Which flash drive is better 2.0 or 3.0. What is the difference between USB2.0 and USB3.0


There are many varieties and modifications of even the simplest and most affordable electronic equipment, such as, for example.

Not many people paid attention, but even they have two common modifications - 3.0 and 2.0.

In this article we will look at USB 2.0 and USB 3.0, discuss their differences and speed.

Features of the concept

There are well-known rectangular posts for connecting USB format. You need to connect the appropriate cables, memory cards, etc. to them.

Physically, all these ports are the same (in size and appearance), you can connect any device of the appropriate format to them.

However, the ports differ in configuration, and there are two types: USB 2.0, and USB 3.0. As is clear from the designation, version 3.0 is newer and more modern than 2.0. It has the best performance characteristics in many respects. However, these formats are conditionally compatible, that is, selecting appropriate devices will not present any special problems.

However, these configurations have quite different performance characteristics, and it is them that will be discussed in this material.

Story

To fully understand the differences between these two versions, you need to understand what USB is, how such a port works, and how it is fundamentally different from other types.

USB is an abbreviation for the English phrase “universal serial bus”.

The main positive difference between this format and all others is that it can be used to transmit absolutely any data and type of information; any device can be connected to this port.

It is these features that make this type of slot so popular and widespread for many years. During this time, many of its varieties and configurations appeared, the main difference between which is.

Old PCs were not distinguished by high versatility of connections - they had a wide variety of ports for certain purposes, this or that equipment. But since 1994, development has been underway on a multifunctional universal port, which eventually became USB. The first version of a device similar to the modern one appeared in 1996 and was designated 1.0.

Its speed was minimal and barely reached 1.5 Mbit/s. And in 2000, the next version appeared - 2.0, and it had a more applicable speed of 480 Mbit/s.

This speed already made it possible to really use the port to its fullest, since it finally became possible to connect simple equipment to the port, like .

Version 3.0, which is the newest and most modern at the moment, was released in 2008. It theoretically allows you to develop very high speeds, up to 5 Gb/sec. This speed allows you to connect not only simple equipment and memory cards to the port, but also more or less complex and powerful devices, for example.

The development of a new version of the port was actively sponsored by many global brands, leading manufacturers in the computer and microelectronics field.

They were interested in introducing a standardized universal connector that could handle even complex devices, as this approach would significantly simplify production and help cover a larger market.

Main differences

How do the types of these ports differ from each other?

There are several main differences:

  • Visually distinguishing all three versions from each other is very simple - version 1.0 is missing on all computers released after 2009, version 2.0 ports are uncolored (white), and version 3.0 ports are blue, so you can identify them before purchasing the device, without looking at the technical documentation;
  • Transmission speed- the main functional difference between these devices. It becomes obvious when using them, and it is precisely this that is the reason that the same device in different ports can operate at different speeds. Although the transfer speed of version 3.0 is actually much lower than the stated maximum of 5 Gb/s, it is still much higher than that of the second version;
  • There is also an operational difference and it lies in the current strength. If in the old version it was 500 mA, then in the new one it is almost 900 mA. Thanks to this feature, such a port can supply electricity to several powerful devices when using a splitter;
  • From the point of view of the cable itself, there are also some differences. If the old version had only 4 wires under the braid, then the new one has 8 of them, which speeds up the work. But it is also for this reason that the cable of the new version is thicker. There are also negative aspects to this, since such a cable arrangement limited its maximum possible length to 5 meters and significantly increased its cost;
  • No older version of the Windows operating system, including XP, will work with the new version of the port., since it is not technically suitable for this. All cables and ports of version 3.0 will still work in version 2.0 when connected to a device with such an old operating system.

Thus, although this version has a number of undeniable advantages, like a newer one, it also has serious disadvantages.

The limited cable length can be very inconvenient for many users, especially when organizing workspaces.

Compatibility

Are versions 2.0 and 3.0 compatible? Is it possible to connect a cable from one version to the port of another?

This is technically possible - the device will work properly, since the ports are physically compatible. However, there will always be significant changes in functioning.

Namely, with this combination, USB will always work according to the parameters of the older version, that is, in this case, in format 2.0.

The fact is that while the new version is adapted for a temporary “rollback” to the old one, the old one simply does not have the technical and design capabilities to work in the 3.0 format, as is clear from what is written above.

Thus, these versions can be called conditionally compatible.

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In fact, the main disadvantage of the new version of the devices is the price, because they are a little more expensive.

In addition, due to the shorter cable length, it may be necessary to use adapters and adapters, which further increases the cost.

On the other hand, such expenses will not be weekly - most often they are done once every few years, but they guarantee stable and fast operation of the devices throughout the entire period of operation.

Although the USB 3.0 interface is becoming more and more popular, not all modern motherboards can boast of having a corresponding controller (and support from chipsets is only expected in the future - fortunately, not far away). What can we say about the numerous systems assembled on the basis of components from previous years - the good old USB 2.0 reigns supreme there.

Of course, the new standard will eventually displace the honored veteran of the industry (it’s no joke - it’s been in service for a good decade, the oldest old-fashioned commonly used interfaces are only the PCI bus and PS/2 connectors, and even those can’t always be found on modern motherboards!). But is it worth running ahead of the locomotive, preparing the periphery in advance for the new standard? How good is the claimed compatibility between USB 2.0 and USB 3.0 devices and controllers? Is there a performance difference between USB 2.0 and USB 3.0 drives when running legacy USB?

To answer these questions, we took two USB drives available to us for the USB 3.0 interface and a couple of flash drives for USB 2.0. The basis for comparison was the Gigabyte GA-Z68X-UD3P-B3 motherboard, which offers the user both USB 2.0 ports of the Intel Z68 chipset and a USB 3.0 controller manufactured by EtronTech.

Test participants

The four drives were selected quite simply. We used both key fobs with a USB 3.0 interface that we had from two different “royal” companies: Kingston and Kingmax. For greater clarity, we took another couple of USB 2.0 drives from two opposite poles of the market: a cheap and slow ADATA flash drive in the mass segment and an expensive, fast and protected from any environmental troubles Corsair Survivor GTR drive.

Let us now devote a few words to each of the drives participating in the comparison, especially since the alphabetical order ideally arranges our four according to the performance declared by the manufacturers.

ADATA C905

Volume: 32 GB
Interface: USB 2.0
Manufacturer's stated sequential read speed: 30 MB/s
Manufacturer's stated sequential write speed: 8 MB/s
Dimensions: 18.7 x 10.7 x 61.8 mm
Weight: 13 g

The most ordinary inexpensive flash drive (about 1,400 rubles for 32 GB), which stands out from most analogues except for its nice matte aluminum case.

The drive is quite convenient to use (compact size, well-fixed cap, minimal heating during use), but even the characteristics declared by the manufacturer (which in practice it falls somewhat short of) do not allow one to hope for speed records and set the owner up in advance to practice patience.

Corsair Survivor GTR



Volume: 32 GB
Interface: USB 2.0
Manufacturer's stated sequential read speed: 34 MB/s
Manufacturer's stated sequential write speed: 28 MB/s
Dimensions: 22 x 22 x 113 mm
Weight: 54 g

The second of the tested drives boasts almost absolute protection from environmental influences. A case made of durable aluminum alloy with threaded connections and rubber gaskets is able to protect the flash drive from impacts with acceleration up to 1500 g, and from immersion in water to a depth of 200 meters, and from vibration.

The speed indicators are no less impressive (at least compared to most drives with a USB 2.0 interface), and heating during operation is minimal. A real high-end product, but at an appropriate price, significantly higher than the cost of most drives of similar capacity known to us - even models with USB 3.0 support.

The dimensions of the drive are very large: it is the longest in our quartet, and the diameter of the protective case successfully competes with the cross-section of a very plump Kingston model for USB 3.0.

Kingmax ED-01


Volume: 64 GB
Interface: USB 3.0
Manufacturer's stated sequential read speed: 66 MB/s
Manufacturer's stated sequential write speed: 41 MB/s
Dimensions: 20 x 9 x 74.5 mm
Weight: 10.5 g


This drive has dimensions that are quite suitable for carrying in a pocket, which not all flash drives designed to work with USB 3.0 can boast of: a regular, medium-sized rectangular flash drive made of black plastic. Silver parts are the same plastic, but with a metallized coating. Heating during operation is low and does not cause concerns about the survivability of the device during active use. The protective cap is placed on the rear end of the flash drive in a very original way: to do this, it must be rotated 180 degrees.



Volume: 32 GB
Interface: USB 3.0
Manufacturer's stated sequential read speed: 80/30 MB/s (USB 3.0/USB 2.0)
Manufacturer's stated sequential write speed: 60/30 MB/s (USB 3.0/USB 2.0)
Dimensions: 22.2 x 16.1 x 73.7 mm
Weight: 25 g




A massive drive in a very thick case with aluminum inserts and a blue activity LED. In terms of dimensions, only the Corsair Survivor GTR can be compared with it in our four, but, unlike the latter, the Kingston drive cannot boast of extreme security parameters.

During the tests, very strong heating of the drive was noted during operation: after use, the case heats up so much that it is uncomfortable to hold it in your hands - the temperature is clearly approaching 50 °C, which cannot but raise concerns about the life of the device.



What sets this drive apart is the presence of a special cable for improved power supply of the device when connected to USB 2.0 connectors, which by standard provide less current than USB 3.0 (500 mA versus 900 mA). The drive is connected to one connector, and the other two are connected to the USB connectors of the computer, and one of the wires connected to the USB connectors is noticeably thinner than the other and serves only for power supply. True, we were unable to find any benefit from this cable: the power from one USB 2.0 port on our system was enough for normal operation of the drive; there was also no difference in performance or heating of the case when using this cable compared to a direct connection to one port.

Testing methodology

The following configuration was used as a test bench:

Intel "Core i3-2100" processor (3.10 GHz, 2x256 KB + 3 MB);
Mat. board Socket1155 GIGABYTE GA-Z68X-UD3P-B3 (Intel Z68);
Hard drive 3TB Western Digital Caviar Green WD30EZRS 5900 rpm (SATA);
One memory module 1 GB DDR3 SDRAM SEC M378B2873GB0-CH9 (PC10600, 1333MHz, CL9);
Video card HIS HD 3870 IceQ3 Turbo H387Q512NP (Radeon HD 3870);
Power supply Seasonic M12D SS-850EM (850 W);
Operating system Microsoft Windows 7 Ultimate 64-bit SP1.

Testing was carried out with installed drivers from component manufacturers, current as of July 2011. The drives were marked for the NTFS file system with the default cluster size.

All drives were connected to the USB 2.0 controller ports of the Intel Z68 chipset and an additional EtronTech EJ168A USB 3.0 controller integrated into the motherboard.

The following utilities were used to test performance:

FC-Test 1.0 b13
CrystalDiskMark 3.0.1

For FC-Test, we used templates that correspond to three different typical uses of flash drives:

Write and read large files (one file of 900 MB), which is typical for large video files, distributions of large software packages, etc. On the graphs this test is designated as “Large File”;
Write and read files of moderate size (a set of files 2-12 MB in size and a total volume of about 1 GB), which can be compared to copying photos or music in mp3 format. On the graphs this test is designated as “mp3”;
Write and read files of an already installed software package (the template was removed from the folder with Microsoft Office 2007 installed). Although this method of application is not very typical for flash drives, it is the most difficult for them due to the presence of a large number of small files. On the graphs, this test is designated as “Programs”.

CrystalDiskMark was used primarily to provide readers with the ability to compare their results with ours should they wish to do so. In this program, we ran all tests five times with a test data volume of 1000 MB.

Test results

Let's start with the results obtained in CrystalDisk Mark. For each drive, the first screenshot with measurement data refers to a connection via the USB 2.0 interface, the second - to a connection via the USB 3.0 interface.

ADATA C905


As you can easily see, when connected to a USB 3.0 controller, the read speed of an old and rather leisurely USB 2.0 flash drive increases slightly (on average by about 10%), while the write speed remains approximately at the same level (somewhere a little higher, somewhere a little lower). However, even this result was unexpected: we believed that the USB 2.0 interface was already so debugged that there should not be any difference between the controllers.

Corsair Survivor GTR


For a fast (by USB 2.0 standards) Corsair flash drive, the performance increase from switching to a USB 3.0 controller is visible to the naked eye: about a 20% increase in the speed of sequential reading and reading of 512 KB fragments. Small files are read almost twice as fast! But, as in the case of the ADATA drive, the data writing results differ slightly: any noticeable increase is observed only with sequential writing, which is about 10% faster than when working with an Intel USB 2.0 controller.

Kingmax ED-01


Since this model was originally designed to work with the USB 3.0 interface, the sharp increase in reading speed when switching to its native mode is not surprising. But the drive’s problems with writing data are obvious: the native mode is faster than the “heritage” mode only when writing sequentially, and for 512 KB data blocks in USB 3.0 mode there is an outright failure even in comparison with the completely unremarkable results of this test when working with a USB 2.0 controller.

Kingston DataTraveler Ultimate 3.0


The second USB 3.0 drive in our testing turned out to be slower in read speed when working with a USB 2.0 controller than its counterpart discussed above. But when connected to a USB 3.0 port, it outperformed its competitor, and in terms of recording speed, especially small files, it left far behind all rivals in testing.

Now let's move on to the FC-test results. For each of the tests, we compiled two tables (read and write) with the results of all drives controlled by both a USB 2.0 and USB 3.0 controller.



As you can easily see, reading a single 900 MB file when connecting drives to a USB 2.0 connector demonstrates almost complete parity of devices - only the obvious outsider, the ADATA flash drive, is somewhat behind the rest, but even its result cannot be called a crushing defeat.

Connecting to an EtronTech controller brings an increase in speed for all drives, but in very different proportions. The increase in performance of the ADATA drive is purely symbolic, the USB 2.0 model from Corsair adds a little more (but also not too much), and both drives with the USB 3.0 interface, once in their native element, approximately double their results.



When writing a similar file, even using a USB 2.0 controller, the results are already far from the tight group observed during reading. The Kingston drive is somewhat behind the top three, while the budget ADATA is already many times behind its faster rivals.

When switching to a USB 3.0 controller, the picture changes again: the Kingston drive becomes the undisputed leader. Second place is expectedly taken by the second drive with a new interface, but its lag behind the leader is almost one and a half times. It is followed (and also with an almost one and a half times lag) by the fast USB 2.0 flash drive Corsair, and ADATA is hopelessly behind all its rivals.



On medium-sized mp3 template files, the situation with reading data using a USB 2.0 controller is almost the same as observed in the first test - except that the spread between places has slightly increased. Again, the Kingston drive is slightly behind Corsair and Kingmax, and ADATA is again behind everyone else (but not by a critical margin).

With the transition to a USB 3.0 controller, the similarity with the previous test becomes almost absolute.



But in the recording the picture changes quite significantly.

First of all, the complete and absolute failure of the Kingmax drive in interaction with both versions of the USB interface is striking. When working with a USB 2.0 controller, it managed to lag behind even a cheap ADATA flash drive, and the transition to the “native” third version of USB only allowed it to catch up. The gap between this pair and Corsair and Kingston drives turned out to be simply hopeless.

Secondly, we can note the excellent results of the Corsair USB 2.0 drive and the simply excellent performance of the Kingston model in USB 3.0 mode.



In the test for reading a folder template with Microsoft Office 2007 installed, where there are a lot of small files and a number of larger ones (a total of 3384 files for 450 MB of volume), in USB 2.0 mode the ADATA flash drive scored the second “prestige goal” in the test. This time she managed to bypass the Kingston drive, which does not read very quickly in USB 2.0 mode. Corsair and Kingmax drives are ahead with almost equal performance in this mode.

When working with a USB 3.0 controller, the Kingmax drive remains the leader in reading, but the Kingston comes in second place in speed, overtaking the Corsair model, which is unable to take advantage of the newer interface, although it noticeably increases speed when working with the EtronTech controller.



Writing large numbers of small files has traditionally been the most challenging test for flash memory. In this test, the pairs of winners and outsiders were clearly identified. The ADATA and Kingmax models are trailing behind, not even reaching 1 MB/s average write speed. The leaders (as expected based on previous recording results) were Kingston and Corsair models, and even in USB 2.0 mode, the Kingston drive is almost twice as fast as its rival, and with the transition to USB 3.0 its advantage increases to almost five times.

Summarizing

As we have found out, the compatibility between USB 2.0 and USB 3.0 controllers and devices is truly excellent. In most cases, USB 3.0 drives, when connected to USB 2.0, show better performance results than devices specifically designed for use with USB 2.0 (unfortunate exceptions include the Kingmax drive, which failed to write medium and small files - but its results were also achieved with a USB 3.0 controller not better). Moreover: even drives designed for the USB 2.0 interface often improve performance when connected to a USB 3.0 port (which was especially noticeable in the example of the “fast” Corsair drive). An excellent result for the EtronTech controller, even without taking into account the fact that working with USB 2.0 is not a priority for it, and Intel USB controllers have always had a reputation for being quite fast.

As for the operation of USB 3.0 drives with a USB 2.0 controller, the reading parameters of both reviewed models with a fresh interface were generally at the level of one of the fastest USB 2.0 drives - the Corsair Survivor GTR. However, it is worth noting that Kingston DataTraveler Ultimate 3.0 was somewhat inferior to its rivals, most noticeably lagging behind in reading small files.

According to the recording, the situation turned out to be different: the Kingston drive, which did not shine in reading via USB 2.0, turned out to be out of competition when writing small files, doubling here the Corsair Survivor GTR, which confidently took second place. The Kingmax ED-01 drive, which showed excellent results when reading from the “legacy” interface, performed decently only when writing large files, in other parameters it was hopelessly inferior to Kingston and Corsair drives (and even a modest ADATA flash drive overtook it on medium-sized mp3 template files) .

If we consider the operation of Kingmax and Kingston drives under “natural conditions”, i.e. when connected to a USB 3.0 controller, Kingston is ahead in terms of reading speed for large and medium-sized files, but Kingmax reads small files somewhat faster. By recording, Kingston is simply beyond the reach of its today's rival: even when working with a single large file, its advantage is close to 50%, and on small and medium-sized files the speed gap is measured dozens of times!

Overall, Kingston DataTraveler Ultimate 3.0 shows excellent results when recording files of any size, which can confidently be called its main advantage. The disadvantages (in addition to the indecent heating during operation and immodest dimensions noted at the first acquaintance) include only the relatively low speed of reading files (especially small ones) when working via USB 2.0, as well as potential problems with the need for additional power when connecting to USB 2.0 ports . In addition to a rather large flash drive, carrying around a splitter cable is clearly a below-average pleasure.

However, the second generation of drives in this line is already available - DataTraveler Ultimate 3.0 G2 - for which representatives do not require additional power when connected to USB 2.0, and the declared speed characteristics are even more impressive: up to 100 MB/s for reading and up to 70 MB/s for record.

The Kingmax ED-01 drive has another set of advantages: it has no failures in any reading modes (including quite reliable work with the USB 2.0 interface), as well as much more convenient dimensions for carrying. The price, presumably, should also be more affordable (at the time of testing, this model had not yet appeared on sale). However, the extremely low performance when recording medium and small files casts doubt on the advisability of purchasing this model.

To sum up, all that remains is to play the role of Captain Obvious: although the USB 3.0 interface itself is, without a doubt, significantly superior to USB 2.0, the real performance of flash drives designed for it is determined not only by the interface, but also by the speed of the flash memory used, as well as “ the reasonableness of the controller - a flash drive on which, when writing small files, the speed drops below megabytes per second, changing the interface will not help in any way. Thus, the use of USB 3.0 clearly allows you to achieve high read and write speeds for large files, but when working with small files, everything may not be so clear. Unfortunately, the fierce price competition of flash drive manufacturers may lead to the fact that after some time in the USB 3.0 flash drive market the situation with USB 2.0 flash drives will be repeated, where for one fast model there are two dozen slow ones that are not able to fully load even an interface that was more than ten years old.

Other materials on this topic


USB 3.0: does it make sense for a card reader?
USB 3.0 - theory and practice

  • Mini-B Connector ECN: Notice issued October 2000.
  • Errata, since December 2000: Notice issued December 2000.
  • Pull-up/Pull-down Resistors ECN
  • Errata, since May 2002: Notice issued May 2002.
  • Interface Associations ECN: Notice issued May 2003.
    • New standards have been added to allow multiple interfaces to be associated with a single device function.
  • Rounded Chamfer ECN: Notice issued October 2003.
  • Unicode ECN: Notice issued February 2005.
    • This ECN specifies that strings are encoded using UTF-16LE.
  • Inter-Chip USB Supplement: Notice issued March 2006.
  • On-The-Go Supplement 1.3: Notice issued December 2006.
    • USB On-The-Go makes it possible for two USB devices to communicate with each other without a separate USB host. In practice, one of the devices acts as a host for the other.

USB OTG

USB 3.0

USB 3.0 is in the final stages of development. The following companies are developing USB 3.0: Microsoft, Texas Instruments, NXP Semiconductors. In the USB 3.0 specification, connectors and cables of the updated standard will be physically and functionally compatible with USB 2.0. The USB 2.0 cable contains four lines - a pair for receiving/transmitting data, one for power, and one more for grounding. In addition to these, USB 3.0 adds five new lines (resulting in a much thicker cable), but the new pins are located parallel to the old ones on a different pin row. Now you can easily determine whether a cable belongs to one or another version of the standard, simply by looking at its connector. The USB 3.0 specification increases the maximum transfer speed to 4.8 Gbps - which is an order of magnitude higher than the 480 Mbps that USB 2.0 can provide. USB 3.0 boasts not only higher data transfer speeds, but also increased current from 500 mA to 900 mA. From now on, the user will not only be able to power a much larger number of devices from one hub, but the hardware itself, which was previously supplied with separate power supplies, will get rid of them.


Here GND is the “case” circuit for powering peripheral devices, VBus is +5 V, also for power supply circuits. Data is transmitted differentially through the D+ and D− wires (states 0 and 1 (in the terminology of the official documentation diff0 and diff1, respectively) are determined by the potential difference between the lines of more than 0.2 V and provided that on one of the lines (D− in the case of diff0 and D+ at diff1) potential relative to GND is higher than 2.8 V. The differential transmission method is the main one, but not the only one (for example, during initialization, the device informs the host about the mode supported by the device (Full-Speed ​​or Low-Speed) by pulling up one of the lines data to V_BUS through a 1.5 kOhm resistor (D− for Low-Speed ​​mode and D+ for Full-Speed ​​mode, devices operating in Hi-Speed ​​mode behave at this stage as devices in Full-Speed ​​mode). Also sometimes around The wires have a fiber winding to protect them from physical damage.

USB 3.0 type B connector

USB 3.0 connector type A

USB 3.0 cables and connectors

Disadvantages of USB

Although USB 2.0 has a peak throughput of 480 Mbps (60 MB/s), in practice it is not possible to achieve anything close to the peak throughput. This is explained by the rather large delays on the USB bus between the request for data transfer and the actual start of the transfer. For example, the FireWire bus, although it has a lower peak throughput of 400 Mbps, which is 80 Mbps less than USB 2.0, actually allows for greater throughput for data exchange with hard drives and other storage devices.

USB and FireWire/1394

USB storage protocol, which is a method for transmitting commands

In addition, USB storage was not supported in older operating systems (the original Windows 98), and required driver installation. SBP-2 was also supported in them. Also, in older operating systems (Windows 2000), the USB storage protocol was implemented in a truncated form, which did not allow the use of the CD/DVD burning function on a USB drive connected; SBP-2 never had such restrictions.

The USB bus is strictly oriented, so connecting 2 computers or 2 peripheral devices requires additional equipment. Some manufacturers support connecting a printer and a scanner, or a camera and a printer, but these implementations are highly manufacturer-specific and are not standardized. The 1394/FireWire bus is not subject to this drawback (you can connect 2 video cameras).

However, due to Apple's licensing policies, as well as the much higher complexity of the hardware, 1394 is less common, older computer motherboards do not have 1394 controllers. As for peripherals, 1394 support is usually not found in anything other than camcorders and enclosures for external hard drives and CD/DVD drives.

see also

  • FireWire
  • TransferJet

Sources

Links

  • USB News (German)
  • List of USB ID's (Vendors, devices and interfaces) (English)

Literature

  • Scott Mueller. Upgrading and Repairing PCs (Chapter 15 - Serial, parallel and other input/output interfaces - USB) = Upgrading and Repairing PCs. - 17th edition - M.: “Williams”, 2007. - S. 1016-1026 . - ISBN 0-7897-3404-4

I am glad to welcome readers to my blog!
In today’s article we’ll talk about USB, or more precisely about the difference between USB 2.0 and USB 3.0 and what opportunities they provide for use on your computer

The ancient parallel LPT ports and serial COM ports have almost sunk into oblivion. Finally, computer users have begun to get rid of thick communication cables, keyboards and mice with COM tips and PS/2 connectors. They were replaced by the universal USB interface, in the English interpretation - Universal Serial Bus. And a universal port is universal so that, without hesitation, you can connect various external devices to it: large and small, low-speed and high-speed, powerful and low-power.

History of the creation of Universal Serial Bus

Developers of desktop computers and laptops have long been thinking about replacing various communication connectors with one universal one, capable of solving all possible problems. The first examples of the Universal Serial Bus interface began to appear in 1994-1996 and were designated USB 1.0. The novelty spurred the market for external devices, and by 2000, most printers, scanners and other devices began to be equipped with a newfangled interface. A big plus in the development of USB was the appearance in 1999 of the first 8 MB flash drive, which appealed to all users.

USB 2.0

In 2000, the world saw a new version - USB 2.0. She became forty times more productive than her predecessor. If USB 1.0, according to the specification, had a maximum data transfer speed of 12 Mb/s (megabits per second), now the speed has increased to 480 Mb/s. The successes did not arise out of nowhere - it is known that about 400 interested companies took part in the development of the innovation, including such well-known brands as Intel, IBM, Hewlett-Packard, Compaq, Microsoft, NEC, Philips and many others.

USB 3.0

Enraged by the unprecedented results, the developers did not stop there and in 2008 proposed USB 3.0. The new specification made it possible to increase the data exchange speed by another 10 times and reached a value of 4800 Mb/s, which is equivalent to 4.8 Gb/s. At this speed, information from a 1-terabyte medium can theoretically be downloaded in less than 30 minutes (at a maximum possible speed of 600 MB/s), if there are no other restrictions.

It should be noted that the near future lies with this type, so when buying a new motherboard, make sure that it supports this connection standard.

Design differences between USB 2.0 and USB 3.0 connectors

How does USB 2.0 differ from USB 3.0 in design terms? In fact, they are partially compatible, but the latter contains an additional 4 more contacts for connecting two signal twisted pairs. The previous version has only 4 contacts: two signal, power and ground, the housing is used as a screen. Partial compatibility involves the fact that you can easily plug a USB 2.0 plug into the USB 3.0 variant’s socket, and everything will work, only at a reduced speed, according to the 2.0 specification. The same thing will happen when you connect a USB 3.0 plug to a USB 2.0 socket. Those connector options that are not included in the connection, naturally, will not work.

You can visually distinguish USB 3.0 ports from USB 2.0 ports by color - version 3 is blue, while version 2 is black. The forks themselves are also different - blue and black.

In addition, there are several design options for USB connectors. Here are the main types of USB 2.0 connectors: type A regular (4x12 mm), Mini (3x7 mm) and Micro (2x7 mm); type B regular (7x8 mm), Mini (3x7 mm) and Micro (2x7 mm). The overall dimensions of the connecting part of the connector given in parentheses are rounded.

The designs of USB 3.0 connectors currently in use are as follows. For type A, only the regular version is used, for type B there is a regular, Mini and Micro version. For both specifications 2.0 and 3.0, universal connector options have also been developed: Mini-AB and Micro-AB. Type A and type B mating parts can be connected to them without problems. The USB 3.0 version additionally has a Powered-B type with reinforced power contacts. Manufacturers have also agreed that all USB 3.0 connectors will be blue to visually identify the port specification and its potential.

In practice, you can also use various adapters from one type to another. This is convenient when, for example, you have a mini-usb cord, and you want to connect a phone with a micro-usb socket to your computer. Or if you need to make a usb-microUSB option out of a usb-usb cable.

How to use computer USB?

Due to the fact that a large number of external devices are now able to connect via a USB port, the mechanical loads on these connectors have increased many times over. Frequent connection of flash drives, players, and all kinds of chargers leads to mechanical abrasion of parts and weakening of electrical contacts. Moreover, the consumer may accidentally hit the cable connector or flash drive, which will damage the port and require repair. If the connector is installed on a separate printed circuit board connected to the main board via a cable, then this is not so bad. If the USB connector is soldered directly into the motherboard, then repairs will be expensive.

To avoid trouble, the consumer should be careful and evenly use all USB connectors available on the computer. In addition to the built-in connectors, you can purchase an additional PCI expansion card with USB ports. It is installed in the corresponding PCI slot on the motherboard and provides additional connectors for connecting external devices to the outside of the case.

Also, as an option, you can purchase a USB port splitter (external hub). It will increase the number of connectors and secure the computer itself.

However, you need to take into account that through such a splitter it will not be possible to connect energy-intensive devices, for example, an external hard drive without additional power. In addition, the consumer sometimes allows powerful loads to be connected to the main port, such as an external hard drive or several loads that together exceed the energy capabilities of the power bus. This can lead to burnout of the protective elements of the circuit and failure of the interface to operate. To prevent this from happening, you need to remember that USB 2.0 can supply a maximum of 500 mA of current to the power line, and USB 3.0 - 900 mA. For more powerful loads, it is recommended to use external power supplies.

Another danger lies in incorrectly turning on/off, for example, a flash drive in “hot” mode, as well as the action of static electricity. Although the developers guarantee the safety of this mode, it is advisable to carry out all communications when the computer and external device are turned off. As for static electricity, this is the number one enemy of dry heated rooms. A dangerous charge accumulates on a person’s body and clothing, and in order to remove it, it is necessary to touch the grounding bus, water pipe or water heating radiator.

Now the user has the necessary knowledge about the correct operation of the USB 2.0 and USB 3.0 ports of the computer, and the recommendations given will allow you to solve the tasks without problems and successfully.

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USB 3.0 or USB Super Speed- new generation of USB interface (Universal Serial Bus).

Its key difference from the previous version of USB 2.0 (or High Speed) is that the maximum theoretical data transfer rate has increased from 480Mbit/s to 5Gbit/s.
A less obvious, but equally important point is that with version 3.0 USB will not only overclock, but also become isochronous and full-duplex, i.e. will gain the ability to independently transmit data in both directions at maximum speed. Earlier versions of USB were half-duplex, and the stated maximum speed was achieved only when transferring data in one direction. This improvement is critical for future high-speed USB 3.0 and other storage devices, as the interface will not limit the device's simultaneous read and write capabilities.
In practice, a maximum stable data transfer rate of about 380 MB/sec is achieved between the controller and the device, which, for example, is faster than the actual speed of SATA-II (about 250 MB/sec), and is more than an order of magnitude higher than the same parameter for USB2.0 and IEEE1394.

In order to achieve these characteristics, USB 3.0 SuperSpeed ​​was the first to seriously change the design of the connectors, while maintaining maximum compatibility with previous versions of the standard where possible.
In addition to the power, ground and differential pair lines for data transmission available in previous versions of the standard, two more differential pairs for SuperSpeed ​​mode and a separate shield were added, which is why the design and diameter itself began to resemble shielded twisted pair (STP) category 6. and the SuperSpeed ​​part of USB 3.0, in terms of performance and the information transfer methods used, is very similar to PCI-E 2.0 1x in external design, unfortunately, being completely incompatible with it.

A new type of connector has been added - USB Powered B. In addition to the contacts already available in USB 3.0, two fundamentally new ones have been added - DPWR and DGND, which provide the ability to power the controller with a device connected to it (and not vice versa, as was the case in all other versions of the interface ).

The power supply of devices has been enhanced - now the USB3.0 controller can supply up to 900 mA instead of 500 mA in the previous version of the interface. The minimum "portion" of current has been increased to 150mA, i.e. one controller can “feed” 6 devices of 150 mA each, or one can eat all 900. Naturally, intermediate options are possible. The minimum operating voltage of the connected device is reduced to 4 Volts.

The improvements affected not only the physical level - unlike USB 2.0 HighSpeed, the USB 3.0 SuperSpeed ​​controller organizes an individual virtual channel to each device, rather than broadcasting all transmitted data to all devices connected to the controller (and they themselves figure out which of the received packets data was really intended for them), this allows, with some reservations, to call USB 3.0 a hub - a switch, which it actually is.

Perhaps the only noticeable drawback of USB 3.0 so far is the reduction in the maximum length of SuperSpeed ​​to 3 meters, but perhaps this information will be clarified in the future, and based on the results of mass implementation, this figure may change fundamentally, both up and down.

The mechanical life of conventional full-size USB 3.0 connectors is designed for one and a half thousand “connection-disconnection” cycles, high-strength connectors - for five thousand such cycles, and the USB 3.0 Micro connector is the most “survivable” - it should withstand up to ten thousand connections and disconnections.

2.Types of connectors and compatibility.

USB 3.0 MicroB connectorUSB 3.0 connectors "A" and "B" USB 3.0 regular "A" and MicroB

SuperSpeed ​​connectors, in addition to the four contacts kept in the usual places for compatibility with previous versions of the standard, received five more specific contacts, located deeper inside the connectors and necessary for operation in the new speed mode. However, full backward compatibility has not been achieved, so we briefly list the outcomes of possible combinations:

  • A USB 2.0 device with a USB type A connector, for example a flash drive, can be connected to a USB 3.0 controller, and it will work there.
  • A USB 2.0 device with a USB type B connector, for example, can be connected to a USB 3.0 controller using a standard USB 2.0 AB cable, and it will work there; the connectors on the cable simply will not reach the contacts responsible for USB 3.0.
  • A USB 3.0 device with a USB Type A connector can be connected to a USB 2.0 controller, and it should work there in USB 2.0 modes.
  • A USB 3.0 device will not work with a USB 1.1 controller.
  • USB 3.0 Type B cable cannot be connected to a USB 2.0 connector, the old type connectors have a different shape. At the same time, the USB 2.0 type B cable fits into the USB 3.0 type B connector.


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