- will it charge my MacBook Pro 16” and deliver the full 100W?
- will it supply data and if so, at what speed?
- can it deliver power and video over USB C and work with my portable secondary display?
(Note: If you change “USB C” cable to “Thunderbolt 3” cable, those choices are all zeroed out. So the answer to that modified question is “yes”, since 100W support is mandatory in Thunderbolt 3 cables.)
This will get better over the next year for certified cables that print USB-compliant logos on them, with the end of SuperSpeed branding:
https://news.ycombinator.com/item?id=33034530
> Branding for certified USB Type-C cables is also being updated. Rather than simply listing their data transfer speeds, cables will also (for the most part) have to list the charging wattage they’re capable of carrying. So a cable can’t just be branded as being a 40Gbps cable as with last year’s guidelines, it’ll now also have to list a charging speed like 60W or 240W.
But I’ve never seen the USB logos printed on a cable before, so it remains to be seen whether the reduction in complexity to Gbps/W only is sufficient to persuade cable makers to certify their cables or not.
this is a major problem they need to figure out imo.
edit: or move to a new major version (usb 4.0) and make all new cables do all of that so if you get a 4.0 cable, you know you can use it for everything at once. i have no idea if this is currently the plan or not.
They're already at USB4 version 2.0
If it's e-marked, then yes.
> - will it supply data and if so, at what speed? > - can it deliver power and video over USB C and work with my portable secondary display?
If it's not just a USB 2.0 cable, then yes.
- the USB C cable that came with the x86 Macs and most USB C charging cables are power only and don’t support data
- many USB C cables that do support data only support data at USB2 speeds and don’t support video over USB
- I think some cables can support video over USB C. But only support data at lower speeds than 10Gbps.
https://www.macintoshhowto.com/hardware/why-your-usb-c-cable...
Really, unless you need to get the highest bandwidth available from latest USB standards, it's not that complicated at all. In most non-Thunderbolt cases, all you need to know is whether your cable is USB 2.0 only or not - and Thunderbolt cables tend to be obviously marked as such.