Can I connect a 2018 MacBook Pro to a Dell UltraSharp 27 4K Monitor (U2718Q) with a single cable that carries both the display data and the data for the USB ports of the display?

I tried a USB-C to DisplayPort cable, but none of the USB ports of the display would work until I also connected it to the MacBook Pro with a USB cable through one of it's USB upstream ports.

Note that I want to operate the display at full resolution (4K, 3840 x 2160) and a refresh rate of 60 Hz.


2 Answers 2



Technically speaking, you have a Thunderbolt 3 Type C port. "C" is the physical charastic of the port, not the USB specification. Being that it's Thunderbolt 3, its carrying several signals:

  • PCIe
  • USB 3.1
  • DisplayPort
  • Power

Your "end" device is a monitor that has several different inputs

  • HDMI
  • DispayPort (DP)
  • Mini DisplayPort (mdP)
  • USB

When you go from your MacBook's TB 3 port to the video in, you're not passing the USB signal; this is why you need a second cable for the USB functionality. If this was a monitor that accepted Thunderbolt as an input, you could do this with one cable.

  • And can I use my USB-C (Thunderbolt 3) port on my MacBook Pro to pass the video signal to the monitor and at the same time charge my MacBook through thid Dell monitor?
    – vargen_
    Commented Aug 29, 2019 at 8:55
  • @mistercake No, neither DisplayPort nor HDMI can provide power over that connection to charge your laptop. What you need is a dock. The U2718 is a fantastic monitor, I would find a dock/adapter solution over replacing it Commented Dec 5, 2022 at 23:39

Dell UltraSharp 27 4K Monitor (U2718Q) DisplayPort

does not redistribute the input to its USB's.


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