USB interface is used wildly in many fields, such as consumer, communication, automotive medical etc., but do you know the difference between USB 2.0 and USB 3.0? USB 2.0 is old generation USB interface, USB 3.0 is new generation USB interface with more contacts and higher data transmission speed. Please refer to below for more detail of their difference.
1, Transmission speed
USB 2.0: The theoretical maximum transfer rate is 480 Mbps (approximately 60 MB/s), but in practical use it is usually 30-40 MB/s.
USB 3.0: The theoretical maximum transfer rate is 5 Gbps (approximately 625 MB/s), but the actual speed can reach 100-200 MB/s, and even higher in some scenarios.
2, Interface appearance
Color identification: USB 2.0 interfaces are often black or white, while USB 3.0 interfaces are mostly blue.
Pin quantity: USB 2.0 socket has 4 pins, USB 3.0 socket has 9 pins, and a metal shielding layer is added internally to improve stability.
Special symbol: The USB 3.0 interface is usually marked with the "SS" (SuperSpeed) symbol next to it.
3, Power supply capability
USB 2.0: The maximum power supply current is 500 mA (with a power of approximately 2.5 W).
USB 3.0: Maximum power supply current increased to 900 mA (power of approximately 4.5 W), supporting higher power consumption peripherals.
4, Data transmission mechanism
USB 2.0: adopts half duplex mode, and can only transmit data unidirectionally at the same time.
USB 3.0: adopts full duplex mode, supports bidirectional simultaneous data transmission, and has higher efficiency.
5, Compatibility
Backward compatibility: USB 3.0 devices are compatible with USB 2.0 interfaces, but the transfer speed will be reduced to the level of USB 2.0; USB 2.0 devices can also be plugged into USB 3.0 interfaces for use.
6, Application scenarios
USB 2.0: Suitable for low-speed devices (such as mice, keyboards) or small file transfers.
USB 3.0: More suitable for transferring large files (such as high-definition videos, large software) and high-power devices (such as external hard drives).
