Why is USB3.0 better than USB2? Why do we recommend buying USB3? After reading the following three points, you will understand the difference between USB 3.0 and 2.0.
▮ data transmission
USB3.0 introduces complete duplex data transmission. Of the five lines, two are for sending data, the other two are for receiving data, and one is connected to the ground. In other words, USB 3.0 can read and write synchronously at full speed. Previous USB versions did not support full-duplex data transfer.
▮ Data transmission rate
The USB flash drive is connected to the system through a USB interface, and the speed of the interface limits the data transfer rate of the portable hard drive. Currently, the maximum transfer bandwidth of USB 2.0 is 480Mbps (60MB/s), while the maximum transfer bandwidth of USB 3.0 is up to 5.0Gbps (500MB/s). The USB 3.0 standard requires that the current capacity of the USB3.0 interface is 1A, while that of the USB 2.0 interface is 0.5A. However, the transmission speed in the application slows down for objective reasons (e.g. whether the production quality of the main control chip and the circuit board used in the storage device is good or not).
Look at the USB port (itself) and the USB port on the computer. The color of the plastic sheet in the middle is USB3.0 – blue. USB – black. Of course, some devices’ color distinction is not standard, for example, some main control chips support non-native USB3.0 can not be blue, some USB 2.0 devices such as MP3, the data cable can be black or white plastic film. Also, USB 3.0 lines are “thicker” because USB 3.0 has four internal wires more than two. 0 wires. However, this connector is USB 3.0 by default. Includes additional connected devices.
▮ Datasheet comparison of USB2.0 & USB3.0
|Transfer Speed||Low-Speed (1.5Mbit/s)|
|Name of large |
|SuperSpeed USB (SS)||Hi-Speed USB (HS)|
|Max Range||3m (Under normal conditions)||5m|
|Data Interface||Dual simplex|
The four-wire differential signal is separated from the USB2.0 signal and real at the same time
Bidirectional data flow
|Half duplex, two wire differential signal|
|Bus transaction protocol||Host-oriented, bound step transfer stream, USB packet transfer has a determined route||Host directed, polling transfer stream, USB packet broadcast to|
All the equipment
|Bus Type||USB 3.0 uses a dual simplex four-wire differential signal line for point to point|
Full duplex communication
|USB 2.0 is based on a half-duplex and two-wire bus for broadcast mode communication|
|Cable||USB 3.0 Shielded Differential Pair (SDP) The sheltered|
Differential signal PAIR) line
|USB 2.0 uses a slim, unshielded pair|
Shielded Twisted Pair (Unshielded Twisted Pair)
|Number of Cable signals||A total of 6|
Four are used for ultra-high speed data transmission (SSTX+, SSTX-, SSRX+, SSRX-).
The other two are for general transmission (D+, D-)
|2 (D+, D-)|
|Port State||Port hardware detection connection parts. And set the port to the operation state for super high|
Fast data communication
|Port hardware detects connection events. Use of system software|
Port command to switch the port zhao status
|Data transmission type||USB type with ultra-high speed constraints||Only four basic transport types are supported|
|Power Management||Multilevel power management: standby, sleep, pause, and enable||Only device-level power management is supported|
|Bus power supply capability||Low power equipment: 5V, maximum 150mA|
High power consumption device: 5V, maximum 900mA
|Low power equipment: 5V, maximum 100mA|
High power consumption device: 5V. Maximum 500mA
▮ Words in the end
In short, USB 3.0 has the advantages of fast transmission speed, simple operation, hot swap support, flexible connection, and independent power supply. But for device compatibility, USB 2.0 is currently better.