- Thunderbolt 3 has adopted the USB-C format, so all Thunderbolt 3 ports are able to use ordinary USB-C cables.
- Thunderbolt 3 has higher performance requirements than USB-C, so not all USB-C cables are of sufficiently high quality to work at Thunderbolt speeds.
- USB-C does a lot of things other than Thunderbolt 3, including high-wattage charging using the Power Delivery (PD) standard.
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Thunderbolt is a connectivity standard that can transfer large amounts of power and data.
While older versions of Thunderbolt used the Mini DisplayPort connector, the latest version – Thunderbolt 3 – uses a USB-C-style connector.
So while all Thunderbolt 3 cables and ports use USB-C, not all USB-C connections are also Thunderbolt 3.
What you need to know about Thunderbolt connectivity
Because the USB-C connection is proving to be very popular, the latest version of the connectivity specification called Thunderbolt has formally adopted USB-C as its physical hardware. That means you can use any Thunderbolt 3 cable as a USB-C cable, and any Thunderbolt 3 port can use a USB-C cable.
But USB-C cables vary. Thunderbolt 3 can transfer data up to 40 Gbps – you can get this speed with official Thunderbolt 3 cables or a good-quality USB-C cable that’s less than about 1.6 feet in length. USB-C cables longer than 1.6 feet may top out at 20 Gbps, depending on their quality.
USB-C isn’t automatically Thunderbolt 3
USB-C has become incredibly popular, found in many phones, tablets, laptops, and other mobile devices. For the most part, USB-C cables and ports are not designed to be Thunderbolt 3, and so they will work as regular USB-C connections unless otherwise indicated.
USB-C can do a lot of things, including delivering power and charging devices, transferring data, audio, and even video. Depending on your device, USB-C may transfer data at USB 2.0 speeds of 480 Mbps (though that’s uncommon) or 5 Gbps or 10 Gbps (much more common). When it comes to bandwidth, USB-C is designed to deliver up to 10 Gbps if it’s not a Thunderbolt port.
But making this just a little more confusing, if the USB-C port is considered a Power Delivery (PD) connection, it can supply 100 watts of power, which is enough to run high-wattage devices like laptops.