What are the main differences between USB 1.1, 2.0, 3.0 and 4.0?

USB 1.1, as the early version of USB technology, has a maximum transmission rate of only 12 Mbps, which seems rather slow by today's standards. It was mainly used to connect low-speed devices like early mice and keyboards. Although the transmission rate was limited, USB 1.1 supported hot plugging and plug-and-play, bringing great convenience to users.

With the development of technology, USB 2.0 emerged, with a maximum transmission rate of 480 Mbps, which is 40 times that of USB 1.1. This improvement significantly enhanced the efficiency of data transmission, allowing users to transfer files, pictures, and other data more quickly. Additionally, USB 2.0 retained the hot plugging and plug-and-play features of USB 1.1 and added support for more devices. However, as high-definition videos, large-capacity storage devices, and other applications became increasingly widespread, the transmission speed of USB 2.0 gradually became insufficient.

To further enhance the transmission rate, USB 3.0 and subsequent versions were successively launched. The theoretical transmission rate of USB 3.0 is up to 5 Gbps, which is more than ten times that of USB 2.0. This speed improvement enables USB 3.0 to easily handle the transmission requirements of high-definition videos, large-game applications, and other large-capacity data. At the same time, USB 3.0 also added support for larger power-hungry devices and improved the power supply capacity of the bus. In terms of interface type, USB 3.0 adopted a new blue tongue design to distinguish it from the black tongue of USB 2.0, making it easier for users to identify.

The latest USB 4.0 has achieved comprehensive improvements in transmission rate, power supply, compatibility, and power transmission. USB 4.0 supports a maximum data transmission speed of up to 40 Gbps, which is twice that of USB 3.2 Gen 2x2. This speed is sufficient to meet the data transmission requirements of large amounts of data and high-speed transmission in the coming period. At the same time, USB 4.0 adopted the USB Type-C interface, a small and reversible plug design, which eliminates the need for users to worry about the direction when inserting. Additionally, USB 4.0 supports multiple data protocols and functions, including USB, Thunderbolt 3, DisplayPort, and PCI Express, allowing it to connect to a wider range of devices. In terms of power transmission, USB 4.0 also has stronger capabilities and can be used for charging and power supply connections to devices.

In summary, USB 1.1, 2.0, 3.0, and 4.0 have significant differences in transmission rate, power supply, compatibility, and interface type. With the continuous advancement of technology and the expansion of application scenarios, USB interfaces are constantly evolving and upgrading to meet users' needs.