About the only devices capable of saturating TB are PCIe SSDs, some RAIDs, and eGPUs. There are advantages to this, but my use of TB doesn’t really benefit from it. 4 integrated controllers means 4 retimers and more I/O pins dedicated to it. Their GPU design may give them the ability to free up lanes and I/O that would normally go to a dGPU in the 16” MBP.

They don’t have to ration PCIe lanes if they don’t want to. Moving to Apple Silicon gives them more options. But the 16” MBP logic board looks pretty crammed as it is, so I’m not terribly surprised here. They could have done 1-port-per-bus under Intel. It saves space on the logic board, and only requires 4x PCIe lanes to feed it, so you aren’t fighting for I/O from the CPU that is also needed for the 5300M in the 16” MBP. Since the controllers needed to be *very* close to the ports, and aren’t exactly small, Apple opted for the two-port bus controllers. A one-port bus controller, and a two-port bus controller. Intel offered two controllers up until recently. Or if they are either waiting or working on a chip that can be a retimer and port mux. I’m curious if Apple will add more on-die controllers, which eats die space, requires more I/O pins, and more retimer chips.

Thunderbolt is very sensitive to trace distances.ĪFAIK, there’s not yet a chip that can be both a port mux and a retimer for Thunderbolt. Which at least is in part because using on-die controllers means they need the retimer chips near the physical ports themselves. And since Intel is interested in more tight integration with their stuff, there’s a decent amount of stuff that Apple wouldn’t want or couldn’t use from a licensed Intel logic block. I agree that Apple likely did customize this controller though, since they’ve been deep enough in Thunderbolt up to this point to be rolling custom firmware on the Intel TB controllers they have been using. Apple would have likely started from some reference point and then made customizations, rather than designing from scratch. An Alpine Ridge TB3 controller for example, is practically a USB4 controller in all but name. This is a good example of “distinction without a difference” though. Really USB4 is: Mandated USB-C + Optional TB3.

USB 3.2 Gen 2x2 or whatever word salad they are calling it. You can get 20Gbps over USB-C using dual 10Gbps USB 3 streams. As already stated, USB4 doesn’t mandate Thunderbolt support.

Thunderbolt hub mac mini m1