Research Hub > Thunderbolt 3 vs USB-C: What's Right for You?

September 06, 2022

4 min

Thunderbolt 3 vs USB-C: What's Right for You?

Here’s what you need to know when comparing USB-C and Thunderbolt 3 specifications for ports and cables and what’s right for you.

The USB-C and Thunderbolt 3 connective interfaces have brought on a new era of wide compatibility across major tech products, not to mention much faster charging and data transfer speeds than ever before. Here’s what you need to know when comparing USB-C and Thunderbolt 3 specifications for ports and cables and what’s right for you.

By looking at the port alone, you can’t tell the difference between a USB-C, Thunderbolt 3 and Thunderbolt 4 port—indeed, they all offer the same basic capabilities, physical appearance and are cross-compatible with the devices they support. These specifications differ mostly when it comes to transfer speeds, charging speeds and size.

In this article, we’re going to break down what makes USB-C, Thunderbolt 3 and Thunderbolt 4 technologies unique, and what you should consider when purchasing devices with these ports or buying cables for your devices.

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What is USB Type-C (USB-C)?

The USB-C (Universal Serial Bus Type C) is an oval-shaped connector with a 24-pin plug, descended from a long line of USB standards, each with unique shapes, sizes and pin configurations. USB-C cables can transmit both power and data.

After a storied history of changes, USB-C is becoming a standard charging and data transfer port amongst modern laptops due to its compactness (USB-C uses an 8.4mm connector versus USB-A’s 12mm), symmetrical design and higher transfer/charging speed compared to USB standards before it.

Today’s standard USB-C connector was created in response to the flaws of its most common predecessor, the USB-A 2.0 connector. You’ve no doubt noticed when attempting to plug in a USB-A port that it needs to be correctly oriented with the USB-A cable or else it won’t plug in since the USB-A pin connectors at the bottom of the plug need to be aligned to the receiver. In contrast, the receiver in a USB-C port sits in the center so the cable orientation does not matter, eliminating this annoyance.

USB-C Specifications and Transfer/Charging Speed

USB-C has three standard specifications, although the basic functionality remains the same. Before you buy a laptop, check exactly what kinds of USB-C ports it offers, particularly if you transfer a lot of data via USB-C cable or want to charge your USB-C-compatible accessories faster.

  • The USB 3.2 Gen 1 specification, also called USB 3.1 Gen 1 or USB 3.0, supports transfer speeds up to 5Gbps. This is about 10x faster than USB-A 2.0.

  • The USB 3.2 Gen 2 specification, also called USB 3.1 Gen 2 or USB 3.1, supports transfer speeds up to 10Gbps. This is about 20x faster than USB-A 2.0.

  • The USB 3.2 Gen 2x2 specification, also called USB 3.2, supports transfer speeds up to 20Gbps. This is about 40x faster than USB-A 2.0.

When it comes to charging speed, it all depends on what type of port the USB-C cable is plugged into. The default charging speed of a USB-C cable is the same as USB-A at 2.5 watts, but some devices have the “USB Power Delivery (USB PD)” specification, allowing for 100 watts of power transfer between devices.

What is Thunderbolt 3?

Like USB-C, the Thunderbolt 3 has a 24-pin, 8.4mm, reversible connector. However, Thunderbolt 3 is not a USB cable at all; it is a unique hardware interface standard developed by Apple and Intel. It does all the same things as USB-C but many times faster, plus transmit video and connect to monitors.

You won’t be able to tell any physical difference between a USB-C and Thunderbolt 3 connector; you’ll have to either refer to your device specs to know what kind of port(s) it has or look for a little lightning bolt symbol with a downward-facing arrow next to the port on your device or on the head of your cable. Most modern laptops offer a mix of USB-C and Thunderbolt 3 connectivity.

 No need to worry about cross-compatibility thankfully, as any USB-C cable can plug into any Thunderbolt 3 port and vice-versa. Thunderbolt 3 uses the USB-C standard as a backup if the connected device doesn’t use Thunderbolt technology; however, this will limit your data transfer speeds to USB-C level.

One of the major advantages of Thunderbolt 3 is the ability to support a range of adapters and protocols with its high data transfer speeds, such as USB-C to DisplayPort adapters for connecting dual 4K monitors or one 5K monitor, powered docking stations and eGPU (external graphics processing unit) enclosures for additional graphics processing power.

Thunderbolt 3 Transfer/Charging Speed

The Thunderbolt 3 cable doubles the max data transfer speed of USB-C, running as fast as 40Gbps. While it has a default charging speed of 15 watts (six times faster than USB-C’s default speed), if you connect your device with USB PD, you achieve about the same 100 watts of power as USB-C.

Thunderbolt 3 vs Thunderbolt 4

Thunderbolt 4 ports look identical to both Thunderbolt 3 and USB-C ports and have the same 24-pin connector. In fact, the Thunderbolt 4 hardware interface has the same transfer and charging speeds as Thunderbolt 3 and are cross-compatible. Most cables will have the arrowed lightning bolt with either the number 3 or 4 on the head of the cable, although this is not a standard. You’ll most likely have to check your device’s specs to see if it supports Thunderbolt 4.

The actual difference between Thunderbolt 3 and 4 lay in what the interface is capable of in terms of device support. Thunderbolt 4 can support dual 4K displays (like Thunderbolt 3) but can also power a single 8K monitor (versus 5K for Thunderbolt 3). Additionally, Thunderbolt 4 supports a minimum PCIe storage bandwidth of 32Gpbs to Thunderbolt 3’s 16Gpbs.

Which Port Should I Use: Thunderbolt 3, Thunderbolt 4, or USB-C?

If you’re not looking to transfer large amounts of data quickly or connect your laptop to multiple high-resolution monitors, you’ll find USB-C to be adequate for your needs. If you’re concerned about the slower charging speed, you can seek out USB-C PD-enabled devices. 


We hope this article was helpful in learning the nuances between USB-C and Thunderbolt technology. CDW sells a wide variety of cables and adapters, including USB-C and Thunderbolt. Find exactly what you need from the Experts Who Get IT.