Everything You Need to Know About Thunderbolt 4 & USB Type-C Cables

OWC Adam • Mar 12, 2021

thunderbolt 4 cable

OWC's Thunderbolt 4/USB-C cable is a universal cable that provides full capability for all Thunderbolt 3, Thunderbolt 4, USB-C, and USB4 devices. This backward-compatible cable replaces the Thunderbolt 3 cable and takes all the guesswork out of identifying the cables you need for your technology setup.


HERE ARE SOME HIGHLIGHTS OF OWC THUNDERBOLT 4 CABLES:

  • 100% USB-C Compatible: Connect to Macs, PCs, iPads, Chromebooks, Surfaces, and other devices with a Thunderbolt 3, Thunderbolt 4, USB-C, or USB4 port
  • Certified for All Uses: Enjoy lab test certified safe power delivery up to 100W, up to 40Gb/s of data performance, and up to 8K of video capability
  • Versatile Connections: Connect to millions of docks, displays, eGPUs, PCIe expansion, external SSDs, RAID storage, and other accessories
  • Powerful: Certified safe delivery of up to 100 watts of power/charging from docks, adapters, and other devices
  • Stunning Visuals: Connect up to 2x 4K displays or an 8K Thunderbolt or USB-C display
  • Guaranteed Quality: 3 Year OWC Limited Warranty

This innovative solution is lab-tested and certified with 100% universal USB-C compatibility and performance. Whatever device you use to do your thing, Type-C to Type-C connection solution ensures you’ll always have the right cable that simply works.

But what is the difference between USB-C, Thunderbolt 3, Thunderbolt 4, and USB 4? Can Thunderbolt 3 devices be connected using a Thunderbolt 4 cable, and vice versa? What happens when you use a Thunderbolt 3 cable to connect a Thunderbolt 4 Hub/Dock to a host?

We will try to answer some of these questions here.

What are USB-C, Thunderbolt 3, Thunderbolt 4, and USB 4?

USB-C is a connection type. USB-C is not Thunderbolt 3, Thunderbolt 4, or USB4. It is just the connection that those technologies use. To understand the difference between each of the aforementioned technologies, you have to look beyond the USB-C connector that each solution uses to plug in.

thunderbolt 4 connect everything ports scaled

Thunderbolt and USB4 are a communication standard or protocol. They provide a set of features for a computer to interact with devices through its USB-C connection. Thunderbolt 3, 4, and USB4 are basically 3-in-1 wrappers that tie PCIe, USB 3, and DisplayPort standards into a single do-it-all package. All three of these technologies use a USB-C connection to connect to computers and devices.


What is the difference between Thunderbolt 3, Thunderbolt 4, and USB 4?

Thunderbolt 4 guarantees certain specifications that are optional with the Thunderbolt 3 standard. Thunderbolt 4 is always 40 Gigabits per second, while Thunderbolt 3 and USB 4 can operate at either 20 or 40 Gigabits per second.

The difference between Thunderbolt 3 and USB 4 is mostly in the name. The actual standards are very similar, though there are some exceptions like signal frequency. For example, Thunderbolt 4 is 10.3125/20.625 Gbps while USB4 is 10/20 Gbps.

With Thunderbolt 3, PC users were often limited in features, whereas Apple provided full Thunderbolt 3 feature set support. PC users regularly lacked the full 40 Gbps, couldn’t support multiple displays or deliver power. Fortunately, with today’s Thunderbolt 4 standardization and certification, PC users get the full feature stack that Apple users got with Thunderbolt 3.


New Thunderbolt 4 features

Thunderbolt 4 does add some new features, too (both host and device-based), such as:


Host

  • Where Thunderbolt 3 was required to support only one external 4K monitor, now every Thunderbolt 4 laptop has to support up to two 4K displays or one 8K display.
  • Thunderbolt 4 now ensures that you can wake a computer with the shake of a mouse or the tap of a keyboard on Thunderbolt 4 docks. This wasn’t always the case with Thunderbolt 3.
  • Thunderbolt 4 is also a more data-safe technology, as it requires Intel VT-d-based direct memory access (DMA) protection, also known as DMA remapping.
  • Thunderbolt 4 requires storage speeds up to 3,000MBps, which is double the minimum requirements of Thunderbolt 3. With Thunderbolt 4, you will have all four lanes of PCI Express available – so PCIe can use up to 32Gbps of the total 40Gbps Thunderbolt bandwidth. With Thunderbolt 3, depending on your laptop manufacturer and model, some would only see 16Gbps of PCIe bandwidth.


Cable + Device

  • Another advantage of Thunderbolt 4 is that cables can be up to 2 meters long and still handle 40Gbps bandwidth and DisplayPort capability. Previously, passive Thunderbolt 3 cables had to be less than 1 meter to handle full bandwidth and support DisplayPort.


Device

  • You’ve always been able to “daisy chain” Thunderbolt devices, but with Thunderbolt 4 hubbing, you can now have up to four Thunderbolt ports in a hub or dock – each in a separate “branch” that can be disconnected without affecting any of the other Thunderbolt devices connected in other ports. [Check out the OWC Thunderbolt 4 Hub.]


HERE IS A SUMMARY OF THE MAIN DIFFERENCES:

Thunderbolt 4

Thunderbolt 3

USB4

USB3

Signal Bit Rate

10.3125G/20.625G/10G/20G

10.3125G/20.625G

10G/20G

10G

One Universal Computer Port

Yes

Yes

X

X

Universal 40Gbps cable (up to 2 meters in length)

Yes

No
> 0.7 m requires active cable[1]

X

X

Up to 4 ports for Hubbing

Yes

X

Yes

X

Speed (Host Min. Requirement)

40Gbps

20Gbps

20Gbps

10Gbs

Video – up to

2x 4k display or 1x8k (@60Hz)

1x 4k display

1x 4k display

1x 4k display

Data – up to

PCIe (32 Gbps)
USB 3.2 (10Gbps)

PCIe (16 Gbps)
USB 3.2 (10 Gbps)

USB 3.2 (10 Gbps)

USB 3.2 (5 Gbps)

PC Charging on at least 1 computer

Yes

X

X

X

PC Wake from Sleep

Yes

X

X

X

Minimum Port Power for Accessories

15W

15W

7.5W

4.5W

Thunderbolt Networking

Yes

Yes

X

X

Mandatory certification for shipping computers, cables and accessories

Yes

Yes

X

X

Cable testing audits

Yes

Yes

X

X

Intel VT-d based DMA protection

Yes

X

X

USB 4 Specification

Compliant

Compatible

Compliant

Compatible

Notes:

  1. Thunderbolt 3 cables longer than 0.7 meters are active cables which do not support DisplayPort
  2. There are different Thunderbolt 3 cable types – 20Gbps, 40Gbps, Active, Passive, 60W, 100W
    • Less than 1 meter: Passive, 40Gb TB3, USB 10Gb, DisplayPort, works with USB-C display directly
    • 1 meter and greater:
      • Passive: 20Gbps TB3, USB 10Gb, DisplayPort, works with USB-C display directly
      • Active: 40Gbps TB3, USB 480Mb, DisplayPort, DOES NOT work with USB-C display directly
  3. DisplayPort differences
    • Thunderbolt 4 – DisplayPort 1.4 (HBR3) supported up to 2 meters with passive cables
    • Thunderbolt 3 – DisplayPort supported with passive cables (less than 1 meter) but active cables (1 meter or greater) do not carry DisplayPort signal and won’t work to drive a USB-C display


Connecting Thunderbolt 3 Devices with Thunderbolt 4 Cables or vice versa

Thunderbolt 3 capable devices can be interconnected using a Thunderbolt 4 cable. Since Thunderbolt cables are backward compatible, users can expect Thunderbolt 3 performance from this connection.


But what happens when you use a Thunderbolt 3 cable to connect a Thunderbolt 4 Hub/Dock to a host?

In some instances, and depending on the devices being connected, you may not see any issues at all. Some specifications that were optional with Thunderbolt 3 are now guaranteed to work with Thunderbolt 4 – so your device may or may not work with a Thunderbolt 3 cable. Or in other instances—for example with active cables longer than 1 meter—you will see display issues and may not have full Thunderbolt 4 feature support.

Regardless of whether the device is USB 4, Thunderbolt 3, or Thunderbolt 4, it’s best to purchase a Thunderbolt 4 cable to guarantee full compatibility.


Why should you buy OWC Thunderbolt 4 /USB-C cables?

OWC has earned a reputation as the leading developer of Thunderbolt solutions through an unwavering commitment to quality. Each OWC Thunderbolt 4 / USB-C Cable is manufactured with premium materials and certified by multiple testing labs to ensure 100% reliability. Your complete satisfaction is guaranteed and each solution carries a 3-year warranty. Whether you’re a creative pro or performance enthusiast, OWC is the name you can trust to deliver the high-performance capabilities of your Thunderbolt and USB-C devices.

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