Look around your house and chances are you have at least a few devices that use Universal Serial Bus. On average, some 3 billion USB ports are shipped each year, making it by far the most successful peripheral connection type in the world.

In fact, device manufacturers are so confident in the new USB-C standard that Intel announced last year that Thunderbolt 3, once thought to be a USB replacement, will use the same port type as USB-C. This means every Thunderbolt 3 port will also work as a USB-C port and every Thunderbolt 3 cable will work as a USB-C cable.

Before you can fully appreciate what a leap forward both USB Type-C and Thunderbolt 3 are, let's familiarize you with Type-A, Type-B, and the various versions of the Thunderbolt standard.

Thunderbolt

Prior to Thunderbolt 3, Thunderbolt 2 and the original Thunderbolt shared the same cable type and port (which is the same port type as Apple's Mini DisplayPort) and had top data transfer speeds of 20Gbps and 10Gbps, respectively. With these older Thunderbolt standards, the cable was active, meaning the cable itself is a device that requires power to operate (which is why most Thunderbolt 1 or 2 devices would require an external power source in order to function.) This made Thunderbolt a much more expensive solution, as the cable itself is some 10 times more expensive than a USB cable of the same length.

Thunderbolt revisions

Revision Year released Super set of Top speed Port type
Thunderbolt 2011 Mini DisplayPort 10Gbps Mini DisplayPort
Thunderbolt 2 2013 Thunderbolt 20Gbps Mini DisplayPort
Thunderbolt 3 2015 Thunderbolt 2 (adapter required,) DisplayPort, PCIe 3rd Gen, USB 3.1 40Gbps (short or active cable) 20Gbps (long, passive cable,) USB-C

Here's how Thunderbolt 3 is different from its predecessors:

  • The Mini DisplayPort connection type has been ditched in favor of a USB-C connection type.
  • All Thunderbolt 3 cables will work as USB-C cables.
  • All USB-C cables will work as Thunderbolt 3 cables as long as they are good quality cables.
  • Thunderbolt 3 has a top data transfer speed of 40Gbps as long as the cable is 0.5m (1.6 ft.) or shorter.
  • For 1m (3.2 ft.) or longer cables, Thunderbolt 3 supports passive (cheaper) ones that have a top speed of 20Gbps, and active cables (more expensive) that retain the 40Gbps speed.
  • Thunderbolt 3 is backward-compatible with earlier versions of Thunderbolt, but due to the new port type, adapters are required to use legacy Thunderbolt devices.
  • Any USB-C device (like a Google Pixel) plugged into a Thunderbolt 3 port will function normally.
  • Since Thunderbolt 3 devices use discrete Thunderbolt chips to function, they will not function if plugged into a USB-C port.

All versions of Thunderbolt allow for daisy-chaining up to six devices together to a host and in addition to data, can also carry Hi-Def video and audio signals.