GoKawiilWhy some monitors need a separate USB cable for their hub ports to work
Monitors with built-in USB hubs use two types of ports: an upstream port that links the monitor to a computer, and downstream ports where peripherals like keyboards or drives connect. If a monitor's video signal runs over HDMI or DisplayPort, those cables don't carry USB data, so a separate USB upstream cable is required for the hub's downstream ports to function. USB-C can eliminate that extra cable when the monitor and cable support DisplayPort Alt Mode and USB Power Delivery.
GoKawiil's interpretation of the reporting above, not reported fact.
Many users plug in a monitor's HDMI or DisplayPort cable and then wonder why the attached USB accessories don't work, not realizing a second USB cable is needed for the hub to receive data. Understanding upstream versus downstream ports helps buyers choose the right cables and avoid confusion when setting up multi-device workstations.
- Monitor USB hubs require an upstream connection to the PC and downstream ports for accessories.
- HDMI and DisplayPort cables don't carry the USB data needed to power a monitor's hub ports.
- USB-C can merge video, data and charging into one cable, but only if the device supports the right standards.
Dell UltraSharp U2723QE USB-C Monitor — This monitor is a great example of the USB-C hub setup the article describes, letting a single cable carry video, data, and power between your laptop and peripherals. It has built-in USB-A downstream ports, making it easy to connect a keyboard, mouse, or flash drive right through the display exactly as explained above.
See Dell UltraSharp U2723QE USB-C Monitor on Amazon → Affiliate link — we may earn a commission on purchases, at no extra cost to you. Product picked by AI based on this article; it is not a tested recommendation.Source: engadget.com — Novak Božović, 2026-09-19
Published there as: “Here's why some monitors have two USB ports (and the best ways to use them)”
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