Thunderbolt 4 and USB4 are much more likely to support the latest USB PD 3.1 standard that allows for maximum charging of 240W compared to USB PD 3.0 and Thunderbolt 3’s 100W. Previously, passive TB3 cables had to be 0.7m or under to handle full bandwidth. Other advantages of Thunderbolt 4 include that hubs and docks can now have more than two Thunderbolt ports (up to four) and that TB4 cables can be up to 2 metres long and still handle the 40Gbps bandwidth. With Thunderbolt 3, depending on your laptop manufacturer and model, some implementations offer only 16Gbps of PCIe bandwidth. With Thunderbolt 4, you’re assured to have all four lanes of PCI Express available-so PCIe can consume up to 32Gbps of the total 40Gbps Thunderbolt bandwidth. Here we are talking about the portion of total Thunderbolt bandwidth allocated for PCI Express data transfer. Faster PCIe is important if you frequently transfer very large files between storage devices. Some of the early Thunderbolt 3 MacBooks had less bandwidth available on the right-hand-side Thunderbolt ports. What else? Well, Thunderbolt 4 requires PCIe (peripheral component interconnect express) at 32Gbps for storage speeds up to 3,000MBps, which is double the minimum requirements of Thunderbolt 3, although Apple’s recent MacBooks did have this already. TB4 is also a more data-safe technology, as it requires Intel VT-d-based direct memory access (DMA) protection, also known as DMA remapping.

This is maybe why Apple isn’t specifically calling its Thunderbolt version 4, due to the M1 display limitation. This wasn’t always the case with Thunderbolt 3.

Thunderbolt 4 now ensures that you can wake a computer with the shake of a mouse or the tap of a keyboard on Thunderbolt 4 docks. In fact, Thunderbolt 3 was required to support only one external 4K monitor, whereas every Thunderbolt 4 laptop has to support two 4K displays or one 8K display.

Usb 2 vs usb 3 vs usb c