USB-C vs. Thunderbolt: What's the Difference?

Thunderbolt and USB are two of the most commonly used connector cables. Although the ports look the same, there are significant differences between USB-C vs. Thunderbolt, so you should know which one you need support for before purchasing a new device.

USB-C vs. Thunderbolt: Overall Findings

USB and Thunderbolt (not to be confused with Lightning) are both protocols for transferring data and video. They have traditionally used different types of ports and cables; however, with the advent of USB-C, Thunderbolt and USB cables can utilize the same 24-pin oval port. The latest USB protocol, USB 4, is only available via USB-C.

Because Thunderbolt and USB-C cables and ports look alike, it can be difficult to tell them apart. Look for the Thunderbolt logo to identify Thunderbolt-compatible hardware.

Speed: USB-C Is Catching up to Thunderbolt

While USB 4 is capable of transfer speeds up to 40Gbps, older USB standards top out at about 10Gbps. Thunderbolt 3 and 4 both support 40Gbps transfer speeds, but Thunderbolt 4 boasts PCIe bandwidth speeds up to 32Gbps, which is double what previous iterations offered. Transfers via Thunderbolt will always be faster than USB-C connections, but the differences between the protocols are starting to shrink.

Support: USB-C Is Universally Supported

All Macs today support both Thunderbolt and USB-C. While most Windows computers now come with USB-C ports, not all PCs support Thunderbolt because Intel requires manufacturers to purchase a license. Thunderbolt connections also require extra hardware that raises the cost of devices.

All ports that support the latest versions of Thunderbolt (Thunderbolt 3 and 4) also support USB-C cables, but not all USB-C ports support Thunderbolt. When you plug a Thunderbolt cable into a USB-C port, it uses the USB protocol to transfer data. On devices with multiple ports, some may only support USB-C while others support both USB-C and Thunderbolt.

Compatibility: Thunderbolt Is More Versatile

USB-C now supports HDMI video output, but only Thunderbolt currently supports DisplayPort. An adapter is required to transfer audio via USB-C, but Thunderbolt natively supports video and audio. However, Thunderbolt requires an adapter for HDMI. Thunderbolt can also support DVI and VGA displays through the use of adapters.

USB-C is backward compatible with USB 2 and later, and Thunderbolt is backward compatible with all other versions of Thunderbolt, although adapters may be required. You can daisy chain up to six Thunderbolt and USB cables to each other, but you can't mix and match.

Final Verdict

It will take a couple of years for all manufacturers to adopt the latest standards for Thunderbolt and USB. That means consumers will have to pay close attention to the versions of USB-C a device can support. For example, a USB-C port that supports USB 3 will have much slower transfer speeds than Thunderbolt 3 or 4. However, if the USB-C port includes support for USB 4, then the performance difference will be much less noticeable.