Summary
Highlights
Evolution of USB Standards00:00:01
USB (Universal Serial Bus) has become the standard connection for many computer peripherals. USB 1.1 offered low speed (1.5 Mbps) and full speed (12 Mbps) over cables up to 3-5 meters. USB 2.0 significantly improved throughput to 480 Mbps over 5-meter cables. USB 3.0, known as SuperSpeed, provides 5 Gbps over 3-meter cables. Subsequent updates, USB 3.1 and USB 3.2, further increased speeds to 10 Gbps and 20 Gbps, respectively.
USB Connector Types00:01:34
Early USB 1.1 and 2.0 utilized Standard-A, Standard-B, Mini-B, and Micro-B plugs. USB 3.0 introduced updated versions of the Standard-A, Standard-B (taller), and a significantly different Micro-B connector. The proliferation of various connector types led to the development of USB-C, a standardized, reversible connector designed to replace previous types and capable of carrying different signal types.
Serial Cables00:03:33
Before USB, serial cables were common, with popular types being the DB-9 and DB-25. These connectors are named for their size and number of pins (though DB-9 is technically a DE-9). They use the RS-232 standard for serial communication, established in 1969. While largely replaced by USB for modern peripherals, DB-9 connectors are still used for legacy equipment like older switches and routers, often requiring USB-to-serial adapters for modern computers.
Thunderbolt Technology00:06:40
Thunderbolt is a high-speed serial connection that carries both data and power. Early versions, Thunderbolt 1 and 2, used the Mini DisplayPort connector, offering 20 Gbps total throughput across two aggregated 10 Gbps channels. Modern Thunderbolt 3 adopted the USB-C connector, providing 40 Gbps aggregated throughput. Thunderbolt 3 supports copper cables up to 3 meters and optical cables up to 60 meters, and allows for daisy-chaining multiple devices. Thunderbolt 4 maintains 40 Gbps but enhances video output to support dual-4K displays and increases bandwidth to the PCIe bus.