USB4 Is Coming: Here Is The Speed

USB 3.2, the most recent widely deployed standard at the time of its introduction, supports maximum transfer speeds of up to 20Gbps under its fastest configuration. USB4 builds on that foundation and raises the ceiling to 40Gbps, with the newer USB4 Version 2 specification extending bandwidth even further to a theoretical 80Gbps. Put another way, 80Gbps is equivalent to moving roughly 10,000MB of data in a single second, or about 10GB per second.

Keep in mind this is all theoretical maximum throughput. Real-world performance will always be lower due to protocol overhead, controller limitations, cable quality, and storage speed. That gap between headline numbers and actual transfer rates has always existed and will continue to do so.

USB4 is built on Intel’s Thunderbolt technology, a high-speed interface Apple strongly promoted starting around 2012. While Thunderbolt delivered excellent performance, licensing costs and strict certification requirements kept accessory prices high and limited widespread adoption. Intel’s long-term goal was always to merge Thunderbolt into USB, bringing higher speeds to the mainstream at more affordable price points.

USB4 maintains backward compatibility with USB 3.2, USB 2.0, and Thunderbolt 3 devices. Because the standard fully embraces the USB-C connector and unifies multiple protocols, manufacturers can design fewer ports while supporting more use cases. As USB4 adoption increases, faster cables, docks, and storage devices are already becoming more common and less expensive.

USB4 devices are also required to support USB Power Delivery, which intelligently manages charging and power negotiation. This allows everything from smartphones to high-performance laptops to draw the correct wattage safely and efficiently from the same port.

Early USB4 products began appearing in the market in 2020, and today the ecosystem is steadily expanding as controllers, cables, and host systems mature. This post was originally prompted by the release of the finalized specification from the governing body, USB-IF, and the momentum behind USB4 has only increased since then.