Thunderbolt 4 vs USB 4: What’s the Difference?

Thunderbolt 4 vs USB 4: What’s the Difference?
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In the previous article(Is the USB C Port on Your Computer Thunderbolt 3), we learned about the similarities and differences between the USB C interface and the Thunderbolt 3 interface and also mentioned some content of Thunderbolt 4. Here, we will understand the difference between Thunderbolt 4 and USB 4.


USB4 and Thunderbolt 4 are powerful and convenient. Both use USB Type-C as a unified interface and only need one cable to perform multiple functions such as screen display, charging, and data transmission.

Both in appearance and function, USB4 and Thunderbolt 4 have many similarities. It is not so easy to tell the difference between them.


USB 4.0

In 2019, the USB 4.0 version was announced, and it no longer has many confusing names like the previous version. Its transmission speed can support 20Gbps, and the maximum transmission speed has reached 40Gbps. Most importantly, USB4 only uses USB Type- C interface and must support PD and up to 100W. In addition, USB4 is also backward compatible with USB 2.0 and USB 3.2 and supports Thunderbolt 3/4.

ACASIS Blog - USB 4 vs Thunderbolt 4 What’s the DifferenceACASIS Blog - USB 4 vs Thunderbolt 4 What’s the Difference

(Image source: USB-IF Logo License – Trademark Requirements Chart)


The Evolution of Thunderbolt

Thunderbolt is a high-speed I/O interface developed by Intel in 2009. Its main purpose is to be used as a transmission cable between computers and other devices, hoping to replace and unify a large number of various interfaces on computers. Intel released the first generation of Thunderbolt in 2011, the interface is integrated with Mini DisplayPort, the transmission speed can reach 10Gbps, and up to six peripheral devices can be connected through the Daisy chain.

ACASIS Blog - ACASIS Blog-USB 4 vs Thunderbolt 4 What’s the Difference

(Thunderbolt 1 port and cable)


Thunderbolt 2, which was launched in 2013, has doubled the transmission speed to 20Gbps, and the interface is the same as the first generation, still using Mini DisplayPort. In 2015, Thunderbolt 3 was launched, and the transmission speed doubled again to 40Gbps. In addition, Thunderbolt has also made a major change in this generation, not only the interface is changed to USB Type-C, the maximum power supply is 100W, and it supports dual 4K video output or single 5K video output. It is precisely because of this decision to be compatible with USB Type-C that Thunderbolt 3 is more popular than Thunderbolt and Thunderbolt 2.

ACASIS Blog - ACASIS Blog-USB 4 vs Thunderbolt 4 What’s the Difference
(Thunderbolt 3 interface)

As for Thunderbolt 4, which was launched in 2020, the interface still uses USB Type-C. Although the maximum transmission speed is still 40Gbps, the bandwidth of PCIe has been upgraded from 16Gbps of Thunderbolt 3 to 32Gbps of Thunderbolt 4. Compared with PCIe devices such as external graphics cards, the transmission speed and performance of Thunderbolt 4 have been significantly improved. The charging power is still maintained at 100W.

ACASIS Blog - ACASIS Blog-USB 4 vs Thunderbolt 4 What’s the Difference

(Thunderbolt 4)


What is the difference between Thunderbolt 4 and USB 4?

Both USB4 and Thunderbolt 4 use the USB Type-C interface, the data transfer rate also supports 40Gbps, and both support video output and 100W power supply, so it is difficult to distinguish the two interfaces, so what is the difference between USB4 and Thunderbolt 4?

The most obvious difference between the two lies in the following points:

1.Supported Bandwidth

Both support up to 40Gbps, but USB4 has USB4 20Gbps and USB 40Gbps, so the minimum specification only needs 20Gbps, while Thunderbolt 4 has only one specification of 40Gbps.

2.Charging Power

Both support up to 100W, but the minimum standard for USB4 is 7.5W, while Thunderbolt 4 is at 15W.

3.Data Transfer Speed

As for data transmission, USB4 needs to support at least 10Gbps of USB 3.2, while Thunderbolt 4 not only supports 10Gbps of USB 3.2 but also can reach 32Gbps through PCIe.

4.Supported Monitor

USB4 only supports single display, and there is no minimum resolution requirement; in contrast, Thunderbolt 4 can support dual 4K 60Hz display or single 8K 60Hz display.

5.System wake from sleep

The Thunderbolt 4 interface also supports waking up from sleep, for example, when you want to wake up a computer with a mouse or keyboard, which will save users a lot of trouble.


In addition to the key points mentioned above, the following table sorts out the differences between the two in other aspects:

ACASIS Blog - ACASIS Blog-USB 4 vs Thunderbolt 4 What’s the Difference

In general, although the specifications of Thunderbolt 4 and USB4 are very similar, Thunderbolt 4 has higher minimum specification requirements than USB4 to ensure its basic functions, and Thunderbolt 4 is compatible with USB4. Conversely, USB4 is not necessarily compatible with Thunderbolt 4.


How to check whether your Apple device supports USB 4 or Thunderbolt 4 interface?

If you’re not sure whether your Apple device supports USB 4 or Thunderbolt 4, the following list has got you covered. You can also use the following steps to find out the port specifications of your Apple device.

1.Go to the “Apple Menu” and click on the “About This Mac” option.

2.Double click on your Mac’s serial number and copy it by pressing "Command + C".

3.Open the official Tech Specs page, and paste the copied serial number in the "Search Tech Specs" bar by pressing "Command + V".

4.Click on the "Search" button to see the port specification of your Mac.


The following Mac models come with the Thunderbolt 4.0 specification:

  • MacBook Pro 16-inch - 2021 Model
  • MacBook Pro 14-inch - 2021 Model


The following Apple laptops come with the USB 4 specification:

  • Mac mini M1 - 2020 Model
  • MacBook Air M1 - 2020 Model
  • MacBook Pro 13-inch M1 - 2020 Model
  • iMac 24-inch M1 - 2021 Model


In ACASIS, we have developed many products with Thunderbolt 3/4 interface. If you want to know about Thunderbolt SSD enclosure, please click Thunderbolt 3/4 SSD Enclosure; if you want to know about Thunderbolt docking station, please click Thunderbolt 3/4 Docking Station; if you want to know about Thunderbolt video capture card, please click Thunderbolt 3 Capture Card.


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