USB4 is integrated with Thunderbolt 4. How is the new USB specification different from previous compatible buses such as Thunderbolt 4, Thunderbolt 3, USB-C, USB4, and USB3?
What’s Thunderbolt 4
Thunderbolt is a high-speed protocol developed by Intel that provides power and dynamically adjusts data and video bandwidth based on usage. It is now the basis of the USB4 specification.
Thunderbolt 4 and USB4 products will use the same underlying protocol specifications to improve the overall compatibility of USB-C-using products. However, TB4 (Thunderbolt 4) pushes USB4 to the next level by providing a more complete version of USB-C and superset features that USB4 doesn’t need.
What’s new with Thunderbolt 4?
First, Thunderbolt 4 will be USB4 compliant and maintain the industry-leading 40Gb/s performance of its Thunderbolt 3 predecessor. But there are some big changes.
➡️Dual-channel display interface
Thunderbolt 4 introduces and standardizes minimum host system requirements. It offers 40Gb/s, two 4K monitors or one 8K monitor, and 32Gb/s PCIe data on all ports, effectively doubling the minimum expected value of Thunderbolt 3.
For example, the MacBook Pro (13-inch, 2016, four Thunderbolt 3 ports) has two 40Gb/s ports on the left and two 20Gb/s ports on the right. This means that specific ports limit PCIe speeds to 16Gb/s and support only one 4K display. For Thunderbolt 4, this is not allowed – all four ports are required to be 40Gb/s.
Thunderbolt 4 will also extend end-to-end solution capabilities
- Accessories with four Thunderbolt ports
- Universal 40Gb/s cable up to 2 m
- The required PC charging power is up to 100W on at least one port
- Computers needed to “wake up from sleep” when connected to Thunderbolt Dock
- Required direct memory access (DMA) protection
What are the differences between Thunderbolt4 and Thunderbolt3?
In addition to the expanded features listed above, Thunderbolt 4 still requires mandatory certification of all shipped computers, accessories, and cables for a consistent user experience, regardless of product or manufacturer. It will also maintain compatibility with USB 2.0, USB 3.2, USB4, DisplayPort, and PCIe.
➡️Thunderbolt 4 is always 40Gb/s
Over the years, we’ve seen USB data rates increase from 5Gb/s to 20Gb/s, and USB4 speeds can reach 40Gb/s. However, unlike the USB4, its top speed is optional, and Thunderbolt requires it.
➡️Simplified computer ports
One port for all your needs! Well, at least the mark. Gone are the days of jumbled symbols on accessory ports that look like the same connection. Instead of this:
In Thunderbolt 4, you only see a Thunderbolt logo, and you know that it works with any supported protocol.
➡️Simplified the cable
Thunderbolt 4 cables will also be universal, replacing all different cables with a simple Thunderbolt logo and the number “4”.