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How many kinds of USB-C to USB-C cables are there?

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Re: How many kinds of USB-C to USB-C cables are there?

#71

Post by Dylan16807 »

AceJohnny2 wrote: post #58
starsinspace wrote: post #42

After buying a screen which has only a USB-C DP-Alt-Mode input, I was recently in the market for a matching cable. My only requirements were “it should be as long as possible, at least 2 meters” and “it needs to support DP-Alt-Mode”. Now I thought this would be easy, just ask Google what kind of cable I need, right...? Well... no. Not at all. I wasn’t able to find any information whatsoever what kind of USB-C cable i…

> It needs to support DP-Alt-Mode For future reference, a Thunderbolt 3 cable (which is USB-C connector) will work.

Not true! Active thunderbolt 3 cables often only support thunderbolt 3.

Re: How many kinds of USB-C to USB-C cables are there?

#72

Post by manacit »

llampx wrote: post #63
manacit wrote: post #13

I've had a USB-C capable device (MBP) for a few years now, and it originally was extremely annoying. Needing dongles for _everything_ was annoying, and getting rid of Magsafe meant a lot of my existing chargers that I'd accumulated no longer worked. My work laptop (at the time) didn't use USB-C, so I had to keep two chargers around, and I couldn't charge my iPhone from my laptop at all. Fast forward a few years and I…

Paying for extra stuff and more expensive cables, for what benefit again? I could throw out all my USB peripherals and buy new ones that use USB type C, but at the end what have I achieved aside from setting a few $100 bills on fire?

For me, it's the difference between having to plug in at least 5 things when I set my laptop down at my desk (or use a very specific dock that only works with a single size and model of laptop) to just plugging USB C in and having my laptop charge and function with every device. This is worth the price of admission, though the decision was made for me by Apple.

Beyond that, the additional wattage that USB C PD provides means that I can charge my iPhone and iPad significantly faster than even with Apple's "fast" 12W charger previously. This is really nice when I am traveling or just forgot to charge my iPhone.

In addition, now that more devices are coming with USB C support, I can charge everything from my laptop to my Bose headphones with the same cable and charger, which would have not been possible before.

Re: How many kinds of USB-C to USB-C cables are there?

#73

Post by zarathustraa »

derefr wrote: post #57
starsinspace wrote: post #42

After buying a screen which has only a USB-C DP-Alt-Mode input, I was recently in the market for a matching cable. My only requirements were “it should be as long as possible, at least 2 meters” and “it needs to support DP-Alt-Mode”. Now I thought this would be easy, just ask Google what kind of cable I need, right...? Well... no. Not at all. I wasn’t able to find any information whatsoever what kind of USB-C cable i…

The answer is supposed to be easy; it's "you need to buy one of those really expensive USB-C Thunderbolt 3 cables, because those cables—the ones that do everything—are supposed to be the only type of USB-C cables." USB-C cables are supposed to be universal, i.e. have all the features, all the time; and thus, USB-C cables should (in 2019) be very expensive. Any USB-C cable that isn't very expensive (in 2019) isn't fol…

My Samsung phone came with a very thin USB-C cable that only supports USB 2.0 speeds. I think that's following the standard.

Re: How many kinds of USB-C to USB-C cables are there?

#74

Post by wongarsu »

derefr wrote: post #60
Causality1 wrote: post #32

Earlier quoted context omitted.

It's a bloody goddamned nightmare. For example, a brief review of my devices: >Phone A. Type-C port limited to USB 2 data speeds but supports HDMI out via DisplayLink. >Phone B. Type-C port that supports USB 3.1 speeds but doesn't do video out. >Tablet A. Type-C port that supports USB 3 speeds but only charges through a MicroUSB port. >Tablet B. Type-C port that supports USB 3 speeds and charging, but only charges at…

I don't see your point. Devices are free to support or not support whatever capabilities they want. Having a specific port is no guarantee that the device will use this or that capability offered over that port; mostly it's a guarantee it'll use at least one capability offered by that port. The problem with USB-C is that many of the cables don't do everything. Nobody else is complaining that the devices don't do ever…

If a device has an HDMI port I know I can use that to connect a display. I don't know details like the supported resolutions, but at least I know that's a supported use case.

If I notice that a device has a USB-C port all I really learned is that it has a USB-C port. Who knows what it does.

Re: How many kinds of USB-C to USB-C cables are there?

#75

Post by bobthepanda »

crispyambulance wrote: post #10

So frustrating. One would think that after nearly 2 decades of consumer confusion over USB cables that it would be possible to just mark the cables in a clear way with a non-confusing, easily looked up logo (or better, with a alphanumeric-code). It makes me wonder if manufacturers are just doing this to increase the churn of cable sales, so consumers end up buying more cables because "some work and some don't".

Even better, why not just make incompatible cables impossible to intermix by, say, using different ports?

Re: How many kinds of USB-C to USB-C cables are there?

#76

Post by derefr »

ben-schaaf wrote: post #68
derefr wrote: post #57

Earlier quoted context omitted.

The answer is supposed to be easy; it's "you need to buy one of those really expensive USB-C Thunderbolt 3 cables, because those cables—the ones that do everything—are supposed to be the only type of USB-C cables." USB-C cables are supposed to be universal, i.e. have all the features, all the time; and thus, USB-C cables should (in 2019) be very expensive. Any USB-C cable that isn't very expensive (in 2019) isn't fol…

> USB-C cables are supposed to be universal I may be wrong here, but from what I understand this doesn't seem to be the case (DP, Thunderbolt, etc. are all "optional"). It would also mean that all cables would be limited to 50cm.

There was the design intent, and then there was the final standard.

The USB-IF is composed of manufacturers that wanted to be able to cheap out on cables; so of course they made all the expensive features optional, at the expense of anything USB-C was designed to accomplish.

In an alternate world where USB-IF was headed by a benevolent-dictator-for-life, USB-C wouldn't have any optional features. (It'd also be in nearly nothing, because no manufacturer would want to pay the BOM costs of supporting it.)

Re: How many kinds of USB-C to USB-C cables are there?

#78

Post by Dylan16807 »

msbarnett wrote: post #69
derefr wrote: post #60

Earlier quoted context omitted.

I don't see your point. Devices are free to support or not support whatever capabilities they want. Having a specific port is no guarantee that the device will use this or that capability offered over that port; mostly it's a guarantee it'll use at least one capability offered by that port. The problem with USB-C is that many of the cables don't do everything. Nobody else is complaining that the devices don't do ever…

> Nobody else is complaining that the devices don't do everything. Tons of regular consumers think that USB-C is a protocol and frequently complain that things they think should work together don’t, because they’re actually radically different ports electrically that happen to be shaped the same. Gaming forums are rife with elaborate conspiracy theories behind why Nintendo won’t “just” release an eGPU Dock for the Sw…

> presumably the removed the DisplayPort crossbar IC that does alternate mode muxing with the USB 3.0 signal, to reduce manufacturing costs

It probably saves some amount of money, but I'd bet that deliberately leaving it out to encourage sales of the full switch is a bigger factor.

Otherwise I agree with you about protocol confusion.

(Would you even need a mux? I don't think the switch uses USB 3 for anything.)

Re: How many kinds of USB-C to USB-C cables are there?

#79

Post by jrochkind1 »

starsinspace wrote: post #42

After buying a screen which has only a USB-C DP-Alt-Mode input, I was recently in the market for a matching cable. My only requirements were “it should be as long as possible, at least 2 meters” and “it needs to support DP-Alt-Mode”. Now I thought this would be easy, just ask Google what kind of cable I need, right...? Well... no. Not at all. I wasn’t able to find any information whatsoever what kind of USB-C cable i…

Why don't they give NAMES to these different types of cables?

They seem to have either no names or too many names where it's unclear what is intended for the consumer.

Just giving the cable a clear name (in words, not icons), so you could know what you were buying, and a device could say "you need this kind of cable", and a person could write a blog saying "to support DP-Alt-Mode you need X kind of cable" and all use the terminology... would seem to go a long way.

It seems odd that the USB people have not figured this out.

We can't even figure out what the CALL em all consistently.

Re: How many kinds of USB-C to USB-C cables are there?

#80

Post by derefr »

wongarsu wrote: post #74
derefr wrote: post #60

Earlier quoted context omitted.

I don't see your point. Devices are free to support or not support whatever capabilities they want. Having a specific port is no guarantee that the device will use this or that capability offered over that port; mostly it's a guarantee it'll use at least one capability offered by that port. The problem with USB-C is that many of the cables don't do everything. Nobody else is complaining that the devices don't do ever…

If a device has an HDMI port I know I can use that to connect a display. I don't know details like the supported resolutions, but at least I know that's a supported use case. If I notice that a device has a USB-C port all I really learned is that it has a USB-C port. Who knows what it does.

But that's most port standards that have ever existed.

What can a device do with a parallel port? A serial port? A SCSI port? A Firewire port? Who knows? It's up to the device. It can certainly send signals over that port, of some kind. But what kind of signals? Up to the device. The host can hopefully probe a device-class out of the client and stand up an appropriate driver to talk to it.

A CD player has a 3.5mm audio jack. Pop quiz: does it support SPDIF? In fact, is it line-level or phono-level output? (An important question to avoid blowing out your equipment!) Answer, in both cases: who knows?

You find a random CAT-6 drop in the wall. Does it contain Ethernet? Does it contain Power-over-Ethernet? Does it contain both? No way to know without asking someone or plugging it in.

Or, for a slightly more interesting example of a "port": what can a random peripheral board do with a motherboard's PCI-e (or PCI, or ISA, or any historical equivalent) port? Well, whatever it likes. Does anyone expect every PCI card to be simultaneously a network card, graphics card, sound card, RAID card, etc., just because those are all things PCI can carry? Of course not. PCI-e is a single port, and a single protocol (sort of), but that doesn't mean it's a single set of exposed capabilities.

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