Technology: The (nearly) perfect USB cable tester does exist
blog.literarily-starved.com201 points by birdculture 4 days ago
201 points by birdculture 4 days 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.
Perhaps someday it will earn the same level of importance as charging; iOS 26 calls out slow chargers on their iPhones, so you can run to the Apple Store and buy a fast one!
They probably have to weigh potential new hardware sales against added complexity. I have counterpoints too but: I believe they try to protect users’ mental models of their ecosystem (which perhaps I appreciate when I don’t notice, and can’t stand when something is uncustomizable). Like there are enough variables they don’t trust us with as it is.
> 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.
AFAIK that's just when plugging in a USB 3 device into a USB 2 port or using a USB 2 cable.
> that's just when plugging in a USB 3 device into a USB 2 port
Dell XPS laptops (and some others) can also warn if the charger isn't providing the full wattage the laptop is rated for. This warning is an option that can be turned off in the BIOS settings.
I usually turn it off because I sometimes intentionally do day trips with a smaller/lighter portable charger which delivers 45w to my laptop which can need up to 65w due to having a discrete GPU. However, 45w is more than sufficient to charge the laptop during normal use on the Balanced power plan with iGPU. I only need more than 45w when gaming with the discrete GPU active.
I wonder if it's possible for a regular machine with two high speed ports to do a cable test by itself. Maybe it can't test all the attributes but could it at least verify speed claims in software?
Apparently the USB driver stack doesn't report the cable's eMarker chip data back to the OS. However benchmarking actual transfer throughput is the ultimate test for data connections (vs charging use cases). Unfortunately, TFA doesn't really go into this aspect of cable testing as the tester seems to only report eMarker data, which pins are connected and copper resistance.
Since a >$1,000 automated lab cable throughput tester is overkill, my thumbnail test for high-speed USB-C data cables is to run a disk speed benchmark to a very fast, well-characterized external NVMe enclosure with a known-fast NVMe drive. I know what the throughput should be based on prior tests with an $80 active 1M Thunderbolt cable made for high-end USB-C docks and confirmed by online benchmark reviews from credible sources.
There would be too many factors involved for a proper test. Many laptop USB controllers would probably not even have the capacity to run two ports at full speed simultaneously.
Even Apple now has one of those, when you plug something into the USB 2 port on the MacBook Neo.
I strongly suspected my old xps had nonstandard things going on with its USB C charger
> 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.
There is. I used to use a KVM with USB 2 ports connected to my PC's USB 3 port, to which I connected a monitor with integrated USB 3 hub to drive my keyboard and mouse. Windows would show a popup every time telling me that I should use a faster cable.
There are also popups telling me that my laptop is connected to a "slow" usb-c charger.
That’s quite a simplistic one unfortunately - USB 2 and 3 use different controllers in the PC, which it can indeed detect. The sub-flavours of 3/4 less so.
I've used all manner of archaic usb cables for data transfer when in a pinch and windows has never shown me anything at all. Could it be the external device you were connecting to triggering the windows notification?
I have seen these kinds of notifications on occasion but they are far from the norm.
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.
I suspect most users do not even realise things are slow.
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.
They also tend to hate technology, because us nerds are often unbearable.
They hate having to go through people that get them upset, in order to use their kit.
Not just tech (although it’s more prevalent). People who are “handy” can also be that way (but, for some reason, techies tend to be more abrasive).
I’ve learned the utility of being patient, and not showing the exasperation that is often boiling inside of me.
I had a programmer pushing multi-gig packages to a Meta Quest 3; and it was taking around a minute. He didn’t even think that it could be faster because he assumed the Quest or software was slow and didn’t check.
I implored him to try a different cable (after checking cables with the Treedix mentioned in TFA), and the copy went from taking over a minute to about 13s.
Its not just normal people confused.
I find some programmers (and this is presumably true of any industry) very narrow in their expertise within technology.
I think you are right, but I think what I said is also true.
People will notice some things. For example, with USB if they are using it for local backup they might notice, but with a lot of devices they will not. When they do notice, they will feel powerless.
Even if we had a wider choice, they are not well placed to pick products. There is no way they will know about details of things such as USB issues (a cable is slow, the device will not tell you if it is) at the time of purchase.
I think any of us just have to look at how many people ask us for recommendations on basic things like docks and adaptors to see how common this is. On top of that you can’t even trust what’s on the tin sometimes.
This is true of basically everything. Even trivial home maintenance people will just put up with things being broken most of the time over learning how to fix them.
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.
> so shipping with a chunky cable that doesn’t even carry decent data feels like a bizarre oversight.
USB 2.0 can support up to 480 Mbps. It’s more than fast enough for any audio stream you can send to a DAC.
Your headphones don’t need USB 3.0 5 Gbps speeds. USB 3 requires extra wires with different properties that need to be controlled more tightly, which can impact cable flexibility. If your headphones used USB 3 when they didn’t need it that would be one more thing to break and more failure modes for the cable.
A USB 2 cable with fewer conductors was the right choice for this product. The fact that you only got miffed about it when plugging the cable into a tester, not from actually using the product or cable, is good evidence that a USB 3 cable wasn’t needed.
Nobody said the headphones needed USB 3. The point is that the cable is physically thick and rigid (like something you'd expect to carry serious data) but doesn't. Meanwhile Apple ships a thinner, more flexible cable that supports the same USB 2.0 speeds and equivalent power delivery. The cable B&W chose is worse ergonomically for no functional benefit. That's the kind of mismatch the Treedix exposes.
Is there any audio you might play that doesn't fit in 400Mbps?
The point isn’t really about audio bandwidth; it’s about the cable being strangely overbuilt for what it actually does.
It’s rigid and thick, like a Thunderbolt 3 cable, yet only supports USB 2.0 speeds and fast charging for a device that doesn’t need fast charging.
Compare that to Apple’s iPhone USB-C cable which is thin, flexible, and supports the same features.
That matters because someone might grab that cable assuming it’s a “better cable”: it came with a £629 product, it’s thick and feels serious, so surely it’s capable. But it isn’t. And there’s nothing marked on it to tell you otherwise.
The whole system ends up relying on presumption, which is exactly the problem the device in the article is solving.
> The point isn’t really about audio bandwidth; it’s about the cable being strangely overbuilt for what it actually does.
The purpose of the heavy construction is to make it durable, not to carry 5 Gbps data streams to your headphones.
Unlike most USB peripherals like your printer and keyboard that get plugged in and then don’t move around, headphone cables go to your head and move around constantly. They can get pinched in drawers or snagged on corners.
Hence the more durable construction.
Apple's woven USB-C cable gets dragged around with iPhones, iPads and laptops daily and manages durability at half the thickness. Durability doesn't require rigidity... in fact for a headphone cable, rigidity is the opposite of what you want. Stiff cables tug on the headphones and transmit mechanical noise.
It’s common to add weights to headphones to make them feel premium which is bizarre since actually premium headphones tend to try very hard to reduce weight as the weight makes them more uncomfortable.
I don’t know how to fix the market especially when consumers keep rewarding these practices, and I think the effectiveness of TikTok style influencer marketing will make it worse.
I don’t think that’s what’s happening here. B&W actually reduced the weight on the Px8 S2 compared to the original, and the headphones themselves are genuinely lightweight for what they are. The cable isn’t thick to “feel premium” (it feels kinda bad); it’s thick because it’s rated for 65W+ power delivery that the headphones don’t need.
The problem is the opposite of what you’re describing, it’s not a cynical design choice, it’s a lazy one. They probably just purchased a cable for capabilities irrelevant to the product and the result is worse ergonomics and misleading physical cues about what the cable can actually do.
“I don’t think..” Ok, you’ve made a number of assumptions and we don’t share the same priors so I’m unable to follow you to your conclusion.
I think you are underestimating the importance of perceived premium combined with the pressures of cost accounting, but I do think that is pretty normal for ‘audiophiles’ which is their target market.
Which assumptions? The weight reduction on the S2 is documented and the cable’s 65W rating is what the tester confirmed.
If the argument is that B&W deliberately chose a thick cable to seem premium, it doesn’t square with them actively slimming down the headphones. B&W are primarily a speaker company, their USB-C product range is basically just a few headphones and earbuds.
More likely they just sourced a generic cable that happened to support high wattage and didn’t think about the mismatch.
Either way, we’re deep in the weeds on B&W’s cable procurement now. The root point is that USB-C is a mess. You can’t tell what a cable supports by looking at it, and even premium manufacturers are shipping cables that don’t do what you’d reasonably expect.
That’s exactly the problem the Treedix from the article solves.
My point on weight was that the market for that it is common, which is probably a stronger statement than needed. I should have made the weaker argument and said the market exists which only needs one example. The company Beats can serve as that example, this company sells the majority of premium headphones but I don’t actually know what percentage have weights placed in them. I am assuming a non trivial percentage.
You are using circular reasoning in your logic, you assume the premise is true and from there you derive your evidence.
I would contend that someone thought about it and decided to go with the cheaper option because they could get away with it. I would consider my assumption to have more grounding given my experience with manufacturing and cost accounting.
You’ve gone from “companies add weight to feel premium” to “they went with the cheaper option because they could get away with it.” Those are opposite explanations. But either way, the cable doesn’t do what its physical presence suggests, nothing on it tells you otherwise, and that’s the entire point of the device in the article.