Thunderbolt 3 40gbps Data Transfer Rate
Summary: Learn about Thunderbolt 3, transfer rates on Dell systems, its features, and frequently asked questions about Thunderbolt 3.
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Table of Contents:
- What is Thunderbolt Technology?
- What is Thunderbolt 3 Over USB-C?
- Key Features of Thunderbolt 3 Over USB-C
- Thunderbolt 3 40gbps Data Transfer Rate
- Frequently Asked Questions
What is Thunderbolt Technology?
Thunderbolt (previously called Light Peak) is a hardware interface that combines data, video, audio, and power in a single connection. Thunderbolt combines PCI Express (PCIe) and DisplayPort (DP) into one serial signal, and also provides DC power, all in one cable.
Thunderbolt 1 and Thunderbolt 2 use the same connector as mini-DP (DisplayPort) to connect to peripherals, while Thunderbolt 3 uses a USB-C connector.
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Thunderbolt 1 and Thunderbolt 2 (using a mini-DP connector) |
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Thunderbolt 3 (using a USB-C connector) |
What is Thunderbolt 3 (Thunderbolt Over USB-C)?
Thunderbolt 3 brings Thunderbolt technology to USB-C at speeds up to 40 Gbps, creating one compact port that does it all - delivering the fastest, most versatile connection to any dock, display, or data device like an external hard drive. Thunderbolt 3 uses a USB-C connector/port to connect to supported peripherals.
Key Features of Thunderbolt 3
- Thunderbolt, USB, DisplayPort, and Power Delivery over a single USB-C cable (*features vary between different products)
- Thunderbolt 3 uses USB-C connector and cables - It is compact and reversible.
- Supports Thunderbolt Networking (*varies between different products)
- Supports up to two 4K displays
- Thunderbolt 3 supports speeds up to 40 Gbps.
Note: Data transfer speed may vary between different devices.
- Low latency
- DisplayPort 1.2 - compatible with existing DisplayPort monitors, devices, and cables.
- USB Power Delivery - Up to 130 W on supported computers.
Thunderbolt 3 40gbps Data Transfer Rate
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 that the data transfer speeds vary depending on the system they are testing on.
You may also report that the system only has two lanes of data and not the expected four lanes. See the chart below on which systems were designed with two lanes and which were designed with four lanes.
Note: Any system that is not listed in the article should be four lanes as Intel has standardized to four lanes.
| Platform | Lanes of PCIe capable using Thunderbolt 3 port |
|---|---|
| Dell Precision 3510 * | Four lanes |
| Dell Precision 3520 * | Four lanes |
| Dell Precision 5510 | Two lanes |
| Dell Precision 5520 | Two lanes |
| Dell Precision 7510 | Four lanes |
| Dell Precision 7520 | Four lanes |
| Dell Precision 7710 | Four lanes |
| Dell Precision 7720 | Four lanes |
| XPS 12 2-n-1 | Two lanes |
| XPS 13 9365 2-n-1 | Four lanes |
| XPS 13 9350 | Two lanes |
| XPS 13 9360 | Two lanes |
| XPS 13 9370 | Four lanes |
| XPS 15 9550 | Two lanes |
| XPS 15 9560 | Two lanes |
| Latitude 7275 | Four lanes |
| Latitude 7285 | Four lanes |
| Latitude 5570 * | Four lanes |
| Latitude 7370 | Four lanes |
| Latitude 7280 | Four lanes |
| Latitude 7480 | Four lanes |
| Latitude 5480 | Four lanes |
| Latitude 5580 | Four lanes |
| Alienware 13 R2 | Two lanes |
| Alienware 15 R2 | Four lanes |
| Alienware 17 R3 | Four lanes |
| Alienware 13 R3 | Four lanes |
| Alienware 15 R3 | Four lanes |
| Alienware 17 R4 | Four lanes |
| Inspiron 7577 | Four lanes |
* Only select configurations have Thunderbolt 3 ports.
Thunderbolt 3 ports can be configured with 2 or 4 PCIe lane designs. 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 use up to the full 40 Gbps 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 @ 30 Hz true color |
| Mini Display Port | 1.2 | Up to 16 Gbps per lane | Up to 4K2K @ 60 Hz |
| Full-Size Display Port | 1.2 | Up to 16 Gbps per lane | Up to 4K2K @ 60 Hz |
| VGA | |||
| RJ45 | IEEE 802.3 | 10/100/1000 Mb/s | |
| USB (2) | 2.0 Type A | 480 Mbps | 5 V @ 500 mA, 2A Peak |
| USB (2) | 3.0 Type A | 5 Gbps | 5 V @ 900 mA, 2A Peak |
| USB w/Powershare (1) | 3.0 Type A | 5 Gbps | 5 V @ 2A Power Share |
| USB Type-C Thunderbolt™ | Gen 3 | Up to 40 Gbps | Up to 60 W* |
For more information, go to: Thunderbolt 3 Tech Brief
Note: Systems with the two-lane design will only support up to 20gbps data transfers over PCIe devices such as external hard drives or PCIe video cards. Systems with four-lane design will support up to 40gbps of data transfer over PCIe depending on the device in use.
Frequently Asked Questions
What speeds does Thunderbolt support?
Thunderbolt is available in Thunderbolt, Thunderbolt 2, Thunderbolt 3, and Thunderbolt 4.
| Thunderbolt | Thunderbolt 2 | Thunderbolt 3 |
|---|---|---|
| Up to 10 Gbps | Up to 20 Gbps | Up to 40 Gbps |
What types of Thunderbolt devices are available?
Different types of Thunderbolt capable devices available are external hard drives, audio/video capture devices, displays, and I/O hubs.
What type of physical connection does Thunderbolt use?
Thunderbolt uses a connector that fits the mini-DP (DisplayPort) port or connector.
What are the requirements for cables?
Thunderbolt devices require Thunderbolt certified cables for optimal performance. Thunderbolt certified cables come in copper or optical cable variants. Look for the Thunderbolt logo on the connectors and ports.
Although the port's appearance is physically the same as mini-DP (DisplayPort), using standard mini-DP (DisplayPort) cables cannot be used to connect Thunderbolt devices.
How do i find out if my computer, display or cable is Thunderbolt capable?
The port's appearance is physically the same as mini-DP (DisplayPort). To confirm you have a Thunderbolt port on your computer, display, or cable check for the Thunderbolt symbol next to or above the port or connector.
Can I connect USB devices to a Thunderbolt 3 port?
Yes, Thunderbolt 3 uses USB-C port and it is fully compatible with USB devices and cables. However, you may require compatible adapters to connect USB Type-A or other USB connectors.
What is the difference between Thunderbolt 3 and USB-C?
Thunderbolt 3 is a superset solution which includes USB 3.1 (10 Gbps), and adds 40 Gbps Thunderbolt and DisplayPort 1.2 from a single USB-C port.
Affected Products
Alienware 13 R3, Alienware 13 R2, Alienware 15 R3, Alienware 15 R2, Alienware 17 R4, Alienware 17 R3, Inspiron 15 Gaming 7577, Latitude 7280, Latitude 7285 2-in-1, Latitude 7370, Latitude 5480/5488, Latitude 7480, Latitude 5580, Latitude 7275
, Precision 3520, Precision 5520, Precision 7720, Precision 3510, Precision 5510, Precision 7510, Precision 7710, XPS 12 9250, XPS 13 9350 (End of Life), XPS 13 9360, XPS 13 9365 2-in-1, XPS 13 9370, XPS 15 9550, XPS 15 9560
...
Article Properties
Article Number: 000060905
Article Type: Solution
Last Modified: 10 Mar 2025
Version: 6
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