Can you network 2 Mac’s together over Thunderbolt 4
The a Thunderbolt Standards web page seems to suggest that it is possible.
Not sure how to assign an IP address.
I am surprised that there is no more interest in this as a 40 Gb per second network would be awesome.
And expensive. Which, by itself, would probably explain the lack of interest.
Plus, there’s a lot of behind-the-scenes protocol stuff to make computer-to-“world” Ethernet work properly that I’m not even sure Thunderbolt has.
The only thing I can find about multi-computer Thunderbolt networks seems to indicate that the computers are daisy-chained, with the intermediate computers using two Thunderbolt ports - one in, one out - as a network bridge.
And that sounds both messy and error-prone. 
It would be awesome for sure, but is there a real need for such bandwidth over two computers for long term? I doubt, you might need it for initial file transfer, but for day to day operation, I don’t think that is a common use case.
A 40 Gbit/s network is absolutely useful but Thunderbolt has really stringent length limits (3m without a fibre optic cable) that kinda limit its utility.
Also, 40GbE exists (with adaptors available from Thunderbolt) so that’s probably what anyone who actually needed that much bandwidth would use.
Where can I buy the 40gbE Thunderbolt adapters.
Are you able to plug them into some sort of switch that can then go out to one gigabit per second ethernet if required.
Answered my own question.
God bless google.
Now to check price.
Have you seen it in action?
SSD on one Mac to SSD on another Mac must be blazingly fast. Almost like going to an internal local drive except for the IP overhead. No?
If you can get Thunderbolt to 40gbE, logically there’s no reason you can’t run them through a 40gbE switch. But you’re going to spend a small fortune on this project.
What’s the use case you’re trying to optimize here for, other than “cool”?
I’m retired so mostly just COOL.
1GbE to Qnap NAS is pretty slow.
Having to run large file copies overnight is a Pain.
I guess I’m going to look to see if I can find a 10 Gb card for the Qnap and for an adapter off of thunderbolt 4 to set up a 10 GB network.
I can’t afford to be really cool.
Yeah, you’d be much better off looking at an upgrade to 10GbE, which is something some consumers do use; use cases for 40GbE are generally “the faster transfers will easily save/earn me the cost of that adaptor”.
