A nearly perfect USB cable tester

The thing that has been bothering me for a while is that the USB spec allows for software detection of capabilities. You can read the emarker data and see the supported protocols, speeds, voltages, etc.

But there is not standard for usb controllers to present this data to the OS. So it’s stuck in the low level firmware and never passed up. In theory we could have a popup box that tells you that both your computer and other device support higher speeds/more power, but your cable is limiting it.

Apple seems best able to do this since they control the hardware and OS, yet they aren’t doing it either. Users are just left to be confused about why things are slow.

I actually purchased one of these as this article has surfaced before.

It’s well worth the hype, I used it to audit all my cables (both for home and work) and it’s amazing how many thick and unwieldy cables are actually terrible for data.

For example I purchased a pair of B&W Px8 S2 noise cancelling headphones, which boast a DAC if you connect via USB-C directly, the cable it came with though was thick but only rated for USB 2.0 speeds. These headphones cost more than AirPods Max, which are themselves considered overpriced, and include comforts like nappa leather; so shipping with a chunky cable that doesn’t even carry decent data feels like a bizarre oversight. Apple’s own USB-C cables manage the same power delivery at less than half the thickness with a woven shell. You’d assume a premium product would at least match that.

Honourable mention to the USB-C cables that ship with Dell Ultrasharp monitors (both pre-USB4 and post). Those support basically everything except Thunderbolt 4 despite being unmarked.

I wasn't surprised to learn that when Linus Tech Tips released those new usb-c cables, that they all sold out almost instantly. They put their entire reputation on the line to claim (and label) the exact capabilities of their usb cables. Isn't that all we really want?

I want one that sends a pseudorandom data stream and tells me the bit error rate.

What I'm looking for is a differential signal tester, where you can breakout any arbitrary cable or traces and test the properties of the wire with different frequencies. It should be able to measure interesting properties such as resistance, capacitance, inductance, phase/length difference, wire length, etc.

One of these devices for approximately $100 would sell all day long.

This isn't a Beagle. When I first read the headline, I was hoping that it would be more than a smart continuity tester.

It seems to be a more comprehensive "Make sure the lines go where they are supposed to" tester. Looks pretty good.

But the devices that test things like transmission speed, are a lot more expensive.

I think that many of the issues that this device tests, can be mitigated by simply buying cables from reputable sources.

Man. I wonder if my cables are the reason why I cant get reliable transfer speeds above USB3.0 speeds on a new USB-C dock I purchased..

I didn't know there were cable testers like this, thank you.

Sucks that there's no USB-B support. Plenty of monitors still use it and many printers do as well

As someone who really doesn't care about learning the details, and just want one USB-C cable that does it ALL to put in my backpack what should I buy ?

One thing to realize is that especially for high resolution video cables these cheap testers can't really deliver. The way to test them is a eye diagram (see: https://incompliancemag.com/eye-diagram-part2/ ) and testers with that capsbility cost upwards of 10.000 Eurodollars.

Can you rewrite the emarker chips?

Brilliant little device. I will be picking one up ASAP!. Didn't know that lying cables were a thing but I have a ton of charge only cables?!

I speculate USB B wasn't included because there are only really two types, 2.0 (regular size) and 3.0 (has an obvious extension on the connector). There also don't tend to be power-only A-B cables because they are usually found on printers, Arduino s, ... And not for charging devices.

Fun fact: A Xiaomi fast charge cable (with orange plugs) has an extra contact on the A end to support USB C PD out of a USB A charger.

Similarly: Is there a USB-C power delivery adapter to force directionality? I needed to siphon off power from small batteries into a larger pack (that could supply more power out than the small packs) in a power outage. I absolutely could not force my larger power station to accept a charge and it kept pushing power back the wrong direction despite which ends of the cable I plugged in first.

I just want one that tells me the maximum voltage and current supported by a USB C cable.

I’ve had one for a while as well. I don’t use it often, but frankly I couldn’t sort my cables without it.

Hopefully they used connectors with a high mating cycle rating.

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