5 ms·

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

by dmos62 1mo ago

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.

brookst 1mo ago
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.
- josephg 1mo ago
  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.
  - ProZsolt 1mo ago
    You mean something like this, which we have since 2021: https://learn.adafruit.com/understanding-usb-type-c-cable-types-pitfalls-and-more/overview https://learn.adafruit.com/understanding-usb-type-c-cable-ty...
    - josephg 1mo ago
      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.
- KronisLV 1mo ago
  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.
phil21 1mo ago
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.
- josephg 1mo ago
  > 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.
  - rtkwe 1mo ago
    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.
    - threecheese 1mo ago
      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…
selicos 1mo ago
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.

by dmos62 1mo ago

brookst 1mo ago

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.

josephg 1mo ago
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.
- ProZsolt 1mo ago
  You mean something like this, which we have since 2021: https://learn.adafruit.com/understanding-usb-type-c-cable-types-pitfalls-and-more/overview https://learn.adafruit.com/understanding-usb-type-c-cable-ty...
  - josephg 1mo ago
    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.
KronisLV 1mo ago
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.

phil21 1mo ago

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.

josephg 1mo ago
> 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.
- rtkwe 1mo ago
  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.
  - threecheese 1mo ago
    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…

selicos 1mo ago

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.