3 ms·

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

by brookst 2mo 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 2mo 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 2mo 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 2mo 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 2mo 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.

by brookst 2mo ago

josephg 2mo 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 2mo 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 2mo 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 2mo 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.