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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?

#61

Post by sambroner »

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…

Can you link to some cables that are certified to implement the entire standard? Even that has been difficult for me to find.

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

#62

Post by llampx »

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.

Also the most expensive option and limited in terms of maximum length.

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

#63

Post by llampx »

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?

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

#64

Post by djsumdog »

mrb wrote: post #55
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…

« But is a 5Gbps cable enough? Or is a 10Gbps cable needed? » Here is the answer: if you need DisplayPort 1.0-1.2, a 5 Gbps cable is enough. If you need DP 1.3-1.4 (where they upped the transfer rate for higher resolution and fps,) you need a 10 Gbps cable. If you need DP 2.0 (I don't think products are out yet, the standard was finalized last month,) you will need a USB4 20 Gbps cable.

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

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

#65

Post by Dylan16807 »

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…

There are plenty of cables that are cheap and support everything that's actually in a USB standard. They only go up to 1 meter, though. Even thunderbolt 3 isn't too expensive over short cables. They don't need to be expensive.

At the other end of the spectrum, there don't seem to be any cables that support both thunderbolt 3 and USB 3 at 2 meters, no matter how much you're willing to spend.

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

#66

Post by djsumdog »

llampx wrote: post #62
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.

Also the most expensive option and limited in terms of maximum length.

How are the Thunderbolt cables wired? Do they have more than the 10 USB3 wires or is it just a higher standard of cable?

Isn't USB4 = the next Thunderbolt standard?

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

#67

Post by bArray »

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 mystery might not even be completely solved then, have you confirmed that it's not performing some unwanted compression to get your data over a lower-bandwidth cable?

Maybe a good indication would be to check your CPU usage before and after using 5Gb/s and 10Gb/s cables. Even then it's not a great indication, many modern processors have dedicated modules on the CPU for video compression/decompression (given how large the use case is, it makes sense).

And then you have other factors that may prevent you getting full speed:

* Connection between the cable and the device on both sides (oxidization, scratches, etc)

* Manufacturing flaws or damage during delivery/use in the cable (un-shielded areas, breakages in the cable, imperfections in metals, etc)

* Temperature - if you're pulling 20W through this cable it's not entirely impossible you might start noticing some heat, especially if it wasn't designed to take the power draw (increased heat due to power pull = greater resistance = worse signal)

My pointy is, as we turn up the requirements of these cables, just making sure they deliver on their promises will become more difficult. Most people won't have an oscilloscope that can even measure these cables anymore and just the act of putting the oscilloscope on the lines increases capacitance and changes how the signal looks.

A while back I had issues with two Ethernet cables (CAT 7 I think), both straight out of the packet, one performed at half speed and the other at full. I was tearing my hair out for a while before I realized why the network was bottle necked.

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

#68

Post by ben-schaaf »

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…

> 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.

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

#69

Post by msbarnett »

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…

> 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 Switch, which it “obviously” “must” support because it’s USB-C and eGPUs have “supported” USB-C for years.

And now, Nintendo has announced a Switch Lite with no TV out (presumably they removed the DisplayPort crossbar IC that does alternate mode muxing with the USB 3.0 signal, to reduce manufacturing costs). But Joe Average Consumer is up in arms, this “must be them sabotaging it in software”, because “video out is a required part of the USB-C standard, this wouldn’t even save them any money, USB-C always physically supports video out”.

The average consumer in no way understands that USB-C is just a connector shape that a bunch of different incompatible things use. They think that, like almost all previous ports, the shape indicates a common protocol that is shared by things that have that shape. And they are absolutely complaining about a lack of what they perceive should be compatibility.

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

#70

Post by manacit »

Ductapemaster wrote: post #36
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…

Out of curiosity, what USB-C dock do you have? I am in the market for one.

I (and a number of people I know) have a CalDigit TS3+ and it's worked extremely well for me: https://www.caldigit.com/ts3-plus

I can't speak to what else is on the market, but there's not more I'd want from this.

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