USB is now the most common interface for connecting peripheral devices to the computer. Via USB you can connect printers, scanners, mouse, keyboard, external drives. In place of the usual USB 2.0 interface coming soon new and improved the USB 3.0 interface.
The abbreviation USB stands for “universal serial bus”. This interface is used to connect low-speed and medium-speed peripherals. In 1996 was released the specification USB 1.0. She supported a data transfer rate up to 12 Mbit/s high-speed interface mode USB 2.0. introduced in 2000, supports data transfer up to 480 Mbps. Now this interface is most common and is used in most peripheral devices. But to replace him is coming soon the new high speed interface USB 3.0.
The final specification for USB 3.0 was introduced in 2008, but he still has not entered into mass use. What are the main features of the USB 3.0 interface. What can we expect from him?
The necessity of introduction of USB 3.0 interface due to the fact that many modern devices require higher data transfer speed. Besides, they have enough power, which can provide USB 2.0. USB 3.0 interface supports more than high speed data transfer up to 4.8 Gbit/s. This is achieved, among other things, by additional communication lines. A standard USB 2.0 cable contains four lines - a twisted pair for data transmission and reception, as well as two power lines (plus and zero). The USB 3.0 cable is thicker, because two more twisted pairs (ie four new communication lines) were added to it. However, the USB 3.0 cable will be shorter (the maximum length is 3 meters compared to 5 meters for USB 2.0). From the use of optical fiber in USB 3.0 decided to abandon, because it is very expensive for mass use.
Controllers and connectors USB 3.0 USB 2.0 compatible, both physically and functionally. USB 3.0 plug includes contacts of the USB 2.0 standard, but in the back of the connector there is another contact number with five contacts. Connector cable will allow at a glance to determine the version of the USB standard. However, such an arrangement of contacts means that the USB 3.0 plug to be inserted into the appropriate port “to stop.” If you insert the plug into the port is not full, additional contact number will not be used, so the data transfer rate will match the USB 2.0 interface.
A little more aboutcompatibility devices with USB 2.0 and USB 3.0. Devices with a USB 2.0 A connector (for example, a USB flash drive) can be connected to the USB 3.0 port and vice versa, however, in this case, the transfer and reception speed will correspond to the USB 2.0 interface. A device with a USB 2.0 Type B connector (for example, a printer) is connected to the USB 3.0 port, but vice versa. Also, the USB 3.0 cable will not work if it is connected to the USB 1.1 controller.
Also, USB 3.0 was increased amperage (900 mA compared to 500 mA in USB 2.0). This will eliminate the additional power supplies and USB connectors in many devices. Particularly important is the current strength for portable hard drives. This will also allow faster charging of mobile devices from USB.
The introduction of the USB 3.0 interface will inevitably lead to the emergence of newUSB hubs (hubs) with support for USB 3.0. which allow you to connect multiple devices to a single USB controller. Hubs that support USB 3.0 will be more difficult as they have to simultaneously support USB 2.0. Therefore, it is likely that the first generation of such hubs will be expensive.
However, the USB 3.0 interface more not supported by all operating systems and motherboards. Some manufacturers have already released motherboards with USB 3.0 support on the market, but some companies do not hurry to implement support for USB 3.0 in their chipsets, believing that this standard will not immediately become massive.
A new Linux kernel. according to the developers, already supports USB 3.0. But Windows 7 while this can not boast: the final specification of USB 3.0 was announced shortly before the release of this operating system, so the developers did not have time to implement support for the new interface. However, it is possible that USB 3.0 support will be available by installing OS updates. However, it is not known whether USB 3.0 support and SuperSpeed technologies are implemented for Windows XP and Windows Vista.