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.

Editors' Recommendations

Anita George
Anita has been a technology reporter since 2013 and currently writes for the Computing section at Digital Trends. She began…
Confused about Core Ultra? We were too, so we asked Intel about it
Intel's new Intel Core Ultra badge.

It’s the start of something new for Intel: the Core Ultra era. With the launch of new Meteor Lake processors, Intel is ditching its old naming scheme for something new. Intel CPU names are going to start looking a little different, and you might be confused by what you see on a spec sheet. We’re here to get you up to speed.

At first glance, Intel is just dropping the “i” that has defined its lineup of CPUs for 15 years. There are a few new details in the naming scheme, though, and knowing them can help you navigate this new era for Intel.
The basics of Core Ultra

Read more
With the arrival of Core Ultra, a new era for Intel has begun
A tray of Intel Core Ultra CPUs.

Intel's Meteor Lake processors represent more than just a new generation. It's a fresh start for Intel -- a cycle it seems to find itself in every few years -- and the birth of the AI PC. Most importantly, it's a sign that Intel can deliver on its road map with a fresh generation of processors built on a new node.

Meteor Lake ushers in the Intel 4 node, which we first heard about nearly three years ago with the launch of 11th-gen CPUs. It also marka the start of the Core Ultra era of CPUs, along with a consolidation of Intel's massive mobile CPU lineup. Now, processors fit into two camps: U-series for thin and light laptops, and H-series for more powerful machines.

Read more
What is Thunderbolt 5?
Thunderbolt 5 cable plugged into an Aorus laptop.

Thunderbolt 4 is one of the fastest and most capable connection standards you can utilize today, but Intel has announced its successor: Thunderbolt 5, and it's very impressive. With promises of up to triple the bandwidth in some scenarios, support for ultra high resolutions and refresh rates, and even the potential for a resurgence in external graphics cards, there's a lot to be excited about with Thunderbolt 5.

Intrigued? Here's everything we know about Thunderbolt 5.

Read more