Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

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

people.kernel.org

Post reply on HN
Print view View original

111–120 of 210 posts

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

#111

Post by jrockway »

shrimp_emoji wrote: post #19
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".

That or it's a spectacular example of committee design failure. I can't tell what runs deeper: evil or stupidity. :D

I don't think it's malice or stupidity, but rather a desire to fix people's problems and get it right this time. xkcd sums it up best: https://xkcd.com/927/

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

#112

Post by DoofusOfDeath »

wmf wrote: post #95
Simulacra wrote: post #86

It has become beyond ridiculous. We need to standardized around one cable. I get it, we can't have government doing this, but I'm at a complete loss for who else could? IEEE?

USB-IF already has certification but they aren't willing to kill off non-certified cables (which are 99% of the market).

I wonder if this puts them at risk of losing the "USB" trademark because they're not actively defending it.

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

#113

Post by AceJohnny2 »

Dylan16807 wrote: post #71
AceJohnny2 wrote: post #58

Earlier quoted context omitted.

> 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.

Per the Thunderbolt FAQ [1]

> What is Thunderbolt 3?

> Computer ports with Thunderbolt 3 provide 40Gbps Thunderbolt – double the speed of the previous generation, USB 3.1 10Gbps, and DisplayPort 1.2.

I'm curious: which active cable did you use that didn't support DP?

[1] https://thunderbolttechnology.net/tech/faq

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

#115

Post by basicplus2 »

In my oinion all USB-C cables should be identical and negotiation for power etc should be done inside the connected equipment, not inside a cable connecting the two pieces of equipment.

However it is an excellent opportunity to cheaply embed spyware chips inside USB cables with markings that cannot be distinguished from the genuine Electronic Marker chips.

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

#116

Post by Dylan16807 »

AceJohnny2 wrote: post #113
Dylan16807 wrote: post #71

Earlier quoted context omitted.

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

Per the Thunderbolt FAQ [1] > What is Thunderbolt 3? > Computer ports with Thunderbolt 3 provide 40Gbps Thunderbolt – double the speed of the previous generation, USB 3.1 10Gbps, and DisplayPort 1.2 . I'm curious: which active cable did you use that didn't support DP? [1] https://thunderbolttechnology.net/tech/faq

Note: This cable does not support native DisplayPort 1.2 or Thunderbolt 3 connections to a DisplayPort monitor. https://amazon.com/StarTech-com-Thunderbolt-Cable-40Gbps-Cha...

Regular USB-C monitor is not support, USB 3.1/3.0/2.0 and USB-C is not support https://amazon.com/Thunderbolt-Certified-Nekteck-Compatible-...

USB 2.0 ️[check], USB 3.0 [ ], DisplayPort [ ] https://amazon.com/Belkin-Thunderbolt-Cable-Feet-Meters/dp/B...

Can you point me to any 2-meter thunderbolt@40GHz cable that does support USB 3 and/or DisplayPort? None of the ones in this chart can do it: https://docs.google.com/spreadsheets/d/1vnpEXfo2HCGADdd9G2x9... Only the 1-meter active cable can.

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

#117

Post by ploxiln »

deepsun wrote: post #110
Godel_unicode wrote: post #91

Earlier quoted context omitted.

They did, kind of. USB2, USB3.1 gen 1, and USB 3.1 gen 2 are 480mbps, 5gbps/DP-alt-mode and 10gbps/DP-alt-mode, respectively. The problem is really that people won't remember that distinction unless they need to know it regularly, and unless you know to Google "difference between USB 3.1 gen 1 gen 2" you won't be able to figure it out.

Would be easier to rename "USB 3.1 gen 2" -> "USB 3.2". And the latter two would be "USB 3.3", "USB 3.4", problem solved :)

They really only ever make it worse.

Initially, there was USB 3.0 at 5Gbps, USB 2.0 at 480Mbps, and USB 1.1 at 12 Mbps.

Then, when they added a 10Gbps mode, they called it USB 3.1 Gen 2, and renamed USB 3.0 to USB 3.1 Gen 1.

They already have plans for USB 3.2: 5Gbps will be USB 3.2 Gen 1, 10Gbps will be USB 3.2 Gen 2, and 20 Gbps will be USB 3.2 Gen 2x2. Yup, Gen 2x2 is next.

And there is no more USB 3.0 - presumably no vendor wants to have to sell an older number, so they rename them all so consumers are confused and think they are all the latest 3.x

ref: https://arstechnica.com/gadgets/2019/02/usb-3-2-is-going-to-...

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

#118

Post by reaperducer »

ploxiln wrote: post #117
deepsun wrote: post #110

Earlier quoted context omitted.

Would be easier to rename "USB 3.1 gen 2" -> "USB 3.2". And the latter two would be "USB 3.3", "USB 3.4", problem solved :)

They really only ever make it worse. Initially, there was USB 3.0 at 5Gbps, USB 2.0 at 480Mbps, and USB 1.1 at 12 Mbps. Then, when they added a 10Gbps mode, they called it USB 3.1 Gen 2, and renamed USB 3.0 to USB 3.1 Gen 1. They already have plans for USB 3.2: 5Gbps will be USB 3.2 Gen 1, 10Gbps will be USB 3.2 Gen 2, and 20 Gbps will be USB 3.2 Gen 2x2. Yup, Gen 2x2 is next. And there is no more USB 3.0 - presumabl…

At this point, I don't blame Apple for holding on to Lightning.

As soon as its phones go USB-C, they're going to have to deal with half a million people on the internet complaining that their junk shop cable doesn't work right or do what they thought it would.

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

#120

Post by mrb »

kllrnohj wrote: post #103
djsumdog wrote: post #64

Earlier quoted context omitted.

DP1.2a should be enough for 60Hz at UHD/2160p. 1.4 is needed for HDR support, 5K, higher refresh rates, etc.

DP 1.2a goes up to 21.60 Gbit/s, and 4k 60hz (which does work fine over 1.2a) needs 12.54 Gbit/s. I'm not sure how the 5Gbit/s and 10Gbit/s USB-C cables fit into this. It's obviously not just based on the cable's "rated" bandwidth, as if it was neither the 5Gbit/s nor 10Gbit/s connection would work at all for display. But it does, so it must not be, so what is it? Is it 5Gbit/s per twisted pair? That would make sense…

«I'm not sure how the 5Gbit/s and 10Gbit/s USB-C cables fit into this.»

A USB3 cable has 4 differential pairs. When in alt mode, all 4 pairs transmit in the same direction, so a 5 Gbit/s cable can transmit 20 Gbit/s.

Post reply on HN