So I realise they both have the same connectors, but that they operate using different protocols and different ciruitry inside the thunderbolt or USB based devices that are connected to one another with these cables, but I’m specifically wondering about the differences between USB-c and TB4 cables themselves. Why can’t you for example, connect a thunderbolt device to a thunderbolt port using a USB-C cable? (Or can you?) What’s different inside the cables which allows them to carry one signal over another despite still both using the same connector at either end of a cable?
USB-C it’s just a universal connection type. Thunderbolt 4 can use USB-C, but because of the requirements of thunderbolt 4 needs a compatible cable.
USB 4.0 actually has thunderbolt 3, by default. If we look at USB 3.0, 3.1, thunderbolt 3, etc. You’ll notice the numbers are all over the place. 5gbps, 10gbps, 20gbps, 40gbps and many computers in recent years still use USB 2.0 ports for peripherals.
Thunderbolt 4 tightened the reigns a little and made minimums that thunderbolt 3 didn’t enforce.
You MAY meet all of these numbers with high end thunderbolt 3 devices, but there was no guarantee until thunderbolt 4.
https://www.intel.com/content/www/us/en/architecture-and-technology/thunderbolt/thunderbolt-4-vs-usb-c.html
I guess what I mean is, is there something physically different inside a length of USB-C cable and a length of Thunderbolt cable. What makes a Thunderbolt 4 cable ‘compatible’? Are they physically drastically different despite the same connectors?
Shorter cable for fastest data transfer, probably using more wires for maximum bandwidth, thicker gauge wire for higher wattage. The biggest safety concern, would be trying to pass that 100w through wires that are too thin, and overheating/melting the cable.
I’m assuming these are also shielded more than a typical generic USB c cable to limit interference.
Some USB c cables, like USB micro, may not even have data connections inside the cable, if it was solely meant for charging purposes.
Long story short, you could probably use a non rated cable, and have some success. Thunderbolt 4 cable is going to give you the best signal, fastest possible data transfer, and highest wattage charging.
This is the same as cellphones getting rapid/fast charging. Suddenly all the cables got shorter and fatter, to accommodate the higher amperage through the wire. USB micro topped out at like 2amps, maybe 10 watts, but newer phones charge at like 80+watts.