Thunderbolt 3 40gbps Data Transfer Rate

Customers using Dell systems with a Thunderbolt 3 port may report they are unable to achieve data transfer rates up to the maximum 40gbps. Some customers may report the data transfer speeds vary depending on the system they are testing on.

Customers may also report that the system only has 2 lanes of data and not the expected 4 lanes. See the chart below on which systems were designed with 2 lanes and which were designed with 4 lanes.

Note: Any system that is not listed in the article should be 4 lanes as Intel has standardized to 4 lanes.

* Only select configurations have Thunderbolt 3 ports.

Thunderbolt 3 ports can be configured with 2 or 4 PCIe lane designs. Note that Alpine Ridge uses separate inputs for Display Port 1.2 data (DP stream is not part of PCIe traffic).

Thunderbolt 3 bandwidth is shared bandwidth which means all connected devices use the bandwidth for all protocols that transfer through the same Thunderbolt 3 cable (DisplayPort over USB-C traffic and PCIe traffic such as USB, Ethernet, and Audio). Below is a chart that can help explain how different items can use the 40gbps total bandwidth. The Dell Thunderbolt TB16 dock can utilize up to the full 40 Gbps of bandwidth depending on what devices are attached to the TBT dock.

For more information please visit the link: https://thunderbolttechnology.net/sites/default/files/Thunderbolt3_TechBrief_FINAL.pdf

NOTE: Systems with the 2 lane design will only support up to 20gbps data transfers over PCIe devices such as external hard drives or PCIe video cards. Systems with 4 lane design will support up to 40gbps of data transfer over PCIe depending on the device in use.

If you have further questions about this article, contact Dell Technical Support.