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I stopped trusting USB-C cable labels and started testing them

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Re: I stopped trusting USB-C cable labels and started testing them

#71
I came up with a color code based on the wiring: Red for Power Only, Blue for USB 2.0, Green for USB 3 (the ones with the extra pairs connected). I use paint pens to mark every cable I come across with this code. Generally speaking, only the Green ones have special PD emarker chips.

It doesn't cover every possible configuration, but it's good enough for when I'm like "I need a USB cable" vs "I need a good USB cable"

I use this tester: https://www.amazon.com/dp/B0CF95VL2Y

Re: I stopped trusting USB-C cable labels and started testing them

#72

> But I shouldn't have had to do any of this. It's time cables came with a label of their own, or some sort of color coding. There shouldn't even need to be a label. A USB-C cable should be a USB-C cable should be a USB-C cable. There should be a single connectivity/performance spec, and if the cable meets it, it can be called a USB-C cable, and if it doesn't, it should have to be marketed as USB-JUNK or something. T…

Unless you want all cables to be thick, $60, and cap out at 1 meter long, this is not a reasonable standard. 480mbps USB-C is perfectly adequate for many applications. Likewise for 60W cables.

Re: I stopped trusting USB-C cable labels and started testing them

#73
post #72

> But I shouldn't have had to do any of this. It's time cables came with a label of their own, or some sort of color coding. There shouldn't even need to be a label. A USB-C cable should be a USB-C cable should be a USB-C cable. There should be a single connectivity/performance spec, and if the cable meets it, it can be called a USB-C cable, and if it doesn't, it should have to be marketed as USB-JUNK or something. T…

Unless you want all cables to be thick, $60, and cap out at 1 meter long, this is not a reasonable standard. 480mbps USB-C is perfectly adequate for many applications. Likewise for 60W cables.

So, call it USB-D or something, if one cable is significantly different (in purpose, performance, form factor) than another cable. Don't just call everything the same label, and let the non-technical buyer beware.

Re: I stopped trusting USB-C cable labels and started testing them

#74
post #36

Earlier quoted context omitted.

This effectively only tells you what the E-Marker reports though, the actual capabilities of the cable are still unknown. You can say the cable can do whatever you want on the E-Marker, its not the source of truth. The problem is, to actually benchmark everything, voltage drop, resistance, actual bandwidth (especially at Thunderbolt 5 speeds) requires a lot of hardware. Using a USB-C Test Controller ($13,000), connec…

well, that's disappointing; someone needs to miniaturize that and reduce the cost massively

It’ll never happen. Measuring to the proper Thunderbolt spec is only possible on literally the most cutting edge measurement equipment. Physics just won’t permit that being a gadget you can buy for $20 of whatever.

Re: I stopped trusting USB-C cable labels and started testing them

#75

As always, these testers (the affordable ones) are capable of testing continuity, and, I guess, the cable chip report. If you want to test bandwidth, that's a five- or six-figure bit of gear.

Why on earth is so much more expensive than an arbitrary pair of devices that could max out a cable?

Re: I stopped trusting USB-C cable labels and started testing them

#76
> Any cable that can transfer data faster than USB 2.0 speeds also requires a chip to do so.

I always found this confusing because USB 3.0 Micro-B cables can transfer data faster than USB 2.0 without needing an e-marker, so why do USB-C cables need one if they already have the Tx and Rx SuperSpeed wires?

It seems like the answer is, roughly, "it's complicated".

https://old.reddit.com/r/UsbCHardware/comments/1ow1tpf/why_d...

https://old.reddit.com/r/UsbCHardware/comments/13j0gev/do_us...

Re: I stopped trusting USB-C cable labels and started testing them

#77
That's an ad. There's a lot of cable testers around, most of them are crap. Cheap testers like this one are based on generic chips reading e-markers and aren't even guaranteed to support all quick charging standards. And bandwidth is another matter entirely.

Re: I stopped trusting USB-C cable labels and started testing them

#78
post #72

Earlier quoted context omitted.

Unless you want all cables to be thick, $60, and cap out at 1 meter long, this is not a reasonable standard. 480mbps USB-C is perfectly adequate for many applications. Likewise for 60W cables.

So, call it USB-D or something, if one cable is significantly different (in purpose, performance, form factor) than another cable. Don't just call everything the same label, and let the non-technical buyer beware.

The naming could be better for sure.

Re: I stopped trusting USB-C cable labels and started testing them

#79

> But I shouldn't have had to do any of this. It's time cables came with a label of their own, or some sort of color coding. There shouldn't even need to be a label. A USB-C cable should be a USB-C cable should be a USB-C cable. There should be a single connectivity/performance spec, and if the cable meets it, it can be called a USB-C cable, and if it doesn't, it should have to be marketed as USB-JUNK or something. T…

I think you didn't put a lot of research in before making this recommendation. Labels make more sense because the top tier USB c specs are darn expensive.....

Re: I stopped trusting USB-C cable labels and started testing them

#80

As always, these testers (the affordable ones) are capable of testing continuity, and, I guess, the cable chip report. If you want to test bandwidth, that's a five- or six-figure bit of gear.

Why on earth is so much more expensive than an arbitrary pair of devices that could max out a cable?

Think about it.

You need to generate a precise, calibrated, 40GHz signal, transmit it, then precisely measure the returned signal for phase, amplitude, and waveform integrity -at that speed.

Oscilloscopes and logic analyzers that run at that speed, are damn expensive.

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