Comment by c-linkage
2 years ago
I figure the reason the Apple USB-C cable has a complex PCB embedded in the head-end of the cable is to detect Apple-certified devices and ensure top speed only when paired with an Apple-certified cable. Both the device and the cable have to recognize each other as properly licensed devices, otherwise you get sub-standard performance.
Apple has denied this.
From their support page https://support.apple.com/en-us/HT213839
> The USB-C cable that comes with your iPhone supports charging and USB 2 speeds. If you want to use a USB 3 device, use a compliant USB 3 cable that supports 10Gbit/s.
Note that this is only the 15 Pro. The "vanilla" 15 uses last year's A16 SoC and doesn't have a USB 3.x-capable PHY.
No.
Doing 40Gbps data is really hard because physics. Once you get beyond about 100cm, the signal loss basically requires you to add a repeater or retimer. This has been part of the USB-C specification since the very beginning, and any cable of this length doing 40Gbps will feature a similar PCB.
Sure, but I'm trying to do 10 Gbit/s on a <1m cable. That's definitely possible passively.
The USB specs say that C-to-C cables need an e-marker for that, and A-to-B or other non-C-to-C cables need nothing at all (apart from one or two resistors in case of an A-to-C or C-to-micro-B adapter).
If that were true, my fairly cheap ($10) newer cable also shouldn't work at 10 GBit/s, but it does.