Skip to main content

Digital Trends may earn a commission when you buy through links on our site. Why trust us?

What is Thunderbolt, and is it different from USB-C?

Thunderbolt is a type of hardware interface technology that is used to connect various devices to a PC. You’ve likely already seen Thunderbolt in the form of its distinctive ports and cables — the latest generations use the USB-C connector. That’s the quick definition. But if you’re here, you’re probably looking for a more comprehensive explanation of what Thunderbolt is, and why it differs from USB-C.

In this guide, that’s exactly what you’ll get: We’ll go over some of its current iterations and how they compare, how Thunderbolt is different from USB-C, how to identify Thunderbolt ports, and find out the latest on when Thunderbolt 5 will launch. Now let’s take a closer look at Thunderbolt.

Thunderbolt 3 vs. Thunderbolt 4

Close up of ports on a 2016 MacBook Pro.
Bill Roberson/Digital Trends

Since Thunderbolt was introduced in 2011, there have been a number of different versions of it. But these days, if you’re shopping for a device that features Thunderbolt’s use, you’re probably looking at Thunderbolt 3 and Thunderbolt 4.

Introduced in 2015, Thunderbolt 3 features a USB-C connector, a max transfer speed of 40GB/s, and up to 15W of power for running accessories. It can also support one 4K display and is compatible with USB4 specification.

Launched in 2020, Thunderbolt 4 is the latest version of its connection technology that’s currently available. Thunderbolt 4 still has the same max transfer speed as Thunderbolt 3: 40Gb/s, but it mandates that as the minimum, whereas for Thunderbolt 3, it’s not enforced. Like Thunderbolt 3, Thunderbolt 4 also has a USB-C connector and offers up to 15W power delivery for accessories. But that’s where the similarities between the two pretty much end.

Unlike Thunderbolt 3, Thunderbolt 4 can support two 4K displays and is rated as “compliant” for USB4 specification. Thunderbolt 4 also has double the PCIe SSD bandwidth speed (32 Gb/s) of Thunderbolt 3 (16 Gb/s).

Is Thunderbolt the same as USB-C?

Rear view of an iMac sitting on a white table next to a potted plant. A view in which you can see the iMac's selection of ports.
Dan Baker/Digital Trends

No. Though Thunderbolt has recently incorporated the use of USB-C connectors, they’re still different connection technologies. So just because Thunderbolt 3 and 4 ports are designed for use with USB-C connectors, not all USB-C ports are designed to support Thunderbolt.

Do Thunderbolt and Thunderbolt 2 accessories work with Thunderbolt 3?

Close up of white Thunderbolt cables on a white background.
Image used with permission by copyright holder

They can, but not without help. Thunderbolt 3’s USB-C connection isn’t compatible with devices based on Thunderbolt or Thunderbolt 2 without an expensive adapter.

How do I know if I have a Thunderbolt port?

There are two main ways to know: You can either see if there is a thunderbolt icon next to your device’s USB-C port or you can check your device’s tech specs online to see if it mentions Thunderbolt ports in the product description.

When will Thunderbolt 5 launch?

While Intel officially introduced Thunderbolt 5 in September 2023, the exact launch date for Thunderbolt 5 has not been announced yet. Thunderbolt 5-based products are currently expected to begin their release at some point in 2024.

We’ll update this section once we know more.

Anita George
Anita has been a technology reporter since 2013 and currently writes for the Computing section at Digital Trends. She began…
The 6 best detachable laptops in 2024
The Surface Pro 9 with the Type Cover keyboard lifted up.

Detachable laptops – or tablets with removable keyboards – are a popular alternative to traditional laptops. These devices are ultra-portable and versatile, allowing you to stow them in even the most cramped backpack. They also serve as both tablet and laptop, letting you make use of their touchscreen for notetaking or drawing before reattaching their keyboard to type up a lab report or presentation.

There are hundreds of detachable laptops to choose from in 2024, including powerful models from Microsoft, Apple, Dell, and ASUS. However, it can be hard to narrow down all the options, as many of them offer similar specs or identical designs.

Read more
The best laptop brands for 2024
best laptop brands hp spectre x360 13  2021 1

If you like to write, browse, game, or work in different parts of your home or office, one of the best laptops is a necessity in 2024. There are many to choose from, but you can first narrow your options by looking at laptops from the most established and respected brands.

Here's a list of the best laptop brands in 2024 to get you started.
Dell

Read more
The 6 best laptops for realtors in 2024
Asus Zenbook 14 OLED front view showing display and keyboard.

If you're a realtor, trying to find a good laptop can be just as challenging as finding the perfect home for your clients. Not only do you need something that looks professional and can withstand the daily demands of the modern work environment, but it also needs to be portable and durable. After all, there's a good chance you'll be lugging it around with you to your showings, so a clunky laptop simply won't cut it.

That means you'll need a laptop that's portable, reliable, responsive, and boasts a professional design that'll impress your clients. That's quite the checklist – but thankfully, there are plenty of great laptops for realtors that fit all these criteria.

Read more