Technology: The (nearly) perfect USB cable tester does exist

(blog.literarily-starved.com)

82 points | by birdculture 3 days ago

8 comments

  • ChrisMarshallNY 4 minutes ago
    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.

  • Gigachad 3 hours ago
    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.

    • QuantumNomad_ 18 minutes ago
      On iPhone, when connecting an external MIDI device via USB, the phone told me that the device was drawing too much power and would be disabled.

      I don’t know if they check that via USB protocol, or if they are measuring the actual power draw on the USB port.

      In order to use the device, I had to connect it via an externally powered USB hub.

    • avian 2 hours ago
      > 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.

      I'm pretty sure my old Dell XPS laptop with Windows 10 had pop-ups just like this.

      "This device can run faster" or something.

      • Vogtinator 1 hour ago
        AFAIK that's just when plugging in a USB 3 device into a USB 2 port or using a USB 2 cable.
      • LoganDark 2 hours ago
        Even Apple now has one of those, when you plug something into the USB 2 port on the MacBook Neo.
    • graemep 1 hour ago
      I suspect most users do not even realise things are slow.
      • TeMPOraL 33 minutes ago
        Oh, they very much do. But like with everything in technology, they can do fuck all about it, so they resign and maybe complain to you occasionally if you're the designated (in)voluntary tech support person for your family and friends.

        Regular people hate technology, both for how magical and how badly broken it is, but they've long learned they're powerless to change it - nobody listens to their complaints, and the whole market is supply-driven, i.e. you get to choose from what vendors graciously put on the market, not from what the space of possible devices.

  • seanalltogether 1 hour ago
    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?
  • amelius 2 hours ago
    I want one that sends a pseudorandom data stream and tells me the bit error rate.
  • atoav 2 hours ago
    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.
    • jmalicki 1 hour ago
      So you're saying there is something to audiophile grade HDMI cables?
      • scq 1 hour ago
        No. What it can affect though is the bandwidth of the cable, meaning e.g. for HDMI cables, they might not support higher resolutions or framerates. If it's on the border you might see random disconnects or screen blanks.

        The quality degrading is not something you will see, as it's a digital protocol.

        "Audiophile grade" HDMI cables are likely to just be a Shenzhen bargain-bin special with some fancy looking sheathing and connectors. I would trust them less than an Amazon Basics cable.

        • fmajid 1 hour ago
          Indeed. If I want super high quality cables, I get them from Blue Jeans Cables, who tell you exactly what Belsen or Can are cable stock and what connectors, as well as the assembly methodology.
      • HPsquared 1 hour ago
        With digital signals and ECC, the cable need only be "good enough" to get perfect data transfer through the system.
        • jmalicki 53 minutes ago
          His link made very clear the issues of jitter and flickering.
      • atoav 1 hour ago
        No. What I am saying is that it is hard to test the quality of a 8K 240Hz 4444 video cable without having a device that can send and receive this or even higher.

        If you send bits across a line fast enough you're grtting into the territory of RF electronics, with wrong connector or conductor geometry you will get echos on the line and all kind of signal loss. A good digital protocol should keep this at bay with error correction and similar mechanisms, but if you want to know what the good cable is on a better than binary scale of works/does not, you need to look at these things.

        • jmalicki 51 minutes ago
          I just need to make a cable with better eye diagrams so I can market it to AV enthusiasts with "golden eyes"!
          • TeMPOraL 5 minutes ago
            Our cables are so good that their eye diagrams look like a photograph of a cross-section a gold analog AV connector. That is not a coincidence!
  • Onavo 3 hours ago
    I just want one that tells me the maximum voltage and current supported by a USB C cable.
    • fmajid 1 hour ago
      The Treedix will tell you that, as it is a feature of the eMarker chip (no chip means 60W).
    • contingencies 1 hour ago
      Got this recently for USD$3 on sale: https://www.aliexpress.com/item/1005006848187940.html
    • wolfi1 2 hours ago
      there are several: one that is moderately priced and which I consider myself to buy is the JOY-IT UM120
      • Onavo 2 hours ago
        Thanks, why do you prefer that particular model?
        • wolfi1 1 hour ago
          I wanted to have a model which tells me the modes which are supported and which is actually selected for a reasonable price and which I can order at a reasonable trader. this model seems to do the trick
  • Eisenstein 1 hour ago
    Hopefully they used connectors with a high mating cycle rating.
  • Modified3019 2 hours ago
    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.