USB-C Vs. HDMI - Which Display Cable Should You Use?

A modern computer, whether it's a desktop or a laptop, may offer you several port choices when it comes to connecting a display. Depending on your computer, you can have an HDMI port, a regular DisplayPort (DP), or a USB-C port with DP Alt mode, which have replaced the VGA and DVI ports of yesteryears. Each of these ports can help you seamlessly establish a connection to an external display with support for both audio and video signals, and each port has its unique advantages and disadvantages.

While it's relatively uncommon to see all three of the mentioned ports on a single computer, two are pretty common on desktops and even some laptops. So, if your desktop or laptop has both a USB-C port with DP Alt Mode and an HDMI port, which video connection makes more sense to use? Choosing between the two depends significantly on your setup, devices, and what you are trying to achieve.

USB-C is a pretty versatile interface, and besides data transfer and power delivery, it supports video output when it has a DisplayPort Alt Mode configuration. So, if your desktop or laptop has a built-in USB-C port that supports DP Alt Mode or Thunderbolt, you can use it to send video to a display. It's most suitable when you're looking to get a single USB-C cable connection between your laptop and an external display.

If both the laptop and the display support USB Power Delivery (USB PD), you can even send power from the display to the laptop for charging. Besides power and video signals, both devices will also be able to communicate using data, allowing you to attach peripherals and storage devices to the available USB ports on the display and keep your laptop's USB ports free for any other high-bandwidth devices or gadgets. Keep in mind that any storage devices connected to the display may not always get the fastest transfer speeds, as a significant portion of the USB-C connection's bandwidth will go into transferring the video signal. 

Another reason for using a USB-C connection is daisy-chaining multiple monitors. Daisy-chaining is the process of connecting one monitor to the other, rather than connecting both directly to the laptop or desktop CPU. This allows for a cleaner arrangement when passing the display signal in a two-or-more monitor setup. If your laptop's USB-C port supports DP 1.2 or a newer protocol with Multi-Stream Transport (MST), you can daisy-chain multiple displays, provided each monitor also supports DP out with MST.

HDMI ports are pretty common on computers and can come in very handy when you're looking to connect an external display, whether it's a monitor or a TV. It's particularly useful for hooking up a TV or projector to your computer for use as a monitor, as you are unlikely to find USB-C with DP Alt more or DisplayPort on a TV or projector. HDMI is also relatively no-nonsense, as you don't have to worry whether it supports audio or video, unlike USB-C ports, which don't always support DP Alt Mode. So, if you have an HDMI port on your computer and another on your display, all you need is an HDMI cable, and you'll be up and running.

Unfortunately, HDMI doesn't enable a single cable connection, as it can't send power. So, it's most suitable when you have other ways to charge a connected laptop or to power a display (in the case of portable monitors). It also lacks the support for daisy-chaining displays that USB-C has.