitting the generation.


USB 3.2

On 25 July 2017, a press release from the USB 3.0 Promoter Group detailed a pending update to the specification, defining the doubling of bandwidth for existing USB-C cables. Under the USB 3.2 specification, released 22 September 2017, existing SuperSpeed certified USB-C 3.1 Gen 1 cables will be able to operate at 10 Gbit/s (up from 5 Gbit/s), and SuperSpeed+ certified USB-C 3.1 Gen 2 cables will be able to operate at 20 Gbit/s (up from 10 Gbit/s). The increase in bandwidth is a result of multi-lane operation over existing wires that were intended for flip-flop capabilities of the USB-C connector. The USB 3.2 standard is backward compatible with USB 3.1/3.0 and USB 2.0. It defines the following transfer modes: * USB 3.2 Gen 1 – SuperSpeed, 5 gigabit per second (Gbit/s) data signaling rate over 1 lane using 8b/10b encoding (effective 0.500 GB/s) , the same as USB 3.1 Gen 1 and USB 3.0. * USB 3.2 Gen 2 – SuperSpeed+, 10 gigabit per second (Gbit/s) data rate over 1 lane using 128b/132b encoding (effective 1.212 GB/s), the same as USB 3.1 Gen 2. * USB 3.2 Gen 1×2 – SuperSpeed+, new 10 gigabit per second (Gbit/s) data rate over 2 lanes using 8b/10b encoding (effective 1 GB/s). * USB 3.2 Gen 2×2 – SuperSpeed+, new 20 gigabit per second (Gbit/s) data rate over 2 lanes using 128b/132b encoding (effective 2.424 GB/s). As with the previous version, the same considerations around encoding and effective data rates apply. Although both Gen 1×2 and Gen 2×1 signal at 10 Gbit/s, Gen 1×2 uses the older, less efficient line coding which results in a somewhat lower effective speed. In May 2018,
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demonstrated the first USB 3.2 Gen 2×2 connection, where a Windows PC was connected to a storage device, reaching an average speed of 1600 MB/s. USB 3.2 is supported with the default Windows 10 USB drivers and in Linux kernels 4.18 and onwards. In February 2019, USB-IF simplified the marketing guidelines and required the SuperSpeed trident logos to include maximum transfer speed.


See also

*
USB4 USB4 is a USB Universal Serial Bus (USB) is an industry standard ''Industry Standard'' is a 1982 album by Dixie Dregs, The Dregs. It is their only album featuring vocals (by Alex Ligertwood of Santana (band), Santana and Patrick Simmons o ...
*
Computer bus In computer architecture In computer engineering, computer architecture is a set of rules and methods that describe the functionality, organization, and implementation of computer A computer is a machine that can be programmed to carry ...
* Extensible Host Controller Interface (XHCI) * *
Mobile High-Definition Link Mobile High-Definition Link (MHL) is an Technical standard, industry standard for a mobile audio/video interface that allows the connection of smartphones, tablets, and other portable consumer electronics devices to high-definition televisions (H ...
*


References


External links

* * CES 2014 report of a laptop docking port using a single USB 3.1 port to supply power, video and USB peripherals {{Basic computer components #3.0 Computer-related introductions in 2008