Thunderbolt 4 vs. Thunderbolt 3 vs. USB4 vs. USB 3: Everything you need to know about the differences

If you’re looking for a new laptop or some wired accessories, you’ve likely come across a slew of different names for what appears to be the same item. With Thunderbolt 4 gradually replacing Thunderbolt 3 and USB4 gaining popularity as the next significant USB specification, the names have become a confused muddle. We evaluate and contrast all of these technologies and characteristics so you can get exactly what you need.

Thunderbolt 4 is replacing Thunderbolt 3.

Thunderbolt is a separate technology created by Intel with Apple’s assistance. Intel has been pushing Ultrabooks ahead since 2011, and it’s more of a brand name than a specification. Thunderbolt 3 uses the USB-C connector and includes USB 3.1, DisplayPort 1.2, and PCIe in a single cable. As a result, it can connect monitors, accessories, external storage, and a variety of other devices.

Thunderbolt 4 has replaced Thunderbolt 3. It supports the latest USB4 protocol, as well as DisplayPort 1.2 and PCIe. Thunderbolt 4 is also backwards compatible with all Thunderbolt versions (with the appropriate adaptor for Thunderbolt and Thunderbolt 2) and USB.

The successor retains the adaptable USB-C physical factor and a bandwidth of 40 Gbps. However, compared to Thunderbolt 3, many of its features and minimum performance levels have been improved.

Thunderbolt 4 now supports at least two 4K displays at 60Hz or one 8K panel at 30Hz, which is a significant improvement. Thunderbolt 3 can support two 4K monitors with the appropriate arrangement, however to be named Thunderbolt 3, it must support at least one 4K display.

Thunderbolt 4 requires twice as much PCIe bandwidth as Thunderbolt 3, which is increased to 32Gbps from 16Gbps. If you frequently utilize detachable storage, such as one of our best external hard drives, Thunderbolt 4 should provide theoretical transfer speeds of up to 3,000MB/s. Anyone who utilizes an external GPU to turn their Ultrabook into a gaming machine will benefit from the additional bandwidth.

The finest Thunderbolt 4 docking stations enable up to three downstream Thunderbolt 4 ports, as well as Direct Memory Access (DMA) protection with Intel’s Virtualization Technology for Directed I/O (VT-d) to combat attacks. If you have a desktop configuration, all you have to do is touch the accessories to wake up your computer. Thunderbolt 4 will accept cables up to two meters in length, with support for longer lines promised in the future. Laptops with charging ports that are less than 100W must have at least one charging port.

The basic line is that Thunderbolt 4 laptops can provide superior port performance. Thunderbolt 3 is still a great option that can do a lot, but investing in Thunderbolt 4 is the way to go if you want the best option for the future.

The next high-performance USB specification is USB4.

The USB Implementers Forum has designated USB4 as the next update to the Universal Serial Bus (USB) specification (USB-IF). USB 3.1 Gen 1 became USB 3.2 Gen 1 and USB 3.1 Gen 2 became USB 3.2 Gen 2, respectively. A USB 3.2 Gen 2×2 standard with speeds up to 20 Gbps was recently released. Otherwise, the first two standards would have been 5Gbps and 10Gbps, respectively.

Do you see how perplexing this is? At the very least, the USB-IF added more understandable names. USB 3.2 Gen 1 is SuperSpeed USB, USB 3.2 Gen 2 is SuperSpeed USB 10Gbps, and USB 3.2 Gen 2×2 is SuperSpeed USB 20Gbps. USB4 is currently available, which is backwards compatible with USB 2.0.

Intel essentially gave away its Thunderbolt 3 rights to allow USB4 to be used without all of the licensing. Many of the features of USB4 are the same as those of Thunderbolt 3. Unlike USB 3.0, which has a maximum speed of 20 Gbps, USB4 has a maximum speed of 40 Gbps, similar to Thunderbolt 3. (and 4). While USB 3.0 is still available in both USB-A and USB-C versions, USB4 will only be available in USB-C.

Previous USB versions shared bandwidth across all connected devices and depended on data and video lanes with no crossover. With USB4, the lanes can be shared for any purpose, allowing you to reach the bandwidth limit with the best laptop docking stations, for example. USB4 will support dual 4K displays or a single 5K display, as well as charging at up to 100W. Similar to Thunderbolt 3.

The most important conclusion is that USB4 aims to standardize ports across devices. It’s past time to move to USB-C, which offers high-performance capabilities comparable to Thunderbolt 3.

What distinguishes Thunderbolt 4 from USB4?

There’s one more item to think about. USB4 comes in four different variants, but we’ll mostly be seeing USB4 Gen 2×2 and USB4 Gen 2×3. USB4 20Gbps and USB4 40Gbps are the respective brand names. Unlike Thunderbolt 3 and 4, which guarantee a specific level of performance, you’ll have to be careful which version of USB4 you choose.

There is no minimum display resolution support necessary, and USB4 merely needs to reach 20Gbps. Data must travel at least 10 Gbps over USB 3.2, but Thunderbolt 4 ensures 10 Gbps over USB 3.2 and 32 Gbps PCIe performance. For USB4, the minimum power need is 7.5W, while Thunderbolt 4 requires 15W. Of course, with USB4, you don’t get the Thunderbolt bonuses and warranties.

Thunderbolt 4 and USB 4 are backwards compatible, but only Thunderbolt 4 ensures the performance levels required by power users. In terms of licensing rights, USB4 is superior. If you want to utilize Thunderbolt 4, you’ll have to pay Intel, whereas USB4 is usually free to use.

Thoughts?

As the port scene continues to change, there’s a lot to absorb here. Will you go for Thunderbolt 4 right away or will you wait for USB4 or Thunderbolt 3? Please share your thoughts in the comments area.