Apple's Thunderbolt 4 Pro cable design revealed under CT scan

Lumafield used a powerful X-ray CT scanner to determine why Apple's Thunderbolt 4 Pro cable is $129 compared to Amazon's cheaper USB-C offerings.

Apple's costly Thunderbolt 4 Pro cable has come under a lot of scrutiny since its debut in 2022. A previous teardown showed exactly why the cable is so expensive with its complex engineering.

A company called Lumafield used its Neptune industrial X-ray CT scanner to get a closer look at the Thunderbolt 4 Pro cable and some of the cheaper options on the market. As the teardown showed, the cable has an incredible level of complex engineering unmatched by the other cables scanned.

The Thunderbolt 4 Pro cable is rated for 100W power delivery and 40 Gbps data transfer speeds. The CT scans reveal Apple went all out with a nine-layer PCBA that utilizes all 24 pins for connection.

Compared to an Amazon Basics USB-C cable costing around $10, it's a masterpiece of engineering. The Amazon Basics cable is rated for 60W and data transfer speeds at 480 Mbps.

It has 12 pins instead of 24, with eight of them jumped across for cost-cutting. This is a lower-spec cable, so the cheaper construction and engineering are warranted, but it helps show exactly why Apple's design costs more than ten times as much.

This $5 cable lacked a PCBA. Image source: Lumafield

Other USB-C cables examined by Lumafield showed incredibly poor construction and engineering. One $5 option lacks a PCBA entirely, with connectors running straight to the wire.

Check out the detailed CT scans and an interactive application for viewing them on Lumafield's website.

The $129 Thunderbolt 4 Pro cable is 1.8 meters, a length many competitors offer. Apple continues to be the only reputable vendor with a 3 meter Thunderbolt 4 cable priced at $159.

29 Comments

fahlman 706 comments · 22 Years

About 1 year ago

Why does a rocket cost more than a paper airplane?

tht 5592 comments · 23 Years

fahlman said:

Why does a rocket cost more than a paper airplane?

Hmmm... there have been many a rocket whose paper was and is more expensive than the rocket itself? ;)

Yes, the media headlines for this article (which will go to multiple outlets) has dialed up the clickbait as much as possible.

mikethemartian 1485 comments · 18 Years

It costs that much simply because of what it is capable of doing and it is worth it. In an RF lab you can pay thousands of dollars for a phase length matched pair of passive cables for high frequencies. Those passive cables are more versatile since they can transmit arbitrary analog waveforms and not just digital streams that meet USB/Thunderbolt specifications but nevertheless $129 for 40 Gbps is a great deal.

MplsP 4020 comments · 8 Years

Wait… you mean that engineering and quality actually cost something?

darkvader 1146 comments · 15 Years

Because Apple likes to charge highway robbery prices for cables. They always have.

The chances that's in any way significantly different than any other Thunderbolt cable are ZERO. It's a standard, anybody building a cable is going to use a similar design.