www.thunderbolttechnology.net
For full compatibility a Thunderbolt™ device should be plugged into a Thunderbolt computer port. Some functionality may be available over a USB-C port depending on its implementation, but cannot be guaranteed.
Are Thunderbolt™ 4 PCs backwards compatible with Thunderbolt™, Thunderbolt™ 2, or Thunderbolt 3 based accessories?Accessories built to Thunderbolt and Thunderbolt 2 specifications are not supported by Thunderbolt 4 PCs.
Accessories built to the Thunderbolt 3 specification are fully supported by Thunderbolt 4 PCs.
Are Thunderbolt™ 3 PCs backwards compatible with Thunderbolt™ and Thunderbolt™ 2 accessories?Yes, solutions and products built to Thunderbolt and Thunderbolt 2 specifications will work with most Thunderbolt 3 PCs via an adapter, except Intel platforms launched in 2020 and later such as 10th gen Intel® Core™ vPro® platforms, 10th gen Intel® Core™ desktop and mobile processors. See the following
link for information on specific launch dates for specific CPU skus.
The Apple Thunderbolt display was certified for Mac only and may not work properly when connected to Windows based PCs.Why did Thunderbolt™ 3 move to the USB-C connector? Thunderbolt 3 needed a new connector to achieve 40Gbps and fit into smaller form factor devices. With the USB-C connector allowing for alternate modes, it made sense to bring Thunderbolt to this connector and create a superset solution that supports both Thunderbolt and USB.
So it remains to be seen if a Avid hd native thunderbolt device would work over usb-c like provided by the Sonnet Mcfiver.
Thunderbolt requires intel thunderbolt chips being present in the machine. USB-C is just a connector. I assume the Sonnect card does not have the required Thunderbolt chip. Tho with USB-4 they plan on making thunderbolt available without requiring the thunderbolt chip...
So this stuff is like murky water.