Let Lyle Warnke with Intel explain the new features in Thunderbolt 4. He previews the new Tiger Lake Laptop and the new Thunderbolt 4 Docking Port.

Thunderbolt 4
Supports the full speed of 40Gb/s with cables of up to 2m in length
Supports two 4K displays instead of one (or one 8K display)
At least one port must provide 100W power for laptop charging
Thunderbolt 4 docks must support wake from sleep

Must offer DMA protection against Thunderspy attack


USB4 Specification Compliant
o Most complete and future proof version of USB-C Effortless Connectivity 
o More ways to connect accessories than ever before Secure & Manageable
o Intel VT-d based DMA protection Always Fast
o 40Gb/s for connecting to powerful Thunderbolt docks, monitors, fast storage and more Notebook Charging 
o Required on at least one computer port Mandatory Certification
o Consistent user experience across a wide range of product types and manufacturers