U3818DW, USB hubs functionality?

Good question! Please read through the U3818DW User's Guide. Note, the U3818DW was not tested/validated on the proprietary Apple products. So read through the Apple Forum before purchasing.


To answer your specific USB hub question, the U3818DW User's Guide page states that to use the USB hubs, you must connect the provided USB 3.0 upstream cable to the computer USB port.

Just using the USB Type-C cable may provide enough power to the USB hubs, but you will be limited to USB 2.0 speed. I say may because the USB Type-C bandwidth might be used up just sending the 3840x1600 resolution.

Thanks for the answer. I would be happy with USB 2.0 speed since I only need to connect some low-speed peripherials like mouse and keyboard but according to the manual you provided it looks like I still need to connect second cable to use monitor's USB hub. Thats kinda  disappointing since I only have 2 USB-C ports on the notebook and I need second one for external HDD.

If you use the USB Type C cable, you get the native resolution and can use the 4 USB downstream ports. If you use HDMI or DP you need to connect an additional USB upstream cable. -- There is enough bandwidth.

In fact, I am using it to switch back and forth between my desktop (DP + USB upstream) and notebook (USB Type C) and can can use my mouse, keyboard and usb headset which I have connected to 3 of the displays USB ports.

Thank you this is what I wanted to hear!

There was another MacBook Pro user that only had the USB Type-C cable connected to the U3818DW. He had 3 USB devices connected to the U3818DW USB downstream ports =
hard drive
hard drive
network adapter

All worked, but as soon as the U3818DW went into PSM (PowerSave Mode), the two hard drives and network adapter did not reinitialize. He had to power the U3818DW off, then on to get them to reappear.

Why does this happen, no idea. We are not going to know what Apple driver is used to talk to the U3818DW USB hub. Or why it would not reinitialize those three devices. He never mentioned testing with also the USB 3.0 upstream cable connecting the MacBook Pro to the U3818DW.

The Dell U3818DW is a risk filled adventure for Mac users. There's really only ad hoc community support on the Apple forums. I found on my MBP 2018, when the Dell U3818DW is attached via USB-C, it prevents the MBP from remaining shut down. After 15 seconds, the system reboots.  And during sleep, the Dell awakens every minute to search for a signal and complain that there isn't one. The Dell monitor awakening also causes other attached devices to also wake up every minute. Detaching the Dell monitor results in everything sleeping and shutting down fine. I called Dell support and was told it is impossible for the Dell Monitor to cause this but if a paid support call was available to me (mind you the unit is less than a month old and you'd think a positive Dell experience would be desired). I can't say it was for sure the Dell U3818DW but my initial setup was with a new Mac Pro. But with that system, the display froze 10-20 times a day (system kept running). Fortunately Apple gave me a complete refundfor the Mac Pro. YMMV