Thunderbolt 4 vs USB4

It may get confusing what the difference is between the two.

With the launch of Apple’s new M1 MacBook, we are introduced to a new connection standard listed as Thunderbolt/USB4.

So, what is this? Is it Thunderbolt 4? Is it some kind of Thunderbolt-USB hybrid? As if Thunderbolt 3 and the wide variety of USB connectors weren’t confusing enough with the many different features and speeds that range anywhere between 5Gbps and 40Gbps.

Calm down, fellow Mac fans; everything will make sense in a few minutes.

Thunderbolt3 - USB 3 MacBook
(Image Credit: Apple Insider)

If you check the new MacBook tech specs, you’ll see that Apple didn’t include a Thunderbolt 4 port but two Thunderbolt/USB4 ports. Many people read this and think that they’re getting a Thunderbolt 4 and a USB4 port. These are two different connectors, yet similar at the same time.

Don’t worry; your confusion is understandable because Thunderbolt 3, Thunderbolt 4, and USB4 look precisely the same since they use the same USB-C connector type. However, there are some differences between Thunderbolt 4 and USB4, so let’s clear the air once and for all. 

What is USB4?

First of all, this is not a typo. The development team got rid of the space in “USB4.” Secondly, USB4 is, in essence, an open-source Thunderbolt port, though a little different.

The story begins with Intel’s change in direction with their proprietary Thunderbolt technology. Intel released the Thunderbolt 3 protocol to be used in the development of the next-gen USB4 interface. As a result, Thunderbolt 4 and USB4 are closely related, and their future is intertwined.

This doesn’t mean we’ll stop seeing Thunderbolt ports. Intel is pushing the new Thunderbolt 4 interface with their 11th Generation Core processors, known as Tiger Lake, and they’ll continue to develop this technology.

Together with Apple’s M1 Macs, the same processors are also opening the world to USB4 connectivity. But keep in mind that the M1 Macs are sticking to Thunderbolt 3, which will achieve the same speeds as Thunderbolt 4. Mac users won’t feel the difference, but it’s a game-changer for PC users.

The Key Differences between Thunderbolt 4 and USB4

Thunderbolt 4 Intel
(Image Credit: Intel)

As mentioned earlier, it’s easy to confuse USB4 and Thunderbolt 4 because they use the same type of connector, and both achieve a maximum data transfer rate of 40 Gbps. Furthermore, Thunderbolt 4 supports USB4 connections.

This means that you can connect a USB device to the Thunderbolt 4 port. It’s also worth mentioning that Thunderbolt 4 is backward compatible, which means you can connect Thunderbolt 3 devices using the same port. All three connections are interchangeable; however, there’s a catch. You might experience slower speeds when connected to the USB4 port.

Why? Aren’t they both supposed to offer a speed of 40 Gbps?

Well, yes, but the trick is to look at the minimum requirements instead of maximum potential. Both connectors can achieve a data transfer rate of 40 Gbps. However, Thunderbolt 4 guarantees that speed because that’s the minimum requirement and the maximum speed.

On the other hand, USB4 ensures that speed only if you get the best version. USB4 comes in two flavors, much like Thunderbolt 3: a slower 20 Gbps version and a fast 40 Gbps version. Another key difference is that Thunderbolt 4 guarantees you can run at least two 4K displays, while on USB 4, you are guaranteed one 4K display.

As for USB4 docking systems, you won’t get wake-from-sleep and mandatory charging improvements that Thunderbolt 4 brings to the table. This might be a minor inconvenience to some.

USB4
(Image Credit: Cable Matters)

That being said, USB4 comes with a slight advantage over Thunderbolt 4 – you get informative logos next to the ports. This may seem like a small detail, but you’ll be able to quickly tell whether a device has a USB4 20Gbps or USB4 40Gbps port.

Intel doesn’t give us this much information upfront with the Thunderbolt ports. The lightning bolt logo doesn’t say much, so without reading the tech specs of particular laptops, you won’t even know whether you’re getting Thunderbolt 3 or 4.

All in all, Thunderbolt 4 and USB4 are pretty similar, and getting either of them will improve your experience.

Final Thoughts

As a Mac user, you won’t notice the lack of Thunderbolt 4. This upgraded interface is a game-changer for PC users due to many manufacturers that equipped their laptops and PCs with the weaker 20 Gbps version of Thunderbolt 3. Macs rely on the fast 40 Gbps Thunderbolt 3 ports and the new USB4 connectors that achieve the same speeds.

We don’t know yet whether we’re going to see Thunderbolt 4 Macs any time soon but rest assured, you won’t have to worry about performance and compatibility issues. You can continue using Thunderbolt 3 devices for the foreseeable future and enjoy the power and versatility of USB4 ports.

If you feel that you are pretty confident in your knowledge of USB4 and Thunderbolt 3, but are confused about Thunderbolt 4, take a look at our article on Thunderbolt 3 vs. Thunderbolt 4.