Science | USB4 vs Thunderbolt

Science | USB4 vs. Thunderbolt 3/4: What's the Real Difference?

The 40Gbps high-speed cable landscape explained

Industry Knowledge | 2026-11-03

USB4, Thunderbolt 3, Thunderbolt 4... do these high-speed interface standards leave you confused? They all do 40Gbps, they all use Type-C connectors - so what's the actual difference? Let's sort it out.

Thunderbolt 3: Intel's High-Speed Standard

Thunderbolt was co-developed by Intel and Apple as a high-speed interface standard. Thunderbolt 3 reached 40Gbps - four times the speed of USB 3.2 Gen2 at 10Gbps. Thunderbolt 3 can do data, video output, external GPU, and high-speed storage - it's extremely capable. But Thunderbolt 3 licensing was expensive, so it was mostly found on premium computers and professional equipment.

USB4: The Merged Standard

USB4 is a standard released by the USB-IF in 2019, and it's built on Thunderbolt 3 technology. Put simply: Intel contributed Thunderbolt 3 to the USB-IF, and the USB-IF used it as the foundation for USB4. USB4 tops out at 40Gbps as well, and it's backward compatible with Thunderbolt 3 devices.

Thunderbolt 4: The Polished Upgrade

Thunderbolt 4, released by Intel in 2020, is an upgraded version of Thunderbolt 3. It still runs at 40Gbps, but it raises the minimum spec requirements and ensures full feature completeness - things like dual 4K display support and PCIe accessory support are mandatory. Think of Thunderbolt 4 as the "enhanced, fully-loaded" version of Thunderbolt 3.

Which One Should You Choose?

If you're a regular user who charges a phone, transfers files, and occasionally connects a display, a full-feature Type-C cable at USB 3.2 Gen2 (10Gbps) is more than enough. If you have a MacBook or Thunderbolt-enabled device and need high-speed storage, eGPU, or professional docs, go with a USB4 or Thunderbolt 4 cable.

Important: For high-speed (40Gbps) cables longer than 1 meter, a built-in Retimer chip (active cable) is required - otherwise signal loss is too severe and speeds drop. When buying long high-speed cables, always confirm they're active cables.

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