[scarface74]

Okay, still the same thought experiment. Pick up a random USB C cable. Now tell me:

How much power can it deliver?

Does it support data and at what speed?

Does it support video over USB C?

If I bought a cheap USB power only 5W cable and got the hypothetical iPhone 15 Pro Max with USB C support that could charge faster with a 20W cable, do 10Gps data transfer and video over USB C, wouldn’t I still end up throwing away the USB C cable I got with the $100 Android phone contributing to eWaste? Isn’t that the entire argument about forcing Apple to support USB C?

What happens when I buy a cheap USB C cord from the convenience store? Will it support “standard USB C”.

[tadfisher]

If that USB-C cable only supported 5W, then it does not meet the spec and must not carry USB-IF branding. At a minimum, USB-C cables must support 20V/3A and optionally support 20V/5A.

I get you on the rest of the issues, because the simplified USB-IF branding (Hi-Speed, SuperSpeed, SuperSpeed+, etc) crucially isn't printed on the cable itself. Moreover, the constant renumbering of the standard means manufacturers often forgo the consumer-facing branding and market devices/cables with the latest standard, which means nothing regarding what capabilities a device/cable supports.

USB-IF needs to be better at enforcement, for sure. In the meantime, I just just Thunderbolt cables for everything that needs advanced capabilities and pack-ins for everything else.

[scarface74]

How do you explain to the average consumer that even though all of these cords have USB C ends;

- the white cord that came with my old MacBook Pro 13 inch

- the little cable that came with my Beats Flex

- the cable that came with my Anker battery.

- any random overpriced USB C cable that you pick up from the convenience store or the bodega.

Are really USB C cables and that none of them support data?

[jsmith45]

Yeah this all is a mess, but if we restrict ourselves to considering only conformant cables then the problem is at least tractable.

All Type-C to Type-C support 60 W power delivery (3A at up to 20V), some support 100 W (5A at up to 20V) but those can no longer be certified, and the new 240W cables must have a certain logo on them that includes 240W clearly visible (and this means these cables can only be conformant if certified). And how much power a Type-C to Type-C cable can handle is completely orthogonal to the data it can transmit.

USB does allow conforming passive cables that only have USB 2.0 lines, which can support any of the voltages. These can often be differentiated from the cables that support USB 3.x/USB4 by way of the cable being surprising thin, but this becomes harder if it supports more than the minimum 60W.

Passive cables that support USB 3.x can vary in the maximum speed they support, which will also impact some alternate modes. If you want to ensure video support on a passive cable, your best option would be looking for a 0.8m or shorter passive cable that says 40Gbps, as those will all support the maximum currently allowed display-port bandwidth over type-c. [1] But all passive cables that include the USB 3.0 wires should support the lower Displayport 1.x alternative modes.

However, to reduce confusion in the future, USB-IF have recently revamped the rules for certified Type-C to Type-C cables. Cables must be marked with a logo that indicates 60W or 240W. If the cable supports 3.x or newer, it will also marked the max supported speed in Gbps as part of that logo. Failure to use the right logo for what your cable supports will result in failed certification.

Users are expected to assume that that any cable that does not specify wattage only supports 60W (since all USB C-to-C cables support that, except the optically isolated ones, which cannot be mistaken for a normal cable). Users are expected to assume passive cables do not support USB 3.0 data at all unless marked with: 1) a speed in Gbps, 2) a bare SuperSpeed logo (implies a max of 10 Gbps [2]) or 3) marked as Thunderbolt 3 (20 Gbps [3] unless a speed is otherwise shown).

Users are presumably expected to assume that active cables only support 5Gbps unless otherwise marked, and won't support any alternative modes (unless otherwise marked) if not marked as 40 Gbps, in which case DP2.0 alternate mode should work (but I'm not sure that display port 1.x modes are guaranteed to work).

Active cables are also where many problems lie especially as they don't always look different from passive cables. Active cables can mostly only support alternate modes that they were explicitly designed to support which for some is none at all. For example Active gen1 or Gen2 cables don't support USB4 at all. Active Thunderbolt 3 gen3 cables can be used for USB4 by some USB4 devices but this is an optional feature, so not all USB devices and hosts will support this.

Footnotes: [1] In theory, such cables should be able to handle DP 2.0 at UHBR 20 (80 Gbps) transfers, since they can reverse the 40Gbps return communication lanes, going from 40Gbps bidirectional to 80Gbps monodirectional. However VESA has not yet standardized that as an option. [2] Since these would probably be gen1 with 5Gbps per lane, and all typeC cables have two lanes in each direction. [3] Thunderbolt 3 implies gen 2, which as 10Gbps per lane, times two lanes in C-to-C cables.