Is Thunderbolt 3 The Same as USB-C?

Thunderbolt 3 and USB-C became mainstream around the same time, the mid 2010s, which has led many people to think that the two are the same. In this post, we take a deeper dive into the two technologies and answer whether Thunderbolt 3 cables are the same as USB-C cables.

What Is USB-C

As we mentioned in our earlier post, USB-C refers to the type of connector. Many different standards can use a USB-C connector with some common examples being USB 2.0, USB 3.2 Gen 2 and also Thunderbolt.

There’ve been many different USB connectors prior to USB-C but the thing that users appreciate the most about USB-C is that it is symmetrical and there’s no need to flip the plug a couple of times before you can fit it into a connector.

USB-C supports different standards and technologies. For USB, it supports USB 2.0 all the way to the newest USB standard, USB4. What this means is that two different USB cables with a USB-C connector could have very different speeds depending on the USB standard of the cables.

Standard	USB 2.0	USB 3.0	USB 3.1	USB 3.2	USB4	Thunderbolt 3
Launch Date	2001	2008	2013	2017	2019	2015
Max transfer rate	480 Mbps	5 Gbps	10 Gbps	20 Gbps	40 Gbps	40 Gbps

What is Thunderbolt 3

Thunderbolt is a hardware interface that was developed by Intel in partnership with Apple. It combines PCI Express, DisplayPort and provides DC power in a single cable. While Thunderbolt 1 and Thunderbolt 2 used a Mini DisplayPort connector, Thunderbolt 3 and Thunderbolt 4 use a USB-C connector.

Prior to 2019, manufacturers had to pay a hefty royalty fee in order to incorporate Thunderbolt 3 in their products. That’s one reason why very few devices used it in the early days and were expensive to begin with. As of 2019, however, manufacturers no longer need to pay any royalties to Intel and Apple so expect to see more devices using Thunderbolt 3.

Apple products are where you will mostly find Thunderbolt 3 as well as GPU enclosures because of its fast transfer speeds. While it doesn’t match a direct pci express connection, it comes pretty close which is very important for graphics cards.

External GPU Case With Thunderbolt 3 Ports

Image	Product	Description	Ratings
	Sonnet eGPU Breakaway Box 750ex - External GPU Chassis	Supports Many of the Latest GPU Cards: AMD Radeon VII, RX, RX Vega, Pro W and Pro WX models; NVIDIA GeForce RTX series, TITAN, and Quadro models.	4.1 / 5
	Razer Core X Aluminum External GPU Enclosure	Boosts Thunderbolt 3 laptop performance with support for up to 3 slot wide PCIe full sized desktop graphics cards Windows: Supports NVIDIA or AMD Graphics Cards MacOs: Supports AMD Graphics Cards only	4.3 / 5

RAID storage devices are also switching to Thunderbolt because they need fast data transfer speeds to ensure that all of the data is synced properly.

Active vs Passive Thunderbolt 3 Cables

You may have come across the terms “Active” and “Passive” when shopping for Thunderbolt 3 cables. Passive cables are cheaper and can transfer data up to 40 Gbps if the length of the cable is less than 0.5 meters (1.64 ft). Active cables can potentially transfer data at speeds of 40 Gbps up to a length of 2 meters (6.56 ft) but they do cost more.

Unfortunately, there’s no good way of telling whether the Thunderbolt 3 cables are active or passive just by looking at them. Cables also tend not to be labelled so you need to refer to the packaging or the site that you bought them from.

How To Identify Thunderbolt 3 Cables

A Thunderbolt 3 cable is required to show the lightning bolt symbol logo in order to be certified. If someone is trying to sell you a Thunderbolt 3 cable without the logo, you should definitely be suspicious.

The Difference Between Thunderbolt 3 And USB-C

What’s the difference between Thunderbolt 3 and USB-C? That’s like comparing apples and oranges because USB-C simply refers to the connector while Thunderbolt 3 is a hardware interface / standard. It would be more accurate to compare Thunderbolt 3 with USB standards like USB 2.0, USB 3.x or USB4.

The following table shows a comparison of the speeds between USB standards that use a USB-C connector and Thunderbolt 3. What you would notice is that Thunderbolt 3’s maximum transfer rate of 40 Gbps is twice as fast as even USB 3.2. Only USB4 can match the speed of Thunderbolt 3 and it is not very common on the market as of 2022.

Will Thunderbolt 3 Cable Work On A USB Port?

It isn’t just the difference in speeds that you need to be concerned about. A Thunderbolt 3 computer port can support both Thunderbolt 3 and USB-C devices. On the other hand, a USB-C computer port can only support USB devices.

What this means is that Thunderbolt 3 devices require both a Thunderbolt 3 cable and a Thunderbolt 3 port on the computer. USB 3.1 cables will not work on Thunderbolt devices.

Summarizing Thunderbolt 3 vs USB-C

Thunderbolt 3 and USB-C fall under different categories. Thunderbolt 3 is a hardware interface which specifies the data transfer speed while USB-C only refers to the connector at the end of the wire. The term USB-C has nothing to do with data speed or charging ability. While data transfer speeds are what users normally focus on, it is also important to consider whether your devices and computer will be compatible with Thunderbolt 3 and USB-C.