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Okay, great, it’s called USB-D. Is this a new connector? Or do we now need to resort to labeling cables and checking the label?

Do we do this for every new version and combination of versions for USB? USB-PD? Thunderbolt? DisplayPort?



Ehem, we already do that. USB-C is an umbrella term and everyone has a homebaked organizing system to tell which USB-C cable can do what, or a homebaked testing routine where we run through 5 cables each time we need to connect something.

That's what the article is about. Calling all these cables USB-C and making them look indistinguishable is a very leaky abstraction.


So there are 4 different current-carrying levels, from 2.5A to 5A EPR.

There are 6 different transfer speeds, from 480mbps to 120gbps.

There’s DisplayPort yes/no.

There are 4 thunderbolt genrations, each with its own marker.

Some of those are dependent (480mbps cables don’t have markers), so it’s not a full permutation problem. Only about 20 different combinations are valid.

Is the proposal to have 20 different physical connectors? Or to prune the space down to 6 or so by requiring all cables to be very thick, or to support higher transfer speeds than make any sense for a charging cable?

It’s not a leaky abstraction. It’s a physical interface standard that does not guarantee electrical properties. Same way you can plug a 6A cord and a 20A cord into the same electrical outlet.


That can be solved the same way it was solved for SD / CFe cards. Just have a single mark which guarantees a baseline set of requirements.

- "USB Speed 2" means [20gbps, thunderbolt 3, displayport, 20 watts].

- "USB Speed 3" means 100gbps, thunderbolt 4, etc.

- "Power 100" means 100 watts minimum.

Make a little logo for each standard - "S2" / "S3" / "P100" which can be branded onto each end of the cable. People who care can look at the logos and tell what a given cable can do.


You mean something like this, which we have since 2021: https://learn.adafruit.com/understanding-usb-type-c-cable-ty...


Yes, like that but something that actually gets used. And it'd be good to have a way to know how much power a cable supports too.

Thanks for the link. I didn't know those labels also tell you if a cable supports displayport alt mode and thunderbolt 3.


USB3-5A-10Gbps-DP-TB3-C would be pretty gnarly as a label even if it’d still be a Type C at the end of the day.


They are all USB C form factor port cables. The actual functionality being different is a USB spec/labelling failure not one of naming.

Thunderbolt is also a USB C form factor/port, just has better naming and private control over usage.

I have a similar USB tester as the author. It's rather useful and inexpensive. Good bit of homelab kit.


I mean, if you care about this and it annoys you the fix is very simple and relatively cheap.

Just set a minimum baseline/standardization for the type of cable/capabilities you need for your highest end device. Only keep those cables, give away the rest, and buy a half dozen new cables so no matter which you select you will always get the right one.

I've rarely found I need a "special" USB-C cable outside of connecting Thunderbolt ports. Those are mostly static on my monitors, with one in my laptop bag. They also happen to be decently labeled on the connector with what they are.

Once in a while I get an incredibly cheap horrible one from some throw away style device and I simply toss the cable immediately.

The only exception I can think of are USB-A -> USB-C adapter cables where the device is so cheap it doesn't implement USB-C PD delivery at all and expects a "dumb" 5V connection. That is a charger issue though, not a cabling one. Those devices are luckily starting to become much more rare.

I purged the house of the worst 5W USB-A charges long ago in a fit of rage. Anything that couldn't do 15W was tossed. We still have more 15W chargers than I could ever use in a lifetime.


> Just set a minimum baseline/standardization for the type of cable/capabilities you need for your highest end device. Only keep those cables, give away the rest

I don't have a cable tester, and I don't want to buy one. The companies who make USB cables should be responsible for this testing. I don't want to do expensive homework on behalf of USB cable companies.


Buy nice cables from a trusted brand and bin anything else. You're going to be overpaying though because there's not a lot of reason to be powering your laptop with a 480 Gbps TB 4 USB-C cable.


That’s not all you need to do though; once you have bought all Cable Matters or Anker cables, you still need to remember which one charges your iPhone quickly, and which one is thunderbolt-capable but missing the lightning bolt, which one is charging-only, etc. I have a whole mess of cables - and several of these dongles (you need a usb-a capable one, and only that other one reads thunderbolt markers, etc). I spend the time to label any cable that I buy myself, and wish the vendors would do it instead.

From reading TT, it seems there’s just no easy solution to complexity if we want interoperability.

I didn’t hate lightning cables…


I've done this and the answer is they all charge my phone quickly and I know the handful that are the highspeed cables either by the markings or knowing which of them are the good cables.


The computer / phone should auto-detect and tell you on-screen


They've already done that afaik, like warning about charging at slower speed.


Some chargers will re-negotiate depending how many cables are plugged into the adapter. Which is fine, but sometimes makes it tricky to know if it's the cable, the plug, or the number of cables causing a slow charge


Haven’t ever seen a warning like that in KDE.


The hell Apple or Google cares.


Apple should care because customers will blame slow charging times and slow transfer speeds on the phone


I think Apple much rather tells users that this is exactly what they warned them about when they were forced to support USB-C and will advise users to only buy official cables from Apple.


You mean USB-C, the standard that they largely led development of?


No, they mean USB-C, the port they switched all but a handful of their devices to before any other manufacturer.

While GP’s take is ridiculous (if common), I do think the notion that Apple led the charge on USB-C is mostly a myth, outside of them being active participants on the USB Implementor’s Forum.


Eh, I can’t find it now so a thousand grains of salt, but I read a good article back in the day about how much Apple’s experience with in-market Lightning shaped USB-C’s physical connector and electrical handshake.


> Do we do this for every new version and combination of versions for USB? USB-PD? Thunderbolt? DisplayPort?

Yes.


I don’t think you fully comprehend the matrix of legal possibilities for a cable with USB-C connectors.


Yes, a new connector would be great. It could be a notch on the standard usb-c form factor, so that usb-c connectors could fit into usb-d plugs.


> Or do we now need to resort to labeling cables and checking the label?

YES oh please yes! Give me labels! I'm sick of playing guessing games with my USB cables. Which one should I use for my external drive? This cable is thick! Will it work? Maybe it's only thick so it can send power? It seems impossible to tell, even if I plug it in to my computer. The files are there, I just need to somehow guess that it's a bit slower than it's supposed to go. Another cable feels expensive but its 1m. Will it work? Do I get slower data rates? I can't tell. I hate guessing. Label the cables!


Color coding seems good




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