What is Alt Mode? What type of USB C port does my Windows laptop have?  What about: Drivers and firmware updates What is USB Graphic?

  What is Alt Mode?


Alt Mode   is a term you will come across frequently when investigating USB-C.
Alt Mode is a functional extension of USB-C which enables the USB connection to carry non-USB signals. Alt Mode(s) are optional capabilities that are unique to the USB-C connector or port that allow technologies, like DisplayPort and Thunderbolt 3, to be transmitted. Knowing what devices and ports support the various Alt Modes may be confusing and, at times, frustrating.
DisplayPort over Alt Mode  DisplayPort Alt Mode (DP Alt Mode) allows a USB-C equipped computer to connect directly to a display or monitor. The monitor will need to have a USB-C port for you to make this connection. You can still use a USB-C equipped laptop with monitors that have more traditional video ports, such as VGA, DVI, HDMI, and DisplayPort but you will need to get a USB-C video adapter.
What do I need to know before using DisplayPort over Alt Mode?

  • Confirm your computer’s USB-C port supports DP Alt Mode
  • Read the tech specs on the USB-C video adapter to ensure it supports the resolutions and refresh rates you want
  • If you are interested in a USB-C MST video adapter or laptop docking station, make sure your video card also supports MST
    What to Check: DisplayPort™ over Alt Mode. First things First!
  • Always check the specification of the devices you are going to use. So the Laptop, PC or another source device.
  • Also check the specification of the connecting cables and adapters you are using (also if there Uni- or Bidirectional).
  • Check the specification of the required output device.
  • Make sure they support the USB C over Alt Mode!

How To Check: The USB C Port Version/Type.

What does the USB C port look like?
The USB C port is an oval port. The port is also smaller than a USB A. In addition, the USB C connection is symmetrical. For example, you can insert a USB C plug into a USB C port in 2 ways.

What type of USB C port does my Windows laptop have? 

Next to the ports of a Windows laptop are symbols / logos, which indicate what you can do with the port.

 
 


  • Is there a symbol of a lightning (Thunderbolt 3) next to the USB C port? Then you can charge via this port and pass on a video signal and thus connect a monitor. This port supports DisplayPort alt mode.
  • Is there a symbol of a D (DisplayPort) next to the USB-C port? Then you can pass on a video signal via this port and thus connect a monitor. This port supports DisplayPort alt mode.
  • Is there a symbol of a battery next to the USB C port? Then you can charge your laptop via this port. This port does not support DisplayPort alt mode. 

What about: Drivers and firmware updates

To get the most out of the connection. You may need to do some driver and/or firmware updating. So the best screen resolution and data speed will be available.

  • It is advisable to update the driver or firmware of your device to fix device issues and to take advantage of enhancements that are not available in previous versions.
  • NOTE:   Update and Firmware processes may vary depending on your device’s manufacturer and its operating system (OS) off the device. See their READ-ME files and installation instructions before execution. 
  • IMPORTANT:   Read the user manual of your devices to find out where and how to find the current system/firmware version of your devices


What is USB Graphic?

USB Alternate Mode vs. External Graphics Adapters

Alt Mode:  Native, high-performance, uncompressed video over USB-C ideal for gaming and professional graphics.

External USB Graphics (DisplayLink/Silicon Motion):  Software driven, compressed video over USB ideal for productivity, office, and legacy device setups, but not for high-end gaming or 4K HDR content.

Feature USB Alternate Mode (Alt Mode) External Graphics Units (DisplayLink / Silicon Motion)
How it Works Sends native video signals (DisplayPort, HDMI, or Thunderbolt) directly through the USB-C connector. Encodes video signals via USB using a chip (DisplayLink/Silicon Motion) and software driver; the video is transmitted as compressed data over USB.
GPU Dependence Uses the  internal GPU  of the laptop/PC for rendering. Can offload some tasks to the internal GPU, but often relies heavily on  CPU and compression  for video processing.
Performance High performance, supports  4K @ 60Hz or higher  , low latency, suitable for gaming and professional graphics. Moderate performance, may experience latency and compression artifacts, suitable for office tasks, productivity, and multi-monitor setups but less ideal for gaming or high-end graphics.
Video Quality Native, uncompressed signal ensures  maximum resolution and color fidelity  . Compressed, so slightly lower quality; may show minor artifacts in fast-moving video or detailed graphics.
Compatibility Requires  USB-C port with Alt Mode support  (DisplayPort or Thunderbolt). Works with  any standard USB port  (USB-A or USB-C), often requires driver installation.
Use Cases Gaming laptops, high-end workstations, professional editing, multi-monitor setups with high refresh rates. Office productivity, additional monitors for laptops, docking stations for legacy systems, multi-display workstations where ultimate video performance isn’t critical.
Pros Native quality, low latency, supports HDR, high refresh rates, future-proof. Flexible, works on older laptops without Alt Mode, many monitors supported, cost-effective.
Cons Requires compatible hardware, USB-C port with Alt Mode. Slight latency, compressed video, depends on driver support, limited gaming support.