USB4 takes over from the often confusing USB 3.0 to 3.2, offering either 20Gbps or 40Gbps data speeds. It uses the same rounded, reversible Type-C connector as USB-C, Thunderbolt 3 and 4.
A Thunderbolt 4 cable is also a USB4 cable, but not all USB4 cables will be certified for use with Thunderbolt 4 or even Thunderbolt 3—which is another reason that a TB4 cable is our universal recommendation.
USB4 has lower requirements than Thunderbolt 4 and doesn’t offer all the benefits such as support for dual displays, so its cables are often cheaper, acting more like Thunderbolt 3.
That said, USB4 is certainly more efficient than older USB variants at sharing between data and display protocols as it can dynamically monitor bandwidth requirements for connected displays and save the remaining bandwidth for data transfer. Older USB simply split the bandwidth in two for display and data.
USB4 can support Power Delivery up to 100W (PD 3.0) or 240W (PD 3.1). And, like Thunderbolt 4, USB4 is backwards compatible with USB 3.2, USB 3.1, USB 3.0, USB 2.0, and Thunderbolt 3.
A certified USB4 cable will feature the USB logo plus either the number 20 or 40 depending on the speed (20Gbps or 40Gbps) it is rated at.
USB4.0 HUB 40Gbps 4-in-1 hub
3*Thunderbolt3,data tranfer speed up to 40gbps (Video output
up to 8k 30hz or 2x4k @60hz PD 60w),downward compatible with USB2.0 USB3.0
1*usb-A 3.2 Gen2,data transfer speed up to 10gbps