Summary
The number of external monitors you can connect to a computer depends on its graphics hardware, operating system, and the technology used to connect the displays.
Most computers have a limit on the number of monitors they can support directly through their built-in video outputs. However, Plugable docking stations and USB graphics adapters that use DisplayLink or Silicon Motion technology can allow you to connect additional monitors through USB, beyond the computer's native display limitations.
Depending on the operating system, display resolution, and computer specifications, up to eight additional displays may be supported using compatible USB graphics products.
These additional displays can generally operate alongside monitors connected directly to the computer's native video outputs.
Applicable To
- Plugable DisplayLink-based docking stations and USB graphics adapters
- Plugable Silicon Motion-based USB graphics adapters
- Compatible Windows, macOS, and ChromeOS computers
- Users looking to expand their workspace beyond their computer's native external display limitations
How Does USB Graphics Technology Add More Displays?
Most computers have a maximum number of external displays they can support natively. This limitation is primarily determined by the computer's graphics processing unit (GPU), operating system, and available video connections.
DisplayLink and Silicon Motion use an approach commonly referred to as indirect display technology.
Instead of requiring each monitor to connect directly to a native graphics output, these technologies use software and the computer's processing resources to generate display information and transmit it over USB to a compatible docking station or graphics adapter.
This allows additional monitors to be connected without relying entirely on the computer's native display output capabilities.
However, indirect display technology still depends on the computer's CPU, GPU, USB connection, and operating system. Adding more displays increases the resources required to operate them.
Maximum Number of USB Graphics Displays Supported by Plugable
The following table outlines Plugable's general supported display limits for DisplayLink and Silicon Motion technologies across different operating systems.
| USB Graphics Technology | Windows | macOS | ChromeOS |
|---|---|---|---|
| DisplayLink | Up to 8 at 1920 × 1080 or 4 at 3840 × 2160 | Up to 4 at 3840 × 2160¹ | Up to 8 at 1920 × 1080 or 4 at 3840 × 2160² |
| Silicon Motion | Up to 8 at 1920 × 1080 or 4 at 3840 × 2160 | Up to 4 at 3840 × 2160 | Up to 8 at 1920 × 1080 or 4 at 3840 × 2160² |
Important Notes:
- These values represent general supported configurations, not a guarantee that every computer or Plugable product can operate the maximum number of displays.
- The number of monitors supported by an individual docking station or graphics adapter depends on that product's specifications.
- ¹ On macOS, displays added through Apple's Sidecar feature may count toward the supported indirect display total. For more information, see Apple's Sidecar documentation.
- ² ChromeOS display performance depends on the computer's hardware. Chromebooks with lower-performance CPUs or GPUs may support fewer displays.
- These limits apply to indirect USB graphics displays. Additional natively connected monitors may be supported, depending on the computer's specifications.
For multi-monitor setups approaching these limits, we recommend contacting Plugable Support to verify compatibility before purchasing additional adapters.
Performance and Technical Limitations
Although USB graphics technology can expand the number of displays connected to a computer, several factors determine how many monitors can operate reliably.
Host Computer CPU and GPU Resources
DisplayLink and Silicon Motion graphics solutions rely on the host computer's CPU and GPU resources to process the content displayed on connected monitors.
As additional USB graphics displays are connected, more system resources are required.
The amount of processing power needed depends on the content being displayed.
For example:
- Static content: Spreadsheets, documents, email, and other office applications generally require fewer resources.
- Dynamic content: Video playback, animations, and rapidly changing content require additional processing and USB bandwidth.
- Graphics-intensive applications: Gaming, 3D rendering, and other demanding graphical workloads may experience reduced performance and are generally not recommended for indirect USB graphics displays.
A computer that can comfortably support several monitors displaying office applications may not deliver the same performance when running demanding content across every display.
USB Connection and Device Limitations
USB graphics adapters communicate with the computer through its USB subsystem.
Although USB supports multiple connected devices, practical limitations can affect how many USB graphics adapters and other peripherals can operate simultaneously.
These limitations depend on several factors:
- The computer's USB controller and available system resources
- The number of connected USB devices and hubs
- The USB connection speed and available bandwidth
- The capabilities of the individual docking stations or graphics adapters
As additional USB devices are connected, some systems may encounter bandwidth limitations, reduced performance, or issues recognizing connected devices.
Using USB 3.0 or faster connections, when supported by the product, is recommended for the best experience with multiple USB graphics displays.
Operating System and Software Requirements
DisplayLink and Silicon Motion products require compatible software support to function properly.
- Windows: Compatible USB graphics products require the appropriate DisplayLink or Silicon Motion software. Some drivers may be installed automatically through Windows Update.
- macOS: DisplayLink and Silicon Motion products require their respective software, along with any necessary macOS permissions.
- ChromeOS: Compatible USB graphics products may operate using built-in operating system support, depending on the product and ChromeOS version.
Before connecting multiple monitors, confirm that your Plugable products support your operating system and that any required software is installed and configured correctly.
Important Notes
- USB graphics and native video connections are different. DisplayLink and Silicon Motion allow additional monitors to operate through USB, while native HDMI, DisplayPort, USB-C DisplayPort Alt Mode, and Thunderbolt video connections remain subject to the computer's native graphics capabilities.
- The maximum number of monitors is not guaranteed. Actual results depend on the computer's hardware, operating system, available USB resources, and connected display configuration.
- Higher resolutions require additional resources. A setup using several 4K monitors generally places greater demands on the system than an equivalent setup using 1080p monitors.
- Not every Plugable dock supports the same number of monitors. Always check the specifications of your particular docking station or USB graphics adapter.
- USB graphics technology is best suited for productivity applications. For gaming or other graphics-intensive workloads, a monitor connected directly to the computer's native graphics output is generally recommended.
- Multiple USB graphics technologies require careful compatibility planning. When combining DisplayLink, Silicon Motion, and native graphics connections, supported display counts and performance should be verified for the specific system.
Need Assistance?
If you're planning a multi-monitor setup and aren't sure how many displays your computer can support, please contact Plugable Support at support@plugable.com.
When contacting support, please include:
- Your computer manufacturer and model
- Your operating system and version
- The Plugable docking station or USB graphics adapter model(s) you're using or considering
- The number of external monitors you want to connect
- The resolution and refresh rate of each monitor
- How you plan to connect the monitors to your computer
This information will help our support team evaluate your system's capabilities and recommend an appropriate configuration for your multi-monitor setup.
