Both Thunderbolt 4 and USB4 are based on the underlying protocol of Thunderbolt 3, and they are compatible with each other. In terms of interface form, Thunderbolt 4 and USB4 both use USB Type-C. Thunderbolt 4 is an upgraded and enhanced version of Thunderbolt 3. Although the transmission speed is still 40Gbps, it has improved in terms of video transmission and data transmission. For USB4, it is divided into two versions: USB4 20 version and USB4 40 version, and the transmission bandwidth is 20Gbps and 40Gbps respectively.
Intel officials have a more detailed description of the upgrades of Thunderbolt 4 compared to Thunderbolt 3:
· Video transmission: When an external display is connected, Thunderbolt 4 supports two 4K displays or one 8K display, while Thunderbolt 3 only supports one 4K display.
· Data transmission: When an external graphics card or hard disk is connected, the PCIe transmission speed is increased from 16Gbps to 32Gbps, and the transmission speed can reach 3000MB/s, which is closer to the performance when plugged into the motherboard.
Number of interfaces: Thunderbolt 4 supports 4 Thunderbolt interfaces, and 3 Thunderbolt 4 interfaces can be expanded through a single cable.
· Cable length: Thunderbolt 4 supports a cable length of 2 meters. In contrast, Thunderbolt 3 only supports a 0.7-meter cable, which is still an improvement.
Wake up from sleep: After connecting the Thunderbolt 4 docking station, you can wake up the computer from sleep by touching the keyboard or mouse.