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How to Determine Your USB-C Port Video Capabilities

Last Update: March 28th, 2025
Article ID: 3185059

Understanding your laptop's video output capabilities is essential when connecting to external displays. This guide will help you identify what video technologies your laptop supports and how to find the relevant information.

Common Video Output Technologies

Modern laptops commonly use one or more of the following technologies to transmit video to external monitors:

1. Thunderbolt 3

  • Supports video output using the DisplayPort protocol.
  • Capable of driving up to two 4K displays at 60Hz or one 5K display at 60Hz.
  • Uses a USB-C connector and features a lightning bolt symbol next to the port.

Note: An example of Thunderbolt 3 ports

2. Thunderbolt 4

  • Provides improved performance over Thunderbolt 3.
  • Supports up to two 4K displays at 60Hz or one 8K display.
  • Uses a USB-C connector with the same lightning bolt symbol but may also include the number "4" for identification.

Note: Thunderbolt 4 has the same physical connection and “lightning” bolt icon as Thunderbolt 3

3. USB-C DisplayPort "Alt Mode"

  • Allows video output directly through the USB-C port using DisplayPort technology.
  • Commonly supports one 4K display at 60Hz, but capabilities may vary.
  • Often marked with a DisplayPort ("DP") symbol, but this feature may also be specified in your system's documentation.

Note: An example of a USB-C port with DisplayPort capabilities

How to Identify Your Laptop's Video Capabilities

To determine what video technologies your laptop supports, follow these steps:

1. Check Your Laptop's User Manual:

  • Locate your laptop's user manual (often available online from the manufacturer's support site).
  • Search for keywords like "Thunderbolt," "DisplayPort Alt Mode," or "video output capabilities."

2. Visit the Manufacturer's Website:

  • Go to the support page for your laptop model and find the technical specifications section.
  • Look for details on Thunderbolt or USB-C video capabilities.

3. Inspect Your Laptop's Ports:

  • Check for identifying symbols next to USB-C ports:
    • Thunderbolt 3/4 ports may have a lightning bolt symbol.
    • DisplayPort Alt Mode may be marked with a "DP" icon.

“What if I do not have the above technologies?”: USB 3.0 (Type-A) and Display Expansion

While USB 3.0 (Type-A) ports do not support native video output, they can still be used to extend to two or more displays using software-based solutions like DisplayLink or Silicon Motion's InstantView. These technologies enable video through USB-A ports by utilizing dedicated drivers and software.

If your laptop lacks Thunderbolt or USB-C video capabilities, DisplayLink or InstantView may be a viable alternative for expanding your display setup. A few other things to consider:

  • Not all USB-C ports support video output. Checking your laptop's documentation is crucial to confirm this capability.
  • Thunderbolt ports are backward compatible with USB-C DisplayPort Alt Mode but provide enhanced performance and flexibility.

If you have further questions about connecting your Plugable docking station or adapter to your laptop, please reach out to our support team for guidance.