No. Most DisplayPort to HDMI cables and adapters are one-way adapters from a DisplayPort Source (computer or docking station) to a HDMI Sink (television, computer monitor, or projector).  These cables do not work in reverse.

DisplayPort uses packet-based data transmission, breaking the video stream into individual packets of data allows for longer cable runs, use in both copper and fiber-optic cables, and allows for higher bandwidth than other video formats.  It is relatively easy to convert from DisplayPort to HDMI (computers with HDMI output ports already do this internally) and dual-mode DisplayPort outputs have built-in adapters to  output a HDMI signal for use with passive DisplayPort to HDMI adapters.

HDMI uses a video signal, similar to DVI, this requires more power to operate at the same cable lengths as DisplayPort and requires significantly more processing power to create DisplayPort packet-based data.

Externally powered HDMI to DisplayPort adapters do exist, these generally have a USB or small barrel plug for power, and can convert from a HDMI Source to DisplayPort Sink.  In most cases they have reduced resolution or refresh rates compared to modern signal sources and can introduce delay in the data connection between the display and computer potentially causing reduced connectivity or display performance problems.

We do not currently recommend using HDMI to DisplayPort adapter with our docking stations.  In our testing they have been unreliable compared to a native DisplayPort connection.  Many of our  newer docking stations include both HDMI and DisplayPort outputs to reduce the need for additional adapters or adapter cables.

Most Windows notebook computers power management settings will default to putting the computer to sleep with the lid closed, regardless of any external displays, keyboard, or mouse connected to the computer. If this is happening but you would prefer the system to remain active with the lid closed utilizing the external display or displays, these settings can be changed by performing the following:

For Windows 10:

1. Start by right-clicking on the Start button and select Power Options from the menu.
2. From the right side of the Power Options settings page, select the blue link for Additional power settings

   

3. From the choices present on the left-hand side of the Power Options window, please click on Choose what closing the lid does
4. Make sure the setting for When I close the lid under the Plugged In column is set to Do Nothing

   

5. Click the Save Changes button and restart the system (making sure that the laptop’s power adapter is also connected) and test the behavior again.

For Windows 11:

1. Start by right-clicking on the Start button and select Power Options from the menu.

   

2. In the upper left corner of the settings window, in the search box, type "lid" then select Change what closing the lid does from the search results

   

3. Make sure the setting for When I close the lid under the Plugged In column is set to Do Nothing

   

4. Click the Save Changes button to apply the new settings.

Closing the lid should no longer put the computer into sleep mode when an external display and power source is connected, instead one of the external displays should now become the Primary display with the desktop icons instead of the laptop's built-in display.

The lid may still need to be opened to perform the following tasks:

• To power on the computer from a fully powered off state
• To log into the computer if logged out or if the computer is restarted with the lid closed
• To wake the computer from a deep sleep state ( hibernation, or Windows hybrid sleep states )

Unfortunately Plugable products do not support the Apple SuperDrive.

The Apple SuperDrive has stringent power requirements that can only be met by directly connecting the SuperDrive to your host laptop. As a result at this time Apple recommends only using their USB-C adapter cables. You can find more information on that here → How to connect the Apple USB SuperDrive

If you have purchased a Plugable product to use with your Apple SuperDrive, and would like some additional assistance please do not hesitate to reach out. You can do so by emailing support@plugable.com, or going to Plugable.com/Support.

We are often asked if it is okay to leave a notebook computer connected to one of our USB-C docking stations with Power Delivery for extended periods of time.  The short answer is yes, it is no different from leaving the laptop connected to the manufacturer's original USB-C power supply for the same time.  The long answer is yes for modern laptops, and maybe for older (1990s-early 2000s laptops) and involves going into the different battery technologies used in consumer electronics devices.

Another common question is if it is possible to use the docking station but to disable powering and charging the computer.  When a modern notebook computer runs on battery power it will often set the system to a reduced power state which may impact performance, or connected devices and we recommend always powering the computer when using a desktop docking station.  For all of our docking stations that provide power to the host computer this will not affect the lifespan of the computer's battery.

Modern Laptop Batteries: Lithium-Ion

Lithium-ion (li-ion) batteries are found in a wide range of consumer electronics from notebook computers and cell phones, to electric cars, power tools, and wearable electronics like wireless earbuds.  Li-ion offers fast charging, high-current discharging, fairly long service live compared to other rechargeable battery technologies and are relatively inexpensive.

The life-span of a rechargeable battery depends on many factors including age, temperature history, charging patterns, the chemical composition of the specific battery, and usage.  For example batteries stored at 100% charge will degrade faster than batteries stored at 50% charge, this is why most consumer electronics devices arrive from the manufacturer with between 25% to 75% charge.

Lithium-ion batteries are consumable components, however in most modern computers, cell phones, and tablets these are not user serviceable components.  To help maintain the battery all modern computers and most consumer electronics will include battery charge and protection circuits.  These can be fairly simple, charging up the battery at preset rates depending on the charge level to help maintain the battery life, or complex software controlled charging that monitors battery temperature, voltage and current draw to maintain the fastest charging while maintaining the battery longevity.

Modern notebook computers can be left connected to the original power cable or a docking station with charging capability for extended periods, and do not benefit from regular discharge/recharge cycles.  Our docking stations with charging capability rely on USB Type-C Power Delivery to power and charge compatible computers.  USB Type-C Power Delivery is a negotiated charging protocol between the host computer and the docking station or USB Type-C power supply, this allows the computer to draw only the power it requires, and even select the best voltage level for powering the computer.  In combination with a computer's built-in battery charging controller the computer is capable of maintaining the battery's optimal state even when left connected to a power source for an extended period of time.

Legacy Laptop Batteries: NiCad and NiMH

Older laptops, from the 1990s and some early 2000s, as well as some consumer electronics, and most rechargeable AA or AAA battery replacements use Nickel-Cadmium (NiCad) or Nickel-Metal Hydride (NiMH) batteries.  These batteries are slower to charge and discharge than li-ion batteries, and require very simple charge controllers, and in some cases can even be trickle-charged ( very low-current continuous charging ) if desired.

These batteries generally don't have smart charging controllers and to prolong the life of the battery required "training" or fully discharging and recharging the battery every so often.  Many laptop manufacturers recommended fully charging and discharging a new laptop 2-3 times to train the battery, this is not necessary with modern laptops.

Conclusion

Modern notebook batteries are managed by the computer's built-in battery charging circuit, and require little to no user intervention to maintain optimal battery health.  It does not harm the battery to leave the computer connected to an external power supply, so long as the computer is being used regularly.  If the computer is to be stored for a prolonged period then discharging the battery to between 50-75% can help to maintain the battery life.

Batteries are consumable components and degrade over time, however modern notebook computers can extend the battery life generally to meet or exceed the life of the computer's other electronic components.

It's not uncommon for users to notice a certain level of heat generation from electronics and by extension, Plugable products during operation. In this knowledge base article, we'll explore the reasons behind this heat generation and why it is considered a normal experience within reasonable limits.

Electronics, by their nature, generate heat during operation. This is primarily a result of the electrical current flowing through various components, such as integrated circuits, transistors, and other electronic elements. As Plugable products are designed to efficiently process and transfer data (among other functionality), some level of heat generation is inherent.

Factors Influencing Heat Generation:

1. Power Consumption: The power consumption of a device directly influences the amount of heat it generates. Higher power usage, especially during data transfer or charging processes, can lead to increased heat.
2. Enclosure Design: The design of the product's enclosure and its ability to dissipate heat play a crucial role. Adequate ventilation and heat sinks are often incorporated to manage and disperse generated heat effectively. This is evident in our TBT3-UDZ and TBT4-UDZ designs. The metal case in these docks are designed to function as a heatsink with thermal pads placed throughout the enclosure. This allows heat dissipation from inside to the outside, but will also make it feel as if the device is “too hot”. 
3. Ambient Temperature: The external environment may also play a role. Higher ambient temperatures can contribute to increased perceived heat from the product. This means that summer temperatures may increase the heat generation of not just Plugable products, but many other electronic devices.

Normal Heat Levels: While it is normal for electronic devices to generate heat, Plugable products are engineered to operate within safe temperature ranges. We conduct rigorous testing to ensure that the heat generated during normal operation falls within industry-standard safety parameters. While not all products are or need to be UL certified, we try to go by UL guidelines for thermal readings. The UL threshold is 77C/170.6F, and we aim for around 71C/160F.

Tips for Users:

1. Ventilation: Ensure that Plugable products have sufficient ventilation around them. Avoid placing them in enclosed spaces where heat dissipation may be impeded.
2. Usage Patterns: Intensive tasks such as high-speed data transfer or charging multiple devices simultaneously may result in increased heat generation. This is generally normal but may be more noticeable in such scenarios.
3. Accessories: A number of our devices will allow for the connection of USB accessories and as such, these will require power. If too many “power-hungry” devices are connected, this will cause the device to run much hotter than expected. Be sure to keep in mind the power limits of your dock/device.

In conclusion, experiencing heat from Plugable products is a normal aspect of their operation. Users can rest assured that we prioritize the safety and efficiency of our devices. By understanding the factors influencing heat generation and following simple usage guidelines, users can make the most of their Plugable products while ensuring a reliable and efficient user experience.

What is Alt Mode, and how does it work?

USB-C is a truly versatile connection that supports a range of functions, including power delivery, data transfer, and video. Alt Mode leverages this versatility by repurposing high-speed data pins to enable alternative video data protocols. Many of our docking stations support this protocol, but there is a catch! To take advantage of this feature, your host system must support Alt Mode via the host USB-C port and controller. If the host system and device support Alt Mode, the USB-C ports automatically switch from its default data protocol to the required Alt Mode protocol for video. 

How do I determine if my system supports Alt Mode?

Reviewing your manufacturer's system specifications or user manual is the easiest way to determine if your system supports Alt Mode via the USB-C port, but unfortunately, it’s not always consistent or straightforward. Below, we have included examples of how some system manufacturers mention the capabilities of the USB-C ports on their laptops. This information will usually be included in the user manuals or system specification sheets.

Please note that mention of DisplayPort or DP 1.2, 1,4, and 2.1 indicates Alt Mode support.

Lenovo

HP

Dell

Additionally, some manufacturers, but not all, will also include a DP symbol next to the port to illustrate its ability to support video. If your USB-C port is unmarked, check your user manual or consult the system specifications. 

What about Thunderbolt 4 and USB4?

Unlike earlier iterations of USB-C, which use Alt Mode for video support, USB4 and Thunderbolt 4 primarily use video tunnelling to transmit video over the USB-C connection. Video tunnelling dynamically allocates bandwidth for video and data to ensure optimized performance. If a device does not fully support video tunnelling, your Thunderbolt 4 or USB4-capable system can fall back to Alt Mode, ensuring compatibility with devices that support Alt Mode for video. So you don’t have to worry about a Thunderbolt or USB4 connection supporting USB-C Alt Mode!

Troubleshooting For Alt Mode 

When using a USB-C video cable, adapter, docking station, or hub, it's important to ensure that your laptop supports Alt Mode. If you encounter any issues, the following steps can help you troubleshoot and determine why video may not be working through your USB-C Alt Mode cable or device.

1. First and foremost, check to ensure that your system supports Alt Mode. This is vital as Alt Mode is an optional feature that not all manufacturers include on their systems.
   1. If your system does not support Alt Mode, unfortunately, this is a hardware limitation, and there is no workaround for achieving Alt Mode compatibility. However, it’s possible to still drive external monitors through DisplayLink.
2. Reboot your system and perform a power reset on your docking station or hub (if applicable)
3. If you are using a docking station, ensure that you are using a USB-C cable that supports Alt Mode. 
   1. Not all cables are created equal—USB-C cables that support USB 2.0 only or “charging only” cables are not built to support video. To ensure compatibility, all of our Alt Mode-capable products will come with a USB-C cable that supports this feature.
   2. Do not use USB-C to USB-A adapters, as they are not designed to support video transmission.
4. Be sure to check your operating system's display settings. The connected display can sometimes be disabled within the display settings, or the resolution and refresh may need to be adjusted to match what your device or display can support.
5. Check if your Alt Mode-capable device has any firmware updates listed specifically for Alt Mode.
6. Ensure that your system is up to date with all its latest drivers, firmware, and BIOS, especially your USB and internal graphics controller. Outdated drivers can often lead to connectivity issues, and at times, a BIOS update is needed, which the system manufacturer will generally mention on their official support page.
7. Check BIOS and UEFI settings; some manufacturers add settings that control USB-C functionality. Ensure that your settings are enabled and correctly configured for Alt Mode.
8. Test out another USB-C port on your system if you have more than one. This is beneficial in determining if the issues are related to the specific port.

Benefits of USB-C Alt Mode

Alt Mode over USB-C provides a direct connection to the GPU, allowing you to take advantage of the capabilities of your built-in GPU. This ensures native-level performance without the need for extra software or drivers. As a result, your USB-C Alt Mode-connected display will have reduced latency compared to other methods of adding additional displays, making it perfect for users who require sharp and detailed visuals at optimal refresh rates. Unlike traditional video connectors like HDMI or DisplayPort, which only support video, a USB-C connection with Alt Mode is more flexible and multifunctional, allowing a single connection to carry video, data, and power delivery.

Alt Mode supported devices from Plugable

If your system supports Alt Mode or if you are looking to get more out of your laptop, especially Apple M1, M2, or M3 base chipsets (which are limited to one external display), we have compiled some options below that utilize Alt Mode or a combination of Alt Mode and DisplayLink for even more monitor expandability.

Plugable USB-C Docking Station with HDMI, 60W Laptop Charging
SKU: UD-CA1A

The UD-CA1A is a versatile docking station that enables you to connect a 4K HDMI display via Alt Mode. In addition, it comes equipped with high-speed Gigabit Ethernet, USB 3.0 ports, 3.5mm jacks for headphones and microphone, and will provide 60W of power delivery to your host device—all via a single USB-C port. It is compatible with macOS, Windows, ChromeOS, Linux, iOS, and iPadOS, making it the ideal solution for any setup. You can enjoy seamless plug-and-play functionality and save space with its sleek vertical design or lay it flat for a more subtle look.  

Plugable USB-C 7-in-1 Hub with Ethernet
SKU: USBC-7IN1E  

The USBC-7IN1E instantly transforms a single USB-C with Alt Mode or Thunderbolt port into a versatile hub featuring 2x USB 3.0 ports, a 4K HDMI output, Gigabit Ethernet, and SD and microSD card readers. For hosts that support Power Delivery over USB-C, this hub also supports 100W PD passthrough, allowing you to plug in your included USB-C power adapter to further simplify your setup for greater portable productivity.

The products mentioned above demonstrate the versatility of a single USB-C connection. Plugable offers a wide range of solutions to meet your needs. Whether you are looking for a full-featured docking station that utilizes DisplayLink and USB-C Alt mode, such as our UD-ULTC4K, or a USB-C cable that supports video, data, and charging, like our USBC-240W-1M, you can rest assured that we have you covered. If you have any questions or need help building a solution that takes full advantage of your laptop's USB-C connection, please reach out to us at support@plugable.com.

Overview

With the release of Apple’s M3 CPU chips and the Sonoma 14.6 update your base MacBook Air and MacBook Pro systems with M3 chips can now host two external displays natively in clamshell mode. This guide will walk you through the process of setting up and using two external displays with the lid closed on your MacBook Air or MacBook Pro equipped with an Apple M3 chip.

Requirements

Before getting started, ensure you have the following:

• MacBook Air or MacBook Pro with an Apple M3 chip.
• macOS Sonoma 14.3 or later for an M3 MacBook Air or macOS Sonoma 14.6 or later for an M3 MacBook Pro.
• Two external displays with compatible video inputs (e.g., HDMI, DisplayPort, USB-C).
  • A dock or graphics adapter can be used as well.
• External keyboard and mouse (wired or wireless).
• Power adapter or power source for your MacBook
  • A docking station that provides adequate charge can be used in place of the native power adapter, be sure to check the wattage your dock provides.

Steps to Set Up Dual External Displays with the Lid Closed

1. Set Up Your External Keyboard and Mouse

• If you’re using a wired keyboard and mouse, connect them directly to your MacBook or Plugable dock.
• For wireless peripherals, ensure they are paired with your MacBook and functioning properly.
• An AC adapter/power cable of some kind will also need to be connected for clamshell mode to function properly. This adapter can be one from a docking station or the included Apple adapter.

2. Connect Your Displays

• Connect the first external display to your MacBook using the appropriate cable (e.g., HDMI, DisplayPort, USB-C)
• Close your laptop’s lid.
• Connect the second external display using a similar method.
• Ensure both displays are powered on and set to the correct input source.

3. Configure Display Settings

• Open System Settings on your MacBook.
• Go to Displays.
• You should see both external displays listed. Arrange them according to your preference by dragging the display icons.
• Adjust the resolution, refresh rate, and other settings as needed.

4. Enable "Clamshell Mode" (Lid Closed Mode)

• With your external displays connected and set up, close the lid of your MacBook.
• Your MacBook will automatically switch to "Clamshell Mode," where the internal display turns off, and the external displays become your primary screens.
• Ensure your MacBook is connected to a power source to prevent it from entering sleep mode.

5. Check the Display Arrangement

• With the lid closed, check that the external displays are functioning as expected.
• If necessary, re-open the Displays settings to adjust the arrangement, resolution, or other preferences.

Troubleshooting Tips

• No Display on External Monitors: If the external displays are not showing anything, open the lid of your MacBook and check the connections.
• MacBook Sleeps When Lid Is Closed: Make sure your MacBook is connected to a power adapter. Clamshell Mode requires the MacBook to be plugged into an external power source.
• Performance Issues: If you experience lag or performance drops, try lowering the resolution or refresh rate of the external displays.

Thunderbolt Dock Users

With these steps, one can use Plugable Thunderbolt docks to enjoy a dual-display setup without the need for additional software installation. The dock leverages the native capabilities of the MacBook Air M3 and MacBook Pro M3, providing a straightforward and efficient solution for expanding your workspace with additional USB ports, audio, and ethernet (as well as the dual displays).

Additional Resources

If you should need any assistance with your setup, please feel free to reach out to our support team at support@plugable.com.

Most modern laptops that support USB-C DisplayPort 1.2 Alt Mode should Support two displays.

You may have to research some technical specifications for your laptop to see exactly what version of DisplayPort your computer supports.

• DisplayPort 1.2 should allow for two 1080p@60Hz displays to be connected.
• DisplayPort 1.4 should allow for two 4K@60Hz displays to be connected.
• DisplayPort 1.4 with DSC 1.2 support should allow you to connect 8K@60Hz displays.

Display Stream Compression (DSC) 1.2 enables visually lossless compression for ultra-high-definition (UHD) displays, while also supporting High Dynamic Range (HDR).

If you're unsure or can't find the appropriate technical specifications for the version of DisplayPort your computer supports, you may want to contact the computer manufacturer support team for more detailed information.