Two of the most powerful cable types today, are USB4 and Thunderbolt 3, and they both use the USB-C connector. USB-C wasn't just a long-awaited release of a reversible, high-speed USB connection with advanced Power Delivery and DisplayPort support, it was also the death knell of a variety of different USB connections. It meant the industry could move towards one that was more unified and standardized than ever. USB4 is doing that once again, bringing an end to a variety of USB speeds and their various nomenclature. It also shares many specifications and features with Thunderbolt 3 and Thunderbolt 4.
Wondering how the USB4 vs Thunderbolt 3 battle stacks up? You’re not the only one. Is one faster than the other? Is Thunderbolt 3 still worth looking for in a new device, or is USB4 enough? What about Thunderbolt 4 and beyond?
We’ll answer these questions and more in this USB head-to-head.
USB4 vs. Thunderbolt 3 – The Differences and Similarities
The debate over USB4 vs Thunderbolt 3 isn't a complicated one, as both connectors share many of the same fantastic features. Both support a high data rate of up to 40Gbps (or around 5 GB/s), and both support charging up to 100W with USB Power Delivery. With charging and data horsepower, both are excellent options for charging everything from smartphones, right up to high-powered gaming laptops.
Both connectors are based on the USB-C standard, too, making them entirely reversible. They're also compatible with existing USB 3.2 devices and support the DisplayPort protocol for handling external displays.
USB4 is also backward compatible with Thunderbolt 3, letting Thunderbolt 3 cables work just fine on a USB4-equipped laptop or similar device. That isn't mandatory though, so it will be up to the laptop or device manufacturer to include that support.
Mode Lanes Speed Length
USB4 can come in several different modes ranging from 1 lane 10Gbps to 2 lane 40Gbps, with newer versions even offering 4 lane support up to 80 Gbps. Make sure to consult the device's specifications for this information, as all USB4 ports won't necessarily have the same specs.
USB 4 vs. Thunderbolt 3 – Which Is Which?
With a few functional and feature differences between USB4 and Thunderbolt 3, it's important to know which is which when buying a new device that may, and can, support both. Both standards use the USB-C connector, making them look rather similar at a quick glance. That said, Thunderbolt 3 connectors have a small lightning bolt logo next to them to help differentiate them.
While Thunderbolt 3 is always easily distinguishable by the logo, there is a lot more to look for with USB4. As seen below, USB-C ports should (but not always) have a speed rating designated next to the USB logo. For USB4, look for the USB logo with 40 or 80 before it.
USB4 vs. Thunderbolt 4
USB 4 and Thunderbolt 4 are very similar to one another, with similar core specifications and features, though there are some notable differences. Thunderbolt 4 doesn't upgrade the main features or specifications of Thunderbolt 3, but it does raise the bar for its support. Thunderbolt 4-supported devices must guarantee at least 32Gbps in PCI Express bandwidth to the port. The speed guarantee means all Thunderbolt 4-compatible devices support at least two 4K external displays or a single 8K display.
That guarantee is one area that Thunderbolt 4 can stand apart. Where it will mandate a high minimum standard for connection speed, USB4 devices can technically still be considered USB4 and support the more traditional USB 3.1 SuperSpeed+ connection of just 10Gbps, or USB 3.2 SuperSpeed++ 20Gbps (see our USB4 vs USB 4.0 section, below).
However, the USB4 specification was upgraded at the end of 2022 to potentially offer support for even greater data rates. The new specification introduces a new, higher-tier of USB4 cabling which can support data transfers up to 80 Gbps. That’s double that of the previous best USB4 and Thunderbolt 4 standards, making the new USB4 cables the most capable USB cables ever. They even rival the latest DisplayPort 2.1 standard for overall bandwidth when it comes to transmitting audio and video, and easily outstrip the more mainstream HDMI 2.1 specification.
As with standard USB4 cables, there is no performance guarantee for just any USB4 cable – you need the specific ones rated for this performance to get it. The USB Implementer’s Forum has introduced a new USB80Gbps packaging logo, and a new 80 Gbps port logo to help differentiate the devices which support these higher-speed connections. The new cables also have 80Gbps labeling to make it clear what they can do.
Thunderbolt 4 and USB4 cables are entirely interchangeable, and are backward compatible with all previous generations of their respective technologies – that’s basically any USB-C port. Thunderbolt 3 cables also work with Thunderbolt 4 and USB4 connections, though only the highest-quality ones can offer the same kind of default performance as Thunderbolt 4. Older USB-C 3.2 connections will work with USB4 connections, but won't be able to offer the fastest 40 Gbps transfer speeds.
USB4 and Thunderbolt 4 both support power delivery up to 100W, making it possible to charge almost any supporting device using the connection. More importantly, though, where older USB-C 3.2 devices did not have to support the higher wattage options of USB Power Delivery, USB4-certified devices must qualify. That means that any USB4 or Thunderbolt 4 port will be able to charge any USB4-compatible device at full power delivery for the fastest charging.
Alongside the new 80 Gbps bandwidth for top-tier USB4 cables, there’s also a new tier for power delivery. On those 80 Gbps, some support USB Power Delivery at up to 240W, making them by far the fastest charging connection for any mainstream device. Not all new 80 Gbps cables will support such power delivery, though. Those have the 80 Gbps 60W label to denote their lower charging capacity.
USB4 vs. USB 4.0
USB naming schemes have been messy for years, but the advent of USB4 was supposed to change that. It has streamlined things a little, but some marketers are using this name change to market some products as USB4 compliant when that isn’t necessarily true.
USB4 is not the same as USB 4.0. Where USB4 is a copyright-protected name controlled by the Implementer’s Forum and held to a high standard. A USB 4.0 external drive, for example, doesn’t technically need to use a USB4 controller chip and can instead get away with using older technologies, while still marketing the drive as “USB 4.0.”
This isn’t a problem when it comes to Cable Matters cables and adapters. If we call something a USB4 drive or USB4 cable, you can rest assured that is exactly that and is built to the highest of standards and perfectly adheres to the USB4 specification.
Which USB4 Cable to Buy
USB4 cables are now available to purchase. Even if you do not yet have a USB4 device, now is a great time to purchase cables to future-proof your setup because USB4 cables are fully backward compatible with USB-C and even Thunderbolt 3.
Cable Matters also carries Thunderbolt 4 cables. These cables have the distinct advantage of also being fully capable USB4 cables – eliminating the need to purchase separate USB4 and Thunderbolt cables. They are perfect for devices compatible with both standards.
If you require a longer Thunderbolt 4 cable, an active cable is the way to go. It features an active repeater chipset to boost the signal.
The Future of Thunderbolt
Thunderbolt 4 is the most capable of all previous Thunderbolt standards, but what comes next? Intel has already hinted at its potential in the Thunderbolt 5 specification.
Thunderbolt 5 is set to make much greater leaps in performance than Thunderbolt 4. The new standard is said to be capable of up to 80 Gbps bi-directional bandwidth – that’s as fast as the absolute fastest of USB4 cables. But that’s not all. Intel also claims that Thunderbolt 5 will be capable of as much as 120 Gbps of uni-directional bandwidth. That means that in special cases, like when streaming to ultra high-definition displays, Thunderbolt 5 will be able to offer even more available bandwidth.
This has the potential to make Thunderbolt 5 not only the most capable USB connection when it comes to transmitting video, but it would be the most powerful of any consumer cable. Better than HDMI 2.1. Better even, than the new DisplayPort 2.1 – and by quite some margin.
Thunderbolt 5 cables will also double the PCIe bandwidth, so external drives and graphics cards will be able to leverage even higher data rates for faster data transfers and better support for high-end graphics cards on lightweight laptops.
Additionally, Thunderbolt cables are held to such a high standard of quality, that existing passive Thunderbolt 4 cables under one meter in length will be Thunderbolt 5 compatible right from the get-go. You’ll still need devices, displays, and accessories that support Thunderbolt 5 to take full advantage, and unfortunately, those don’t exist yet. Still, when they do, Cable Matters’ range of high-quality Thunderbolt 4 cables should work just fine from day one.