USB4 and Thunderbolt are both high-speed data transfer interface standards. They look very similar and have some similarities, but also some significant differences. In this issue, we will conduct a detailed comparison of these two latest data transfer interfaces.
1. History of both
USB4: USB4 is a new standard announced by the USB-IF organization in 2019, which aims to provide faster data transfer speeds and is compatible with the Thunderbolt 3 protocol.
Thunderbolt interface: Thunderbolt is a high-speed data transfer technology developed by Intel. It was first launched in 2011 and has gone through multiple versions. The latest version is Thunderbolt 4.
2. Connectors
USB4: USB4 supports the USB Type-C connector, which is a double-sided pluggable connector that can be plugged in and out from both sides.
Thunderbolt interface: Thunderbolt also uses the USB Type-C connector, so on a physical level, the two can use the same interface.
3. Data transfer speed
USB4: USB4 supports data transfer rates up to 40 Gbps, which is the same speed as Thunderbolt 3.
Thunderbolt interface: The latest version of Thunderbolt interface (Thunderbolt 4) also supports data transfer rates of 40 Gbps.
4. Display output capability
USB4: USB4 supports DisplayPort Alt Mode, which can transmit content from two 4K displays or one 8K display.
Thunderbolt interface: Thunderbolt also supports DisplayPort Alt Mode, and has enhanced support for display output in Thunderbolt 4, allowing up to four displays to be connected.
5. Power supply capacity
USB4: USB4 supports USB Power Delivery (PD), which can provide up to 240W of power output and support fast charging.
Thunderbolt interface: Thunderbolt also supports USB PD, which can provide up to 240W of power output and support bidirectional power transmission.
6. Protocol support
USB4: USB4 supports USB 3.2, DisplayPort 1.4, and PCIe 3.0, and is compatible with the Thunderbolt 4 protocol.
Thunderbolt interface: Thunderbolt not only supports DisplayPort and PCIe, but also adds support for USB4 in Thunderbolt 4.
7. Device connectivity
USB4: USB4 supports daisy chain topology, allowing multiple data transmission devices to be connected.
Thunderbolt interface: Thunderbolt also supports daisy chain, and Thunderbolt 4 allows up to four Thunderbolt devices to be connected.
8. Security
USB4: Although the USB4 standard itself does not include special security features, it can support encrypted communication between devices.
Thunderbolt interface: The Thunderbolt protocol has certain built-in security mechanisms, such as device authentication, to ensure that only authenticated devices can connect.
9. Software Support
USB4: Software support for USB4 is relatively simple, and most operating systems have built-in support for USB4.
Thunderbolt interface: Thunderbolt requires dedicated driver support, which may limit its compatibility on some platforms.
10. Bidirectional transmission
USB4: USB4 supports simultaneous transmission of data, video, and power.
Thunderbolt interface: Thunderbolt also supports these functions, but in Thunderbolt 4, these functions have been further optimized.
11. Compatibility
USB4: USB4 is backward compatible with USB 3.x and USB 2.0 devices.
Thunderbolt: Thunderbolt is also backward compatible, but an adapter or dongle may be required to connect non-Thunderbolt devices.
