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USB: Cables, hubs, and Thunderbolt

These days understanding “USB” is quite complicated, but here is a quick summary:

  • USB-A is the connector you’re used to.
  • USB-C is the new connector which can be plugged in any direction1.
  • USB defines the “connector” and the type of communication separately
  • Connectors
    • USB-A is the connector you’re used to
    • USB-C is the new connector. Some newer USB protocols are USB-C only BUT the minimum supported protocol is USB 2.0
    • USB-C Cables vary in features because just supporting low power and USB 2.0 doesn’t require much. Supporting the high speed data transfer and high power charging requires physically different cables and special chips inside the cable ends.
  • Protocol Versions
    • USB 2.0 is basically a given with any device these days.
    • Some support USB 3.0 and have a blue block or ss->
      • Thunderbolt is something Intel and Apple made which supports more advanced uses of USB

USB-C Link to heading

The connector is reversible. It also support higher power transfer.

Which cable you get matters. Cheap USB-C cables may charge your device slowly. Some may not let you transfer data, but most will. A cheap cable will probably only be able to use USB 2.0 speeds which Wi-Fi is much faster than these days.

You can also find cables which support extremely high data transfer or power.

“THE CONFUSING WORLD OF USB” - FABIEN SANGLARD (Jan 2021)

why usb-c ended up so confusing

Thunderbolt and USB4 Link to heading

USB4 supports all features of Thunderbolt 3. There is also now Thunderbolt 4 which supports even more things.

The best cables to buy are Thunderbolt 4 cables since they support all the previous features and also the new ones which require new devices which support Thunderbolt 4.


  1. USB-C is supposed to be “reversible” but it still requires the device to properly handle that some pins can be used for different things. Some devices, especially cheaper ones, require you to put the USB-C cable in a particular way. Some USB-C cables only support certain features if put in a particular orientation. These days it’s rare, but it is a known problem and why so many USB-C testers exist. ↩︎

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