Here's why cables for Thunderbolt 4 and 5 ports cost so much

There's a lot of advanced tech inside each cable. For example, Thunderbolt 5 supports up to 80 Gbps of bidirectional data transfer — and can transmit up to 120 Gbps (while receiving at 40 Gbps) in boost mode. That's fast enough to move 1TB of data in just a few minutes. (With USB 2.0, that same process could take several hours.) Meanwhile, the older Thunderbolt 4 standard supports a (still zippy) 40 Gbps in either direction.

Certified Thunderbolt 5 cables can support 140W charging, with some supporting up to 240W via USB Power Delivery. And Thunderbolt 4 cables commonly support up to 100W of charging.

If you need one cable to handle all your data and power needs, Thunderbolt is the way to go. But at those speeds, even minor interference can mess with the signal. So, longer cables are often "active." (That means they have IC chips to maintain the integrity of the signal over distances.) That includes retimer chips that clean up and refresh the signal as it travels, so it can arrive clearly at the other end.

The cable itself isn't doing all of this. (Thunderbolt controllers in the connected computer and accessories handle the heavy lifting.) But the cable has to be engineered to carry those signals without errors.

Relatively speaking, the USB-C cables you have lying around the house are dinosaurs. Many of those only support USB 2.0 speeds. Even USB 3.2 Gen 2 tops out at 10Gbps. That's plenty for, say, moving some documents, music files or photos, or running a lower-resolution display. But Thunderbolt is data transfer (and overall connectivity) on steroids.

Thunderbolt 5 can output to multiple 8K displays or extremely high-refresh gaming monitors (up to 540Hz). It supports DisplayPort 2.1 and PCI Express Gen 4 — the latter ideal for external GPUs (eGPUs). They're great for high-speed SSDs, too. And unlike basic cables, you can link multiple Thunderbolt devices in a daisy chain. Part of what you're paying for is the advanced tech that enables all of that.

Somewhat confusing the matter is USB4, which is partially based on Thunderbolt 3 technology. USB4 can reach 40 Gbps, the same as Thunderbolt 4. And USB4 V2 hits 80 Gbps, matching Thunderbolt 5. The main difference? Well, that brings us to the next point.