Initially developed in the s as a standardized method of connecting computers with keyboards, displays, and other peripherals, Universal Serial Bus (USB) cables have transformed how electronic devices exchange power and data. USB simplifies and streamlines connections between a wide range of devices and is a necessary component of many tools we use daily.
You can find more information on our web, so please take a look.
Today, there are several USB connector types, each of which is further classified according to its power specifications. In this guide, we&#;ll discuss the most common types of USB connectors and the key selection considerations to help you identify the right product for your needs.
Modern USB cables facilitate data communication and power delivery and are significantly faster than previous generations. However, they also come in multiple connection types, which are largely incompatible with one another. This makes it essential to identify the right USB type for your device&#;s port. Below, you can learn more about the different types of USB connectors.
Widely regarded as the standard connector type, USB Type-A connectors are very common. They feature a flat, rectangular interface that joins directly to host devices, held in place using friction. A-Type connectors are durable enough to establish continuous connections but also user-friendly enough to be easily connected and disconnected. In most cases, IT peripherals have a USB Type-A connector that plugs into a PC. USB A-Type is also available in micro variations.
USB Type-B connectors have traditionally been used with printer cables but are now more commonly used in cell phones and other peripheral devices like external hard drives. They feature a square interface and are available in several types:
Developed in the early s, the USB mini-B features a slim profile and a snug fit. While it was initially used in early smartphones, digital cameras, and GPS navigation systems, it is less popular today due to the rise of micro USB technology.
As a very small 5-pin connector, the micro USB connector type is commonly used with small electronics like smartphones, game controllers, and power banks. USB micro-B is also widely used in Android smartphones that lack a USB-C receptacle.
The newest type of connector, USB C-Type provides a one-size-fits-all solution for replacing older, larger USBs. It features a reversible, symmetrical interface and a sleek, slim design. It can also be adapted to support legacy connectors.
In addition to being categorized by type, USBs are further classified according to their power specifications. Each new version offers increased bandwidth and compatibility with an even broader range of devices and applications.
While now obsolete, the USB 1.1 was the first widely used consumer USB. It enabled a maximum bandwidth of 12 Mpbs and was compatible with basic devices, like computer mice and keyboards.
Also known as the high-speed USB, version 2.0 improved the bandwidth to 480 Mbps. This upgrade allows it to be used for higher bandwidth devices, such as transfer cables, adapters, and mass storage equipment. USB 2.0 also features backward compatibility with USB 1.1 devices.
Referred to as the SuperSpeed USB, 3.0 offers bandwidth improvements, jumping to a maximum of 4.8 Gbps. It also offers backward compatibility with legacy devices.
USB 3.1 can be identified by the switch to blue connectors. These products are capable of transfer speeds up to 5 Gbps and have been incorporated into products like the Apple MacBook.
Updates have enabled these USB-C connectors to achieve 20 Gpbs.
Initially launched in with a maximum data transfer rate of 40 Gbps, USB 4.0 connectors output a power of 100 watts. These USB-C cables feature the SuperSpeed logo, SS40, which stands for SuperSpeed 40 Gbps.
The latest version of this specification, launched in , features the highest-ever data transfer rate: 120 Gbps. Since this version is still very new, these USB-C cables may not be easily purchased yet.
With each USB advancement, devices achieve enhanced power delivery standards and improved communication capabilities.
USB 1.1USB 2.0USB 3.0USB 3.1 Also Known AsUSB 3.1 Gen 1USB 3.1 Gen 2 Release Date Speed/Transfer Full SpeedAs discussed earlier, newer developments in USBs offer a simple and comprehensive solution for data transfer and power supply for any device. A USB Type-C connector fits into one multi-use port to charge multiple devices simultaneously. It also offers backward compatibility to support previous USB standards (2.0, 3.0, and 3.1).
Type-C 3.1 features a reversible cable that enables two-way data and power transfer, along with 10 Gbps bandwidth and power up to 20 V at 5 Amps, or a total of 100 W. This is enough power to charge a laptop or operate a 4K monitor. Since this technology is nonproprietary, USB Type-C connectors are quickly becoming the new standard for many operating systems. For example, Intel&#;s Thunderbolt switched to USB Type-C ports while remaining compatible with USB 3.1. Apple MacBooks also now feature Type-C ports.
Selecting the right USB cable requires consideration of several factors, such as:
Consolidated Electronic Wire & Cable has over 100 years of experience delivering high-quality cable solutions. In addition to offering an extensive collection of standard USB connectors, we also create custom USB-C cables according to diverse data transfer and charging needs. Contact our team to learn more.
Watch the video!
Below, you can explore some of the most common questions our team is asked about USB cables. If you&#;re looking for information not listed here, don&#;t hesitate to get in touch with us&#;we&#;re happy to help.
In many cases, yes. Both USB-A and USB-C cables support data transfer and charging functions. However, some USB-B cables might only offer data transfer capabilities.
Verify this information by checking the cable packaging or manufacturer&#;s information. However, if this isn&#;t an option, USB 2.0 cables typically have white or black plastic inside the connector. USB 3.0 cables and later versions feature blue plastic.
When you get USB cables from us, you&#;ll get:
"SuperSpeed" redirects here. For other uses, see Super Speed
A deprecated
[
2]
SuperSpeed USB 5 Gbit/s packaging logoUniversal Serial Bus 3.0 (USB 3.0), marketed as SuperSpeed USB, is the third major version of the Universal Serial Bus (USB) standard for interfacing computers and electronic devices. It was released in November . The USB 3.0 specification defined a new architecture and protocol, named SuperSpeed, which included a new lane for providing full-duplex data transfers that physically required five additional wires and pins, while also adding a new signal coding scheme (8b/10b symbols, 5 Gbps; also known later as Gen 1), and preserving the USB 2.0 architecture and protocols and therefore keeping the original four pins and wires for the USB 2.0 backward-compatibility, resulting in nine wires in total and nine or ten pins at connector interfaces (ID-pin is not wired). The new transfer rate, marketed as SuperSpeed USB (SS), can transfer signals at up to 5 Gbit/s with raw data rate of 500 MB/s after encoding overhead, which is about 10 times faster than High-Speed (maximum for USB 2.0 standard). USB 3.0 Type-A and B connectors are usually blue, to distinguish them from USB 2.0 connectors, as recommended by the specification,[3] and by the initials SS.[4]
USB 3.1, released in July , is the successor specification that fully replaces the USB 3.0 specification. USB 3.1 preserves the existing SuperSpeed USB architecture and protocol with its operation mode (8b/10b symbols, 5 Gbps), giving it the label USB 3.1 Gen 1.[5][6] USB 3.1 introduced an Enhanced SuperSpeed System &#; while preserving and incorporating the SuperSpeed architecture and protocol (aka SuperSpeed USB) &#; with an additional SuperSpeedPlus architecture adding and providing a new coding schema (128b/132b symbols) and protocol named SuperSpeedPlus (aka SuperSpeedPlus USB, sometimes marketed as SuperSpeed+ or SS+) while defining a new transfer mode called USB 3.1 Gen 2[5] with a signal speed of 10 Gbit/s and a raw data rate of MB/s over existing Type-A, Type-B, and USB-C connections, more than twice the rate of USB 3.0 (aka Gen 1).[7][8] Backward-compatibility is still given by the parallel USB 2.0 implementation. USB 3.1 Gen 2 Type-A and Type-B connectors are usually teal-colored.
USB 3.2, released in September , fully replaces the USB 3.1 specification. The USB 3.2 specification added a second lane to the Enhanced SuperSpeed System besides other enhancements, so that SuperSpeedPlus USB implements the Gen 2x1 (formerly known as USB 3.1 Gen 2), and the two new Gen 1x2 and Gen 2x2 operation modes while operating on two lanes. The SuperSpeed architecture and protocol (aka SuperSpeed USB) still implements the one-lane Gen 1x1 (formerly known as USB 3.1 Gen 1) operation mode. Therefore, two-lane operations, namely USB 3.2 Gen 1x2 (10 Gbit/s with raw data rate of 1 GB/s after encoding overhead) and USB 3.2 Gen 2x2 (20 Gbit/s, 2.422 GB/s), are only possible with Full-Featured USB Type-C Fabrics (24 pins). As of , USB 3.2 Gen 1x2 and Gen 2x2 are not implemented on many products yet; Intel, however, starts to include them in its LGA Rocket Lake chipsets (500 series) in January and AMD in its LGA AM5 chipsets in September , but Apple never provided them. On the other hand, USB 3.2 Gen 1x1 (5 Gbit/s) and Gen 2x1 (10 Gbit/s) implementations have become quite common. Again, backward-compatibility is given by the parallel USB 2.0 implementation.
[
edit
]
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 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:
[
9]
USB 3.0 has transmission speeds of up to 5 Gbit/s or Mbit/s, about ten times faster than USB 2.0 (0.48 Gbit/s) even without considering that USB 3.0 is full duplex whereas USB 2.0 is half duplex. This gives USB 3.0 a potential total bidirectional bandwidth twenty times greater than USB 2.0.[10] Considering flow control, packet framing and protocol overhead, applications can expect 450 MB/s of bandwidth.[11]
[
edit
]
Front view of a Standard-A USB 3.0 connector, showing its front row of four pins for the USB 1.x/2.0 backward compatibility, and a second row of five pins for the later (but out-of-date) USB 3.0 connectivity. The plastic insert is in the USB 3.0 standard blue color, Pantone 300C.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. 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.
[
edit
]
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, it sends an Endpoint Ready (ERDY) to the host which then reschedules the transaction.
The use of unicast and the limited number 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.
USB 3.0 uses a spread-spectrum clock varying by up to ppm at 33 KHz to reduce EMI. As a result, the receiver needs to continually "chase" the clock to recover the data. Clock recovery is helped by the 8b/10b encoding and other designs.[12]
[
edit
]
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.[13]
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; this helps prevent transmissions from generating electromagnetic interference (EMI).[7] Scrambling is implemented using a free-running linear feedback shift register (LFSR). The LFSR is reset whenever a COM symbol is sent or received.[13]
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 3 meters (10 ft).[14]
[
edit
]
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.[13]:&#;section 9.2.5.1 Power Budgeting&#;
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 for charging the host device up to 100 W.[15]
[
edit
]
Starting with the USB 3.2 specification, USB-IF introduced a new naming scheme.[16] To help companies with branding of the different operation modes, USB-IF recommended branding the 5, 10, and 20 Gbit/s capabilities as SuperSpeed USB 5Gbps, SuperSpeed USB 10 Gbps, and SuperSpeed USB 20 Gbps, respectively.[17]
In , they were replaced again,[18] removing "SuperSpeed", with USB 5Gbps, USB 10Gbps, and USB 20Gbps. With new Packaging and Port logos.[19]
[
edit
]
Internal circuitboard and connectors of a USB 3.0 four-port hub, using a VIA Technologies chipsetThe USB 3.0 Promoter Group announced on 17 November that the specification of version 3.0 had been completed and had made the transition to the USB Implementers Forum (USB-IF), the managing body of USB specifications.[20] 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 , while the first certified USB 3.0 consumer products were announced on 5 January , at the Las Vegas Consumer Electronics Show (CES), including two motherboards by Asus and Gigabyte Technology.[21][22]
Manufacturers of USB 3.0 host controllers include, but are not limited to, Renesas Electronics, Fresco Logic, ASMedia, Etron, VIA Technologies, Texas Instruments, NEC and Nvidia. As of November , Renesas and Fresco Logic[23] have passed USB-IF certification. Motherboards for Intel's Sandy Bridge processors have been seen with Asmedia and Etron host controllers as well. On 28 October , Hewlett-Packard released the HP Envy 17 3D featuring a Renesas USB 3.0 host controller several months before some of their competitors. AMD worked with Renesas to add its USB 3.0 implementation into its chipsets for its platforms.[needs update] At CES, Toshiba unveiled a laptop called "Qosmio X500" that included USB 3.0 and Bluetooth 3.0, and Sony released a new series of Sony VAIO laptops that would include USB 3.0. As of April , the Inspiron and Dell XPS series were available with USB 3.0 ports, and, as of May , the Dell Latitude laptop series were as well; yet the USB root hosts failed to work at SuperSpeed under Windows 8.
[
edit
]
A USB 3.0 controller in form of a PCI Express expansion card Side connectors on a laptop computer. Left to right: USB 3.0 host, VGA connector, DisplayPort connector, USB 2.0 host. Note the five additional pins on the underside of the tongue of the USB 3.0 port.Additional power for multiple ports on a laptop PC may be obtained in the following ways:
On the motherboards of desktop PCs which have PCI Express (PCIe) slots (or the older PCI standard), USB 3.0 support can be added as a PCI Express expansion card. 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 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 , 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.[22] To ensure compatibility between motherboards and peripherals, all USB-certified devices must be approved by the USB Implementers Forum (USB-IF). At least one complete end-to-end test system for USB 3.0 designers is available on the market.[24]
[
edit
]
The USB Promoter Group announced the release of USB 3.0 in November . On 5 January , the USB-IF announced the first two certified USB 3.0 motherboards, one by ASUS and one by Giga-Byte Technology.[22][25] Previous announcements included Gigabyte's October list of seven P55 chipset USB 3.0 motherboards,[26] and an Asus motherboard that was cancelled before production.[27]
Commercial controllers were expected to enter into volume production in the first quarter of .[28] On 14 September , Freecom announced a USB 3.0 external hard drive.[29] On 4 January , Seagate announced a small portable HDD bundled with an additional USB 3.0 ExpressCard, targeted for laptops (or desktops with ExpressCard slot addition) at the CES in Las Vegas Nevada.[30][31]
If you are looking for more details, kindly visit AIKE Electronics.
The Linux kernel mainline contains support for USB 3.0 since version 2.6.31, which was released in September .[32][33][34]
FreeBSD supports USB 3.0 since version 8.2, which was released in February .[35]
Windows 8 was the first Microsoft operating system to offer built in support for USB 3.0.[36] In Windows 7 support was not included with the initial release of the operating system.[37] However, drivers that enable support for Windows 7 are available through websites of hardware manufacturers.
Intel released its first chipset with integrated USB 3.0 ports in 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.[38] These delays may be due to problems in the CMOS manufacturing process,[39] a focus to advance the Nehalem platform,[40] a wait to mature all the 3.0 connections standards (USB 3.0, PCIe 3.0, SATA 3.0) before developing a new chipset,[41][42] or a tactic by Intel to favor its new Thunderbolt interface.[43] Apple, Inc. announced laptops with USB 3.0 ports on 11 June , nearly four years after USB 3.0 was finalized.
AMD began supporting USB 3.0 with its Fusion Controller Hubs in . Samsung Electronics announced support of USB 3.0 with its ARM-based Exynos 5 Dual platform intended for handheld devices.
[
edit
]
[
edit
]
Various early USB 3.0 implementations widely used the NEC/Renesas μDx family of host controllers,[44] which are known to require a firmware update to function properly with some devices.[45][46][47]
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 protocol (UAS[P]) drivers.[48][49][50][51]
On some old (&#;) Ibex Peak-based motherboards, the built-in USB 3.0 chipsets are connected by default via a 2.5 GT/s 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 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 technique (in the case of those boards provided by a PLX PEX or PEX 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.[52][53][54]
Radio frequency interference[
edit
]
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 and Wi-Fi devices.[55] 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.[56] 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 and Bluetooth devices, to applying additional shielding around internal computer components.[57]
Connectors[
edit
]
USB 3.0 Standard-A receptacle (top, in the blue color " Pantone 300C"), Standard-B plug (middle), and Micro-B plug (bottom)
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 plug 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 the physically larger connector. The Standard-B plug 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 300C color). The same color-coding applies to the USB 3.0 Standard-A plug.[13]:&#;sections 3.1.1.1 and 5.3.1.3&#;
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" beside it. That way, the USB 3.0 Micro-B host receptacle preserves its backward compatibility with the USB 1.x/2.0 Micro-B cable plug, 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 the physically larger connector.
Pinouts[
edit
]
USB 3.0 Standard-A plug (top) and receptacle (bottom), with annotated pins
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 five 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.
USB 3.0 connector pinouts[
58]
Pin Color Signal name Description A connector B connector Shell &#; Shield Metal housing 1 Red VBUS Power 2 White D&#; USB 2.0 differential pair 3 Green D+ 4 Black GND Ground for power return 5 Blue StdA_SSRX&#; StdB_SSTX&#; SuperSpeed receiver differential pair 6 Yellow StdA_SSRX+ StdB_SSTX+ 7 &#; GND_DRAIN Ground for signal return 8 Purple StdA_SSTX&#; StdB_SSRX&#; SuperSpeed transmitter differential pair 9 Orange StdA_SSTX+ StdB_SSRX+ The USB 3.0 Powered-B connector has two additional pins for power and ground supplied to the device.[
59]
10 &#; DPWR Power provided to device (Powered-B only) 11 DGND Ground for DPWR return (Powered-B only) Backward compatibility[
edit
]
USB Micro-B USB 2.0 vs USB Micro-B SuperSpeed (USB 3.0) (Note that &#;Macro-B&#; in the image is an error. No such term has ever existed for USB.)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[
edit
]
A deprecated[
2]
SuperSpeed+ USB 10 Gbit/s packaging logoIn January the USB group announced plans to update USB 3.0 to 10 Gbit/s ( MB/s).[60] The group ended up creating a new USB specification, USB 3.1, which was released on 31 July ,[61] replacing the USB 3.0 standard. The USB 3.1 specification takes over the existing USB 3.0's SuperSpeed USB transfer rate, now referred to as USB 3.1 Gen 1, and introduces a faster transfer rate called SuperSpeed USB 10 Gbps, corresponding to operation mode USB 3.1 Gen 2,[62] putting it on par with a single first-generation Thunderbolt channel. The new mode's logo features a caption stylized as SUPERSPEED+;[63] this refers to the updated SuperSpeedPlus protocol. The USB 3.1 Gen 2 mode also reduces line encoding overhead to just 3% by changing the encoding scheme to 128b/132b, with raw data rate of 1,212 MB/s.[64] The first USB 3.1 Gen 2 implementation demonstrated real-world transfer speeds of 7.2 Gbit/s.[65]
The USB 3.1 specification includes the USB 2.0 specification while fully preserving its dedicated physical layer, architecture, and protocol in parallel. USB 3.1 specification defines the following operation modes:
The nominal data rate in bytes accounts for bit-encoding overhead. The physical SuperSpeed signaling bit rate is 5 Gbit/s. Since transmission of every byte takes 10 bit times, the raw data overhead is 20%, so the raw byte rate is 500 MB/s, not 625. Similarly, for Gen 2 link the encoding is 128b/132b, so transmission of 16 bytes physically takes 16.5 bytes, or 3% overhead. Therefore, the new raw byte-rate is 128/132 * 10 Gbit/s = 9.697 Gbit/s = MB/s. In reality any operation mode has additional link management and protocol overhead, so the best-case achievable data rates for the Gen 2 operation mode are of roughly below 800 MB/s for reading bulk transfers only.[66][11]
The re-specification of USB 3.0 as "USB 3.1 Gen 1" was misused by some manufacturers to advertise products with signaling rates of only 5 Gbit/s as "USB 3.1" by omitting the defining generation.[67]
USB 3.2[
edit
]
A deprecated[
2]
SuperSpeed+ USB 20 Gbit/s packaging logo USB 20Gbps port logoOn 25 July , a press release from the USB 3.0 Promoter Group detailed a pending update to the USB Type-C specification, defining the doubling of bandwidth for existing USB-C cables. Under the USB 3.2 specification, released 22 September ,[11] 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.[68][69]
The USB 3.2 standard includes the USB 2.0 specification with four dedicated wires on the physical layer. The Enhanced SuperSpeed System encompasses both, but separated &#; and in parallel to the USB 2.0 implementation:[70]
[
63]
10 Gbit/s signaling rate over 1 lane using 128b/132b encoding (raw data rate: MB/s); replaces USB 3.1 Gen 2.As with the previous version, the same considerations around encoding and raw data rates apply. Although both Gen 1x2 and Gen 2(x1) signal at 10 Gbit/s, Gen 1x2 uses the older, less efficient 8b/10b line coding which results in a lower raw data rate compared with Gen 2(x1), though both using the newer SuperSpeedPlus protocol.[70]
In May , Synopsys demonstrated the first USB 3.2 Gen 2x2 operation mode, where a Windows PC was connected to a storage device, reaching an average data rate of MB/s for reading bulk transmissions,[71][72] which is 66% of its raw throughput.
USB 3.2 is supported with the default Windows 10 USB drivers and in Linux kernels 4.18 and onwards.[71][72][73]
In February , USB-IF simplified the marketing guidelines by excluding Gen 1x2 mode and required the SuperSpeed trident logos to include maximum transfer speed.[74][75]
Two-lane operation (USB 3.2 Gen 1x2, USB 3.2 Gen 2x2) is only possible with Full-Featured USB-C Fabrics.[76]
[
edit
]
[
edit
]
If you are looking for more details, kindly visit USB3.0 Connector manufacturer.