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

There are many different types of connectors you might come across when it comes to PC components. Thunderbolt is one of the newer ones, and it shares some things with USB-C. Thunderbolt 4 in particular has a lot in common with USB4, but it's not the same thing.

What is a Thunderbolt port?

Thunderbolt was developed by Intel in conjunction with Apple. It was originally called "Light Peak" before being renamed "Thunderbolt". The first commercial product with Thunderbolt was the MacBook Pro in 2011.

Thunderbolt supports high-resolution displays and high-performance data in a single port, but it's not a connector type. For example, Thunderbolt 1 on the MacBook Pro worked with Apple's Mini DisplayPort ports, and later versions were USB-C based.

Thunderbolt 2 was introduced in 2013 and also used the Mini DisplayPort connector. It had double the transfer speeds of Thunderbolt 1 (20 Gbps). This allowed him to be able to transfer 4K video files while sharing in 4K on a monitor simultaneously.

Thunderbolt 3 was released in 2016 and eventually ditched the Mini DisplayPort connector. Instead, it switched to USB-C, which was becoming widely used. Thunderbolt 3 had transfer speeds of up to 40 Gbps.

This brings us to Thunderbolt 4, the latest version at the time of writing. Thunderbolt 4 is still USB-C based and can transfer data at up to 40 Gbps. However, with Thunderbolt 4, 40 Gbps is an enforced minimum. Other benefits include dual 4K monitor support, 32Gb/s PCIe SSD bandwidth speed, and USB4 standard compliance.

Why use Thunderbolt over USB?

The idea behind Thunderbolt was to create a way to send a video signal and data over a single cable. That's why Apple jumped on board, because Thunderbolt allowed it to minimize the number of ports on Macs.

Thunderbolt's ability to run multiple devices through a single port is also a plus. The daisy chain feature opened the door to Thunderbolt docks and hubs. With just one port, you can easily expand the functionality of a laptop.

Over time, Thunderbolt's advantages over USB have narrowed. Thunderbolt 4 and USB4 have a lot in common. The main differences are in the minimum requirements.

Thunderbolt versus USB-C

On the surface, Thunderbolt 3 and Thunderbolt 4 appear to be the same as USB-C. After all, they both use the same USB-C ports and connectors. However, this did not always been the case – and still isn't. A USB device will likely work in a Thunderbolt port, but it may not provide the same transfer speeds.

However, Thunderbolt 4 and USB 4 are fully compatible. USB4 is also backward compatible with Thunderbolt 3 and USB 3.2 and 2.0. As mentioned above, the main differences lie in the minimum requirements.

USB4 devices have a minimum of 20 Gbps, while Thunderbolt 4's minimum is 32 Gbps. Thunderbolt also doubles the minimum power requirements of USB4, reaching 15W.

Another difference is transfer speeds over different cable lengths. Thunderbolt 4 can transfer at 40 Gbps with cables longer than two meters, but USB4 requires a cable shorter than one meter for the same speeds. These lower requirements allow for cheaper USB4 accessories, but this comes at the cost of performance.

So how can you tell the difference? It's all about icons. Thunderbolt 4 devices are labeled with a lightning bolt icon and the number 4. USB4 devices have the standard USB icon with the number 20 or 40 (for Gbps). Unfortunately, ports, like on MacBooks, aren't always labeled with icons, so you'll need to check your device's specs.

In conclusion, Thunderbolt is one of many hardware interfaces for connecting peripherals to computers. It made it possible to share a screen and transfer data simultaneously, which was a big advantage over competing standards for a while. USB4 has largely caught up with Thunderbolt these days – and USB4 may get faster than Thunderbolt – but Thunderbolt still has a slight advantage if you can use it.