He is an ‘IT lover’ who answers questions about IT in general or questions from readers who have concerns about product and service selection. This time, this is an inquiry from a person who wants to connect two monitors to a laptop and use it as a total of three screens. It looks like you tried to decorate a 3-screen environment with a multi-hub for the Type-C port, but it doesn’t seem to work out for some reason. The story you sent is as follows (some content redacted).
Hello. I’m trying to configure a triple monitor configuration by attaching two monitors to a laptop using multi-hub, but it didn’t work out. The screen comes out fine on the monitor connected to the HDMI attached to the laptop, but the screen does not come out on the monitor connected to the HDMI of the multi-hub. I bought a multicenter and returned it, how can I solve the problem?
The HDMI function of the multi-center may not be available depending on the system.
Hello. Thank you for your interest in our article. It seems that you have bought a multi-hub for Type-C ports, which is popular recently. It is very convenient because you can expand to various ports by connecting a single cable to the Type-C port. In particular, some of these products have HDMI ports, so many people like you who want to connect additional monitors buy them.
Multi-hub for Type-C ports recently released in the market (Source = Belkin)However, there is something to be aware of. In the case of the Type-C port on some PCs, it does not support the function of outputting video through the HDMI of the multi-hub. Even Type-C ports that look identical may have different internal specifications.
To output video via HDMI from the multi-hub, the connected system’s Type-C port must support ‘DP ALT (DisplayPort Alternate)’ mode. As the name suggests, this means it is a Type-C port capable of outputting DisplayPort signals. Type-C ports that do not support DP ALT mode only transmit general data signals, so even if you connect a multi-hub, the USB or wired LAN ports on it work, but not HDMI works.
Type-C port that can output screen, how to distinguish?
Therefore, if you want to extend your monitor using multi-center, you must check if the Type-C port on your system supports DP ALT mode. These Type-C ports have the DP logo stamped around the port.
Example of a Type-C port supporting ALT DP mode (Source = IT Donga)And among the Type-C ports, there is also a lightning-shaped logo, called the Thunderbolt port. It is a high-performance interface that supports DP ALT mode as well as a data transfer speed faster than USB.
A standard Thunderbolt 3 port that supports high-speed data transfer and screen output (Source = IT Donga)However, in the case of some laptops or desktops, the function of the port can be displayed without a logo or with its own logo. And some products have DP ALT mode support / unsupported Type-C port in parallel. If it’s hard to tell, it’s best to contact the laptop manufacturer directly.
If it’s a simple screen extension, you can use an external USB graphics card.
Judging from the questioner’s query, it seems that your laptop’s Type-C port does not support DP ALT mode. In this case, it is recommended to extend the monitor via a USB-type external graphics card rather than a Type-C multi-hub. The price is about tens of thousands of dollars.
USB external graphics cards are also sold under names such as ‘USB to HDMI converter adapter’, which, as the name suggests, is a type of graphics output device that is placed outside the system. via a USB port. Regardless of whether technology such as DP ALT or Thunderbolt mode is supported or not, video output is possible by connecting to a common USB 3.0 port that most PCs have, so you can easily expand your monitor. Depending on the product, in addition to HDMI, DVI or VGA (D-Sub) output ports are also available, so you can buy one that suits your monitor. It is theoretically possible to buy multiple units and expand to more than 4 or 5 monitors.
USB external graphics card compatible with most systems (Source = Lenovo)FYI, if you connect an external USB graphics card to the system, the operating system recognizes that another graphics card has been added. Depending on the product, you may need to install a device driver on the initial connection.
However, since the external USB graphics card has a limitation in the bandwidth (path through which data passes) of the USB 3.0 interface, its performance is slightly lower than that of the graphics card inside the PC. The screen resolution is also supported only up to full HD level (1920×1080). Refer to the product purchase!
‘IT Affectionate Man’ aims to provide direct assistance to readers who are concerned about the process of choosing or using IT products or services. We intend to share our knowledge with all readers by providing customized consultations with ‘love’ in any field such as PCs, smartphones, cameras, AV devices, accessories and applications. If you would like to help, please email pengo@itdonga.com. If the story is accepted, we will give you a reply.
Donga.com professional IT reporter Youngwoo Kim pengo@itdonga.com
