USB Cheat Sheet: Complete Guide to Standards and Performance
Original: USB Cheat Sheet (2022)
Why This Matters
Clarifies complex USB standards evolution for developers and hardware engineers
Developer Fabien Sanglard published a comprehensive USB reference guide in May 2022, detailing speed specifications from USB 1.1 (12 Mbps) to USB4 (40 Gbps), connector types, power delivery capabilities up to 240W, and real-world performance metrics for all major USB standards.
The cheat sheet addresses confusion in USB terminology by providing clear comparisons of marketing names versus technical specifications. It covers USB evolution from 1.1's 1.5 MiB/s to USB4's 5000 MiB/s theoretical speeds, explaining how encoding overhead affects real-world performance. The guide details connector wiring from 4-wire USB-A/B (half-duplex) to 12-wire USB-C (four lanes), and power delivery progression from USB 2.0's 2.5W to USB-C PD 3.1's 240W. Key insights include lane striping/bonding mechanics, cable length limitations, and the gap between advertised speeds and actual sequential read rates. References include official specifications and independent performance testing.