The Thunderbolt 3 standard has been available for roughly four years now, but cable lengths have so far generally been limited to a couple of meters due to signal degradation over long distances of copper wiring. While the use of copper Thunderbolt 3 cables limits their length, it does allow for additional features like the ability to carry power and fallback use of USB modes at slower speeds.

Areca's 30-meter optical Thunderbolt 3 cable

There is an alternative to copper cables that allows for longer cable lengths, and that's optical fiber cables, which use light to transmit signals over long distances with high fidelity. While there have been optical versions of Thunderbolt 1 and 2 cables, the Thunderbolt 3 standard has been very slow in seeing optical cables come to market.

The market for optical Thunderbolt cables is relatively small given their expense and the fact that the vast majority of users have no need to run cables longer than a couple of meters, but for those who do need long cables, the wait for Thunderbolt 3 cables has been a long one.

That wait finally appears to be coming to an end, however, as we're starting to see signs of the cables coming to market. Taiwanese company Areca has recently launched optical Thunderbolt 3 cables, available in 10-, 20- and 30-meter lengths. The cables are available through B&H, but with pricing coming in at $559, $699, and $799 respectively, these are obviously only for pro-level users who absolutely need the highest performance over long distances. And remember that these cables can only carry Thunderbolt 3 data and don't fall back to USB or provide power to or from connected devices.

B&H currently lists expected availability of 7-10 business days on all three cable lengths, and Areca told me a few weeks ago that supplies were somewhat constrained as its factories were still trying to ramp production back up. Areca tells me that beyond the cables that have shown up at B&H, the company is also planning a special-order 50-meter cable and has also been considering a shorter 5.5- or 6-meter cable, although the minimal price difference between that and the 10-meter version may not make it worthwhile.

Corning's optical Thunderbolt 3 connectors

One of the major optical cable manufacturers users have been looking to for Thunderbolt 3 cables is Corning , and it appears its cables may be close to coming to market as well. One MacRumors reader let us know that Corning's cables have started appearing on websites of some European resellers like MacConsult in lengths ranging from 5.5 meters to 50 meters. Based on these listings, Corning's pricing looks like it will be starting at around the equivalent of $400 in the U.S., a bit less than Areca but still out of the range of the average consumer.

Corning tells me that while samples of its optical Thunderbolt 3 cables have been shown at trade shows over the past couple of years, it's not quite ready to officially launch them and shared the following statement:

Corning’s Thunderbolt 3 cables have not yet been launched publicly, although we have shown preliminary samples at industry events. We look forward to their launch, although a date has not been scheduled.

It seems likely that Corning is still awaiting final certification from Intel and that a distributor may have gotten a bit ahead of itself in pushing out preliminary listings to some resellers, but hopefully we can expect Corning's cables to hit the market fairly soon.

The annual NAB show in April would have been a good opportunity for Corning to launch its cables if final certification from Intel was imminent, but as with nearly every other trade show, NAB 2020 has been canceled, so we'll have to wait and see what Corning's plans are.

Optical Thunderbolt 3 cables are hitting the market just as Intel has started teasing Thunderbolt 4, although it's unclear what the differences between the two versions will be, as they appear to offer the same maximum transfer speeds. USB4 is also coming to market in the relatively near future and will essentially unify Thunderbolt 3 and USB with Thunderbolt 3's theoretical maximum 40 Gb/s speeds.