Does anyone recommend software that tests USB and Thunderbolt cables?
Is any software a good substitute for a hardware cable tester?
Has anyone used WhatCable?
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I am using the free version which is informative. A little TOO much info, maybe.
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It depends on what you’re testing for.
If you just want to measure available bandwidth and see the capabilities a cable reports to system software, an app like this might work.
But a proper tester does more than that. They should check:
- Make sure all the pins on one end connect to the correct pins on the other end.
- If some lines are omitted, ensure that the result is standards-compliant (e.g., a USB 2.0 cable using type-C connectors).
- Check impedance and capacitance on all the lines.
- Run various-frequency signals through the lines to make sure the signal clarity is within spec. So-called Eye pattern tests, performed with specialized tools or with suitable oscilloscopes.
These kinds of tests can’t be done with software alone. Standalone test equipment will be required.
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I think I will try the software. I have at one occasion bought USB-C cables that were supposed to be USB 3.1/3.2 compatible but when used only provided USB 2 transfer speeds. I only checked the hard drive speed using Blackmagic’s disc speed tool and that was sufficient to determine that the cables did not work, but not really why..
I just bought my first cable tester. Seems to work well. Not industrial grade fit and finish, but it seems good for occasional use. Used it to go through my pile-o-cables to see which were good, and what the capability of each was. I put a little label on each with the results. I didn’t do a ton of research, so there may be better ones out there, or better prices than what Amazon offers, but here’s the one I got: Treedix USB Cable Tester with 2.4" Color Screen for eMarker Reading, PD 3.0/3.1 Detection, Resistor and Continuity Check, Compatible with Lightning, Type-C, Micro-B 2.0/3.0, and Mini-B Cables: Amazon.com: Industrial & Scientific
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I have installed the (free) app on my Mac Studio and my Mac mini (used as a file server) and it did detect a “slow” cable I was using on the Mini to connect to a Dock (and two SSD drives). I replaced that cable and everything is fine now. So, it is useful. I buy quality cables - lately TB certified cables - so this was a surprise.
It’s free, so why not?
David
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I’m curious. Did you have many cables that were not good or did not perform to expectations?
I have also bought “USB 3” cables that top out at 480 Mbps.
It is important to remember that the version of the USB spec is meaningless, because the newest specs include all the older specs. The spec revision will define how a cable needs to be built in order to achieve a particular speed, but it does not mandate that any particular speed actually be supported.
The only terminology that is reliable (assuming the manufacturer isn’t just fraudulent) are the data-rates and their corresponding buzzwords:
- Low Speed. 1.5 Mbit/s.
- Full Speed. 12 Mbit/s.
- Hi Speed. 480 Mbit/s.
- SuperSpeed. 5 Gbit/s.
- SuperSpeed+. 10 Gbit/s.
Note that the USB forum stopped using buzzwords beyond this point, and in general, they now recommend using only bandwidth numbers and power capacities for anything faster than High Speed.
Note this infographic from usb.org:
The top row of icons is the old buzzword-based branding, but the bottom two rows are what they now recommend. Products that don’t use official branding are probably not certified and may not comply with anything at all.
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Actually, to my surprise, I found no “dead” cables. There were many that transmitted power only, but I can’t say for sure that they were ever intended for data. Only a couple tested above USB2, but again, not really a surprise, and can’t say for sure they should have been higher.
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Well.. it was clearly marked to support up to 20 Gbit/s. My Mac would only support 10 Gbit/s but I didn’t expect lousy USB 2 speeds. From a dedicated charging cable that would of course have been the case.
And you are correct that there doesn’t seem to be any official USB markings. Amazingly most other reviewers are giving it 5 stars, but a lot of them seems to just have rewritten the product description so they are perhaps made with an AI or just put there to raise the verdict
Don’t by this
I have a few of these. They came with devices and were documented as “charge cables”. I try to avoid those wherever possible.
It could be a defective unit. Or it could be a scam. No way to know unless you can return it and try another one.
If you know anyone with a cable tester (even a cheap one), you can check it pretty quickly. A USB 2.0 cable will only wire the four ground lines (all tied together), the four VBUS power lines (all tied together) and the two data lines (D+/D-). So there may only be four wires running through that cable.
A cable capable of running in SuperSpeed modes (5 Gbit/s or faster) will have 18 wires, connecting almost all (but not all) of the pins. These will include at least all of the USB 2.0 pins, plus four differential pairs.
See also Wikipedia: USB-C Cable Specification and USB-C Pin usage in different modes.
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I was really hopeful when I came across this. Whilst it is a “universal” app (so runs on my 2019 iMac), it requires an Apple Silicon Mac to detect cables on the USB-C ports. So detects nothing on this iMac.
DOA for me. It only works with AS Macs. I have Intel.
I’m finding WhatCable (paid) admirable – since these days every device one acquires comes with a couple of cable—which we then plug into a hub. And we have a draw full of spares.
Whooof. As we’d expect, OWC and similar cables test out as device ratings indicate they should, but running through some of my others has lightened the load… very useful utility, especially for power cables…
Some helpful information about WhatCable here: Michael Tsai - Blog - WhatCable 1.1.7
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I didn’t know about this tracking capability:
Name a cable and it tracks how the cable actually performs over time, so you can spot the one that has started misbehaving. No more guessing why a cable charges slow or refuses to drive your display.
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Nothing like curiosity to dig up what you’d rather not have known. So what does one make of this:
The cables are identical Apple TB3 cables w/ Apple TB3-TB2 adapters.
The Sonnet, the first device is (or was advertised) as TB2. The second, the RocketStor, never claimed more than TB1. Is it the cables, the adapters, false claims…
Not clear that buying a license will provide anything more useful.
I bought the Treedix. A cable from Chubby Cable, which is usually a reliable source, turned out to be the problem: my wife’s car and CarPlay were losing sync. The dealer recommended a wireless CarPlay dongle, but since the problem went away when I used a new cable, I ignored it.
With the number of cables I have and the random problems with some (why I have a lot of cables 
), the tester will be used often enough to justify the cost. -thanks
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