IOGEAR Thunderbolt 3 20Gbps Cables REVIEW

Thunderbolt as a technology standard was first released in 2011 under the name Light Peak. Thunderbolt combines PCI Express and DisplayPort into two serial signals and also provides CD power all in one cable. It’s a powerful format and one that has gone through several evolutions. The most current version of this technology is Thunderbolt 3. It uses the same connectors as Type-C USB and is regularly found on Apple computers — namely their MacBook Pro series. Thunderbolt 3 is designed for maximum performance and can require a cable to be “active” in order to achieve the highest specs.

Even though the highest specs are found with the shortest versions of the cable (0.5m), the longer cables are sometimes an essential part of a set-up. There are many third party cable manufacturers that are trying to sell and market their cables because they are budget-friendly and I would urge to you only invest in Thunderbolt 3 cables from ‘known’ cable designers. On company I do trust is IOGEAR. They design and manufacture many different Thunderbolt 3 devices including cables and docks and their products have always been reliable to me.


The Thunderbolt 3 20Gbps Cables from IOGEAR are optimized to provide twice the video bandwidth than standard USB, power delivery, and four times the data transfer than standard USB. The TB3 cable is backwards compatible with USB 3.1 Gen 1 and 2 devices. When connected to USB-C devices, the TB3 cables can only transfer up to 10Gbps. The cable has the power to transmit audio, video, data, and power through a single cable. Users can also daisy chain up to 6 devices using one single Thunderbolt 3 port on your computer.


  • Certified by Thunderbolt Organization
  • Maximum speeds up to 20Gbps with Thunderbolt 3
  • Power delivery up to 100W (20V@5A) using an E-marker chip
  • Compatible with USB-C Gen2 10Gbps / Gen1 5Gbps
  • Single 4K @60Hz or dual 1080P @60Hz
  • Daisy chain up to 6 Thunderbolt devices


When it came to testing these lovely cables, I thought I would do it two ways. First, I would see if they would work to connect my laptop to a USB-C dock and second, I would connect them to a Thunderbolt 3 external hard drive to see how fast data would transfer. The dock I opted to use is the Kensington SD2000P Nano Dock. The dock is said to be cross-platform compatible and will work with any laptop equipped with USB-C or Thunderbolt 3. So, I unplugged the USB-C cable that comes with the dock and replaced it with the IOGEAR Thunderbolt 3 20Gbps Cable (1m). This test seemed to work very well. The cable was able to make a solid connection between the dock and the computer. The external monitor and keyboard I had connected through the dock worked without any issues and the laptop was receiving a charge from the PD function of the cable, too.

Next, I pulled out the G-Drive Mobile Pro SSD Portable Hard Drive. This is a special external hard drive because it is designed to work with Thunderbolt 3 as its main means of connectivity. It came with an active TB3 cable and had an impressive read/write speed of 2324/1102 Mbps. I decided to run the same speed test using Blackmagic Disk Speed Test with the passive cables. Prior to testing the cables with this drive, I would expect to get around half of the read/write speed that I got with the active TB3 cable given that it provides the maximum data speed at 40Gbps. I was surprised to find that these were the results.

CABLE LENGTHWRITE SPEEDREAD SPEED0.5m1102.4 Mbps2324.0 Mbps1.0m931.9 Mbps1249.9 Mbps2.0m1108.8 Mbps1266.8 Mbps

The two longer cables had very close to the same READ speed, but differing WRITE speeds and while the READ speed was about 46% less than the READ speed of the active cable the WRITE speed was nearly the same for all three. It was definitely an enlightening test and an interesting experiment to see how the passive cables fared against the active one.


For more information, visit IOGEAR Thunderbolt 3 20Gbps Cable.
Find IOGEAR on Facebook and Twitter.


Originally published at on April 2, 2019.



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