https://www.tindie.com/products/bittradeone/usb-cable-checke...
But when I care about performance, I just get a cable from Anker and don't worry too much about it.
BUT THE MOST IMPORTANT THING IS: WHERE CAN I GET ONE OF THOSE TINY GREEN MILK CREATES IN THE PHOTO?
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
If you care, then care enough to do small, practical things for yourself. A little loop of tape. Paint marker. Even just sorting them into drawers/boxes/whatevers by type.
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: https://randsinrepose.com/guides/usb/usb-guide.html
Apple sells this $30 (0.5m) CalDigit cable https://www.apple.com/shop/product/hs9d2zm/a/ and this $70 (1m) Apple cable https://www.apple.com/shop/product/mdw94am/a/
There's also some interesting discussion of Thunderbolt 5 cables on reddit (6 months ago): https://www.reddit.com/r/UsbCHardware/comments/1r84q54/
I just bought a couple of their Thunderbolt™ 5 cables. They seem like a reputable company that would make their cables true-to-spec. Thanks in advance!
Support allowed me to send it back for replacement as a "one-time exception", though I was well within the common 2-year warranty period in the EU.
I was quite impressed by GlobTek (available at Digi-Key) and have been buying those when I need something nice. Their USB-C line are some of the best I've seen, not that I'm a connoisseur.
I can't say I've seen it on USB-C-esque cables (except maybe a thunderbolt cable a while back?) but I've seen some cables use a type of aluminum or mylar-looking foil between the outer rubber sleeve and the inner sleeves and wires.
A USB-C cable really should be shielded. Here's a cross-section I took of a nice full-featured USB-C cable: https://ibb.co/svR5Yvyr . You can see the VBUS/GND (fat red/black), the SS pairs (white plus red/blue/yellow/brown, each one foil shielded on this cable), the USB 1/2 pair (white/green), and then the CC and SBU stuff is the remaining wiring. Notice how not just the whole thing is braid+foil shielded, but the SS pairs are individually shielded; that's really important at these speeds, and what you want to see on a good cable.
Compare with two USB 2.0 cables: https://ibb.co/BHz4v1mx and https://ibb.co/GfpJmgbx ; the first one has the shield braid, as it should, but everything else is nicer on the second one. Cables!
Phones and macbooks have it done right where the outer portion of the port is built in to the device body, but most other devices don't do this.
If you want to test bandwidth, that's a five- or six-figure bit of gear.
Resistance measurements can cursorily test claims of 240W but resistance changes with temperature which changes with current...so unless your tester puts 5 amps down the wire for 5 minutes and then tests resistance it's not a very good test.
For home use I've ended up treating real capability as an empirical property of the specific cable+port+device combo: does this exact cable drive this monitor at the mode I want, under load, for an hour? If yes, it gets a colored heat-shrink band and never leaves that use case. Everything else is a phone/charge cable until proven otherwise.
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.
The issues come into play with going beyond that. USB 3 speeds? USB 4? Thunderbolt? DisplayPort (4k uncompressed video!) alt modes? 240W charging? These are all practical things that regular people use USB C cables for every day, but they require very specific support from the cables themselves, and that support is widely varied.
Your cables work fine for what you're doing with them, but you're really barely scratching the surface of the kinds of things that can be done. :)
My desktop “server” with two 4K monitors doesn’t even reach 240W !
All of these “usb sucks” posts are about using multiple 4k 120hz monitors dasychained while pumping 140w and a handful of other dongles hanging off which pushes usb to the limit and requires carefully selecting the highest quality cables.
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), connected to a Pro Keysight Infiniium oscilloscope ($258,809) is the proper way to test it. https://www.keysight.com/au/en/product/N7018A/type-c-test-co...
This is the one I use and I quite like it. I've had it for a little over a year and a half. I used it to sort (or trash) all my cables and to test new incoming cables.
Anyway, it's definitely better than having nothing, and tests resistance as well. I tossed a couple low value/duplicate/high resistance cables because I've got too many just lying around causing clutter. Also helped 'confirm' my good (e.g. TB4+) cables that weren't labeled clearly are indeed good cables - granted, this is only as dependable as the marker chip the manufacturer added.
It's only $14.
It even offers test pads you can use to test the cable with a much more expensive multimeter.
To actually test for the bandwidth those are hell expensive.
Now people starting test for the chip, those scammers will install more fake chip ...
The same principles that worked for auditors tracking risk compliance in the 2000's now work for humans tracking AI-output risk compliance in 2026
Regardless of tests they do charge my most energy hungry devices and everything else
Many of us are privileged enough to make our lives easier in this way and haven't thought about it
> Your no-brand 480Mbps USB 2.0 cable is indistinguishable from the super-fast USB 4 cable that can move 40 gigabits (around 5 gigabytes) of data every single second.
One of those is way thicker than the other, at least.
I would love for something to force a speed and power rating on USB-C plugs.
I bet there's at least one brand with extra–thick plastic insulation.
This already exists. Cable makers can certify their cables and mark them with their data speed and wattage.
I buy only certified, marked cables. If I see an unmarked cable, I assume it’s slow and low-powered…which is good enough for some things.
The cables are supposed to be labelled with their maximum speed (5, 10, 20, 40, or 80 Gbps or nothing if no data) and maximum wattage (60W or 240W).
HOWEVER, I don't remember ever seeing a cable with such a label. I'm sure they exist, but I don't see them. Requiring products to be labelled, and treating mislabelling as fraud, could mostly solve this. It's definitely a real problem.
There are too many manufacturers to hunt. Basically USB-IF needs to stop almost all shipments in the world. That's not going to happen.
USB spec is completely open and free to obtain. While it allows people to develop and DIY many things, it also attracts bad manufacturers like flies.
Good certified cables with correct markings exist. There are companies like Cable Matters or Startech who bother to actually certify their cables and get USB-IF TIDs. They do cost you quite a bit money though. Here are some:
https://www.cablematters.com/pc-1532-123-usb-c-20-charging-c...
https://www.cablematters.com/pc-858-123-usb-if-certified-usb...
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.
This is what happens when the spec is awful and says "the cable must do 480Mbps, or it must do 40Gbps, or... whatever, have fun!"
The best you can get is TB5 (240W, up to 120 Gbps data transfer) and at 1m long they’re $32 or so from CableMatters. Those are admittedly somewhat thicker, but not stiff.
I wish there was a higher baseline data transfer mandated for usb-c. Sure, 40gbps isn’t needed for all cables, but is some piddly 5gbps too much to ask? We had usb 2.0 speeds back when CPUs just barely entered 1 GHz range, it’s practically ancient technology. Admittedly most people never transfer any data over usb, but with this logic we might as well have usb-c that does charging only. Being able to pick any cable and have 5 gbps baseline means that any usb-c cable is fundamentally usable, if slow. 480 mbps is… ugh.
I don’t have an issue with 60W being the baseline, it’s enough for most laptops and the average GaN charger is 65 W (or less) anyway.
5gbps means you add 8 additional wires to every cable, and also would require that both devices on each side implement 5gbps PHYs for their USB (if you mandated it on devices too). It’s a large cost, especially when you’re talking about billions of cables.
Do we do this for every new version and combination of versions for USB? USB-PD? Thunderbolt? DisplayPort?
Then USB is forever frozen in time, unless we start using new connectors.
This was the tradeoff we got when standardizing on one connector. The protocol versions change (USB, USB-PD, Thunderbolt), the cables that go between each connector change based on the needs of the spec they supports. But the connectors stay the same.
In my opinion, this was a poor tradeoff and now we’re living in the hell we asked for.
If you want every cable to support the latest and greatest of whatever exists as of right now, you can do that. By all means, buy Apple’s USB-C Thunderbolt 5 cables. They’ll run you $70 apiece but you’ll be buying a cable that makes no compromises.
My personal approach is to just use whatever cable came with the device for anything for which that’s convenient and plausible. For mobile devices with relatively limited charging speeds over USB-PD and for which portability and durability are typically important, I buy the latest Apple woven cables. For high-bandwidth devices I spend the big bucks on the Apple Thunderbolt 5 cables. I discard any cables of unknown provenance.