
Now how many USB-C to USB-C cables are there? (USB4 Update, Sept 12, 2019) - sohkamyung
https://people.kernel.org/bleung/now-how-many-usb-c-to-usb-c-cables-are-there-usb4-update-september-12
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Dunedan
> A USB 3.1 Gen 1 cable built and sold in 2015 would have been advertised to
> support 5Gbps operation in 2015. Fast forward to 2019 or 2020, that exact
> same physical cable (Gen 1), will actually allow you to hit 20gbps using
> USB4.

I was prepared for most of the details, but that caught me by surprise. So you
can't trust what a cable is marked with or advertised for by its manufacturer,
but have to check every cable using software.

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diffeomorphism
I am not seeing why a cable performing better than marked/advertised (20
instead of 5) is a problem?

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Spivak
It’s not really a problem but it means that old cables that might be labeled
5G actually are the same as the new cables labeled 20G.

It just means that someone who is holding a USB-C cable can’t actually trust
the markings printed on the wire to know it’s capabilities — you have to plug
it into a computer to find out.

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irishsultan
You can trust it's label when it says it's capable of 5G (or at least you can
as much as you could before USB4). It's possible that it will perform better,
but unless you have a use case where it needs to be slow I'm not sure why this
erodes trust.

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Thomaschaaf
Why do they keep making the cables shorter? 0.8m seems very impractical for
applications like charging a phone.

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colejohnson66
Attenuation?

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eigenloss
no, dispersion.

