Knowledge Base

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. Please see the chart below on which systems were designed with 2 lanes and which were designed with 4 lanes.

Platform Lanes of PCIe capable via Thunderbolt 3 port
Precision 3510 * 4 lanes
Precision 3520 * 4 lanes
Precision 5510 2 lanes
Precision 5520 2 lanes
Precision 7510 4 lanes
Precision 7520 4 lanes
Precision 7710 4 lanes
Precision 7720 4 lanes
XPS 12 2-n-1 2 lanes
XPS 13 9365 2-n-1 4 lanes
XPS 13 9350 2 lanes
XPS 13 9360 2 lanes
XPS 15 9550 2 lanes
XPS 15 9560 2 lanes
Latitude 7275 4 lanes
Latitude 7285 4 lanes
Latitude 5570 * 4 lanes
Latitude 7370 4 lanes
Latitude 7280 4 lanes
Latitude 7480 4 lanes
Latitude 5480 4 lanes
Latitude 5580 4 lanes
Alienware 13 R2 2 lanes
Alienware 15 R2 4 lanes
Alienware 17 R3 4 lanes
Alienware 13 R3 4 lanes
Alienware 15 R3 4 lanes
Alienware 17 R4 4 lanes

* Only select configurations have Thunderbolt 3 ports

Thunderbolt 3 ports can be configured with 2 or 4 PCIe lane designs. Please 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 will 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 40Gbps of bandwidth depending on what devices are attached to the TBT dock.

Port Version Throughput Output
HDMI 1.4 10.2 Gbps Up to 4K2K @ 30Hz true color
Mini Display Port 1.2 Up to 16 Gbps per lane Up to 4K2K @ 60Hz
Full Size Display Port 1.2 Up to 16 Gbps per lane Up to 4K2K @ 60Hz
RJ-45 IEEE 802.3 10/100/1000 Mb/s
USB (2) 2.0 Type A 480 Mbps 5V @ 500 mA, 2A Peak
USB (2) 3.0 Type A 5 Gbps 5V @ 900 mA, 2A Peak
USB w/Powershare (1) 3.0 Type A 5 Gbps 5V @ 2A Power Share
USB Type-C Thunderbolt™ Gen 3 Up to 40 Gbps Up to 60W*

For more information please visit the link:

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

Article ID: QNA44089

Last Date Modified: 01/12/2018 09:16 AM

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