How we test USB-C cables at PCWorld

USB-C cables get no respect. Most individuals store for the lowest-priced cable and name it a day beneath the belief that they’re all the identical. They’re not although, and right here’s how I weed out the nice cables from the unhealthy cables within the evaluate course of.

For the report, the overwhelming majority of PCWorld’s cable checks are carried out on cables I bought retail, however sometimes, I’ll settle for cables immediately from producers to expedite the evaluate course of. Our cable evaluations are literally bodily carried out on the cables and usually are not regurgitated from studying different evaluations or studying user-generated evaluations from customers.

Further studying: Best USB-C cables

Examine the advertising claims

Cables are commodities no totally different than salt, rice, or meat, however as we all know that doesn’t imply they’re all the identical. Unlike {hardware}, it’s straightforward for a corporation to fluff up a product in its promoting or advertising, so we fastidiously study the efficiency and have claims of every cable to see if it matches actuality. Respected manufacturers are likely to play it secure (however even they’ll stretch the reality a bit), whereas smaller manufacturers typically make claims which might be flat out flawed. Whether that’s on account of a translation problem, confusion with an advanced topic, or flat-out misrepresentation isn’t judged — however I name it out after I see it.

Gordon Mah Ung

Gordon Mah Ung

Gordon Mah Ung

Check certifications

If the cable claims to have USB Implementers Forum certification or UL certification, I’ll question each organizations’ databases or contact the group in an try to confirm the declare.

Examine the eMarker

Higher-performance charging or information switch USB-C to USB-C cables characteristic an embedded eMarker chip that tells the cellphone, pill, laptop computer, and charger simply what the cable helps. I learn the eMarker’s information utilizing a Charger Lab KM003C and examine it to the cable’s advertising claims. Usually they need to match, however some small-brand corporations get the eMarker information flat-out flawed, which ought to provide you with pause about buying them.

Gordon Mah Ung

Gordon Mah Ung

Gordon Mah Ung

Weigh it

Although it isn’t good, I’ve discovered that one straightforward strategy to gauge the standard of a cable is to easily weigh it. Sure, the outer coating will be an affect within the weight, however you’d be shocked at how typically a cable that has poorer resistance and fewer options additionally finally ends up weighing much less. Again, it’s not a predictor of a cable that received’t perform, however a lighter cable usually means greater resistance and may portend a shorter life span if abused by the proprietor on account of its thinner wires.

Test resistance

To gauge the standard of the cable, I take advantage of a four-wire, milliohm meter hooked up to the cable utilizing USB breakout boards on the VBUS and floor wires. Subtracting the added resistance of the breakout board, I can simply see which cables are constructed with higher wiring. For instance, the Belkin BoostCharge 240-watt braided cable measures in at 62 milliohms of resistance versus 209 milliohms for a super-budget JSAUX USB-C cable I checked out lately. That’s a big distinction between the cables (decrease is best) and it tells us the Belkin BoostCharge’s greater price ticket pays in charging high quality and certain longevity as thicker wires ought to stand up to extra abuse in idea.

Gordon Mah Ung

Gordon Mah Ung

Gordon Mah Ung

Load take a look at

Charging might be the primary characteristic used on all cables. To take a look at that, I load take a look at the cable utilizing a USB Power Delivery 3.1 set off related to a man-made load tester and stress take a look at the cable for at least 30 minutes. As a backup to that take a look at, I additionally join the cable to a laptop computer and test if it’s in a position to attain the laptop computer’s 100-watt cost necessities.

One weak spot with this take a look at is I’ve not discovered any chargers that help 240 watts (nor any laptops). That means my present load take a look at is restricted to 100 watts. The load tester I take advantage of can be restricted to 180 watts as nicely. Hopefully that adjustments as 240-watt {hardware} turns into extra frequent in the future. I’m within the strategy of sourcing a 180-watt USB-PD charger, however that additionally falls nicely in need of the 240-watt most.

Gordon Mah Ung

Gordon Mah Ung

Gordon Mah Ung

Examine the wiring

There will be as much as 18 wires inside a “full featured” USB-C cable and 24-pins within the plug. The totally different wires allow totally different capabilities comparable to monitor help and high-speed information switch pace. I take advantage of two totally different continuity testers. The first is a BitTradeOne ADUSBCIM USE Cable Checker 2. It’s my favourite cable tester and tells me whether or not a cable helps fundamental USB information switch speeds as nicely what degree of USB SuperSpeed is supported. It additionally does fundamental resistance measurements and IDs if there’s an eMarker inside the cable.

The second continuity meter is a CaberQU USB-C cable tester that visually shows connections for all 24 attainable mixtures in a USB-C to USB-C cable. I significantly just like the CaberQU as a result of the documentation is great for somebody occupied with what the pins in a USB-C cable carry out.

I ought to notice that one drawback with easy continuity testers is that whereas they take a look at for the presence of the wires, they can’t display for the likelihood that the producer has really constructed the cable incorrectly, and fall quick for testing of energetic USB-C cables.

Gordon Mah Ung

Gordon Mah Ung

Gordon Mah Ung

Data take a look at

If a cable maker has in some way wired up the connections for a cable incorrectly, which a continuity tester can not detect, one strategy to test that in the true world is definitely to make use of the cable. For that take a look at, I join a USB-C exterior NVMe drive to a laptop computer and measure the switch pace utilizing a drive efficiency benchmark. This is extra crucial on a full-featured USB-C cable, which might attain from 10Gbps to 40Gbps switch speeds, and fewer crucial on fundamental charging cables which might be restricted to a sluggish 480Mbps.

Gordon Mah Ung

Gordon Mah Ung

Gordon Mah Ung

Video take a look at 

For full-featured cables that help video output, I join an exterior USB-C high-refresh fee panel utilizing the cable to make sure that it’s once more wired up accurately, and can accurately perform with an exterior monitor. This take a look at will not be carried out on fundamental charging cables, which won’t perform with displays.

Thunderbolt take a look at

For full-featured cables that help high-speed information transfers, I carry out a switch take a look at utilizing a Thunderbolt 3 drive related to a laptop computer to make sure it’s wired up accurately and notice the switch efficiency. This take a look at will not be carried out on fundamental charging cables, which don’t help Thunderbolt signaling.

USB4 take a look at

With USB4 quickly changing into the norm, I additionally take a look at PC information transfers utilizing a USB4 drive enclosure to make sure it’s wired up accurately. This take a look at will not be carried out on fundamental charging cables, which don’t help quick USB4 signaling.

To discover the very best USB-C cable in your wants, and to be taught which cables to keep away from, see PCWorld’s roundup of the best USB-C cables.