Three Thunderbolt 3 cables put to the test

Thunderbolt 3 cables come in all prices and tastes, but a rule of thumb is that the ones that are under 1m in length are passive cables. The ones you buy of over 1m in length are active cables, meaning they have a long connector at the end that houses the electronics to carry the signal over longer distances. With Apple now selling the 2m braided nylon Thunderbolt 3 cable it includes with your Apple Pro Display XDR monitor separately for a whopping €150, I thought it’d be a good idea to test a number of 2m cables from well-known brands that sell on Amazon’s sites and elsewhere. I tested a Cable Matters, CalDigit and Belkin cable.

I tested these cables with a MacBook Pro, Apple’s Pro Display XDR monitor, an OWC Express 4M2 external SSD RAID and a CalDigit TS3+ dock.

The Cable Matters 2m Thunderbolt 3 cable might be the least well-known brand of the three, but it delivers what it promises. It is advertised as being capable of delivering 40Gbps Thunderbolt 3 speeds and 100W of power, as well as driving a 5K monitor. The cable is well built, with connectors that look sturdy and have rubberised sleeves on the end. In fact, the Cable Matters performed well in all my tests. The Cable Matters cable does look exactly the same as the CalDigit one, though, except for the logo on those connectors, so they’re both probably made in the same factory to the same specs. And sure enough, the CalDigit cable performed the same with exactly the same minor problems.

In terms of performance, the Cable Matters cable as well as the CalDigit became hot when using the OWC Express 4M2 for a video rendering job that ran for 20 minutes. However, this doesn’t seem to do any harm to Thunderbolt 3 cables, although I suspect the longevity of their electronic parts will suffer as a result of the heat.

The only real criticism I could have on the Cable Matters and CalDigit cables is that both their connectors seem to be a fraction too slim to fit well in some devices’ ports. It could also be that those devices’ ports are a fraction too big, but then again, the short, passive cables I tried these with all fit perfectly.

I also tested the 100W 2-meter Belkin Thunderbolt 3 cable that Apple sells in its online store. This cable has the same specs as the other two, so it doesn’t support DisplayPort or USB 3.1, and will only deliver 480 Mbps when connected to a USB-C 3.1 Gen 2 port. You should also take care to check you’re really buying the 100W cable as Belkin does also have a 60W 2m cable in its range.

That being said, the Belkin cable is well-built and it’s the only one to have differently designed connectors which were a perfect fit with whatever Type-C port I threw at it. In other words, whereas the two other cables I tested (very) occasionally sat somewhat loose in the equipment’s Thunderbolt 3 port, the Belkin cable never had that problem.

It’s also almost needless to mention with the reputation Belkin has, but this cable worked great with all the test equipment I had at my disposal. Nevertheless, even the Belkin cable doesn’t fully support the Thunderbolt 3 specs as it does not support DisplayPort video and USB 3.1 Gen 2 data transfers of up to 10Gbps.

In fact, the only 2m cable I know that pulls off that trick is Apple’s certified 40 Gbps braided nylon Thunderbolt cable, but at €149, it’s twice as expensive as the other three. Granted, Apple’s Thunderbolt 3 Pro Cable supports the full Thunderbolt 3 spec, including DisplayPort video, 100 watt charging and USB 3.1 Gen 2 data transfers of up to 10 Gbps.

Apple furthermore states that the braided nylon sheet on the cable should allow coiling without tangling, but as far as I could see, tangling isn’t a problem on any of the three cables that I tested. For that reason you should definitely not have to spend €150 on a cable that might be useless once Thunderbolt 4 is released. I asked both Apple and Intel for a comment on the latter issue but neither responded to my email messages I repeatedly sent to their PR departments.