USB Implementers Forum announces USB 4, which offers a maximum speed of 40 Gbps, double that of USB 3.2, and support for Thunderbolt 3
Jon Porter / The Verge :
Context & Ripple Effects
Two years after the USB 3.2 specification doubled speeds to 20 Gbps over existing Type-C cables, the USB Implementers Forum is doubling again: USB 4 tops out at 40 Gbps and, more significantly, builds in Thunderbolt 3 compatibility — folding Intel's proprietary high-speed protocol into the open USB standard for the first time.
The move sets up the rest of the arc in this corpus: Intel's follow-on Thunderbolt 4 standard requires USB4 compatibility rather than competing with it, and by 2022 the two tracks merge outright when the Promoter Group's USB4 version 2 pushes to 80 Gbps on the same connector.
First-order effects
- Device and laptop makers get one spec instead of two: ports built to USB 4 must interoperate with Thunderbolt 3 gear, ending the split between 'USB-C fast' and 'Thunderbolt fast' machines at the 40 Gbps tier.
- Intel loses Thunderbolt 3's exclusivity as a differentiator — its licensed protocol is now a mandatory feature of a standard any USB-IF member can implement.
Second-order effects
- Cable and dock vendors face a new certification cycle, since 40 Gbps performance depends on cable quality — the same confusion problem that pushed the USB-IF toward certified logos marking power and speed tiers.
- Intel responds by repositioning Thunderbolt upmarket: Thunderbolt 4 layers extra requirements like multi-monitor support on top of USB4 compatibility, keeping a premium tier above the now-common baseline.
Third-order effects
- If the pattern holds, USB and Thunderbolt converge into a single escalating roadmap — one connector family where each generation doubles bandwidth, with Intel contributing protocol work rather than guarding a walled garden.
- The structural cost is naming clarity: as specs layer (USB 3.2, USB 4, USB4 v2, Thunderbolt 3/4), buyers increasingly rely on certification marks rather than version numbers to know what a port actually does.
The trend: USB and Intel's Thunderbolt are consolidating into one jointly developed high-speed standard whose generations double bandwidth on a shared USB-C connector.