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by PaulKeeble 60 days ago
USB is just a complete mess. I don't mind so much ports having different capabilities if they are well documented in the specification sheets of the hardware because then at least I can find out what they are capable of, but alas it never seems to be the case. Its very hard to work out whether a port can do Displayport and to what extent/performance or its true power capability or just its real data transfer speed. More often than I like I have just hoped that something works. Anything above 5W charging and 5gbps transfer is optional.
2 comments

I have an Intel NUC where 10 Gbps devices can run faster when plugged into the 3.1 Gen 2 ports than the Thunderbolt 3 ports under NVMe load, due to the former having dedicated PCIe lanes and the latter sharing the PCH lanes with the M.2 slots, which could be highly relevant if I were doing heavy disk I/O over a 10 Gbit Ethernet adapter.

This is more than a mild annoyance in the case of faster Thunderbolt devices like eGPUs, especially since, in addition to the 2 PCIe lanes dedicated to the USB ports and a third dedicated to an SD card slot, an additional five lanes are unused.

IIRC there was a reason at one point that Intel insisted on connecting Thunderbolt controllers through the PCH, but I don't understand why they didn't at least use four lanes for one of the M.2 slots. Sure, they may have had to move the SD card slot due to configuration limitations, but in what world is SD card performance more important than NVMe performance?

Probably cheaper and freed up PCIe lanes for desktop boards (marketing?) now yeah it doesn't make a lot of sense.
USB is just a complete mess.

You have to go out of your way to make Apple's Lightning connector look sensible, but somehow the USB consortium has managed to do it.

To be fair, lightning only looks sensible because it never did anything other than USB2 and power delivery.
A few devices do support USB 5Gbps over Lightning!
I miss lightning. Cleanable with a toothpick and some compressed air. The USB-C port on my current iPhone is now compacted with pocket lint and I can't seem to clean it out.
It had a pretty bad flaw: the spring contacts being on the device side, causing wear and tear there.

USB-C moved those to the much cheaper to replace cable. The little strip in the middle makes cleaning a bit harder but does provide for more longevity. It's s necessary evil in order to have the spring contacts on the plug side as well as not having them exposed to touch.

I think the plug side of USB is pretty well designed. The problem is more with the electrical and signalling side and the marketing of the different versions.

Toothpick and compressed air works for my phone.