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Is there a hub which can drive 2 screens directly without relying on DisplayPort-MST and charge a laptop at 85W?

What I'm trying to find is a hub which would allow the following using only 1 cable to the laptop (thunderbolt preferably or USB type C):

  • charge a 15" MacBook Pro (85W) at full speed
  • use 2 external monitors over HDMI or display port in extended mode
  • keep using the macbook's screen (effectively driving 3 screens in extended mode)

All of this from Mac OS.

I have tried multiple docks so far, and none seems to offer a simple way of connecting multiple monitors to the MacBook 15" (2018).

The USB ones I tried require a display link driver. Despite this they don't drive more than 1 monitor (1080p) at a time. If you connect 2 they copy the same image to both monitors (so they work but not in extended mode)

Another issue with the thunderbolt 3 ones is that all the ones I looked at are unable to drive 2 screens over DP or HDMI directly. They require either:

  • one of the screens to be connected using thunderbolt or USB-C
  • the OS of the computer attached must handle DisplayPort-MST

The issue is that OSX does not support DisplayPort-MST for hubs https://en.wikipedia.org/wiki/DisplayPort#Multi-Stream_Transport_(MST) (even if apple mentions MST support in their docs)

A solution which seems to work with most setups is to add a USC-C to HDMI dongle. But this comes at the expense of having to use another dongle, and of sacrificing daisy chaining.

I have found that using a thunderbolt 3 hub and connecting it to a second hub (thunderbolt 2 or 3 consistently and USB-C sometimes) allows me to drive 2 monitors in extended mode without sacrificing chaining, even when the MacBook is using the built-in display, but this is not the ideal solution as it requires multiple docks per computer.

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    There's at least 3 distinct questions here... 1) a single cable solution 2) driving multiple monitors with/without DisplayLink drivers, and 3) keeping the built in monitor on. Please rework the question to a single topic. As it is, it's very difficult to understand what the actual issue is. – Allan Oct 2 '18 at 13:50
  • @Allan I'm looking for a solution to drive 2 external screens while the MacBook screen is on (there are solutions with will drive 2 external screens only if the MacBook is closed and its screen is disabled) and charge my MacBook 15" at the same time. All this using only one thunderbolt or usb-c cable (thence the 1 cable solution) – Coyote Oct 4 '18 at 21:48
  • @bmike I updated the question with more detail. – Coyote Oct 4 '18 at 22:12
  • StarTech makes a dock that fits your requirements, but I haven't tested it. Which docks have you tried? – Allan Oct 5 '18 at 11:50
  • @Allan I have tried hubs from Kensington, CallDigit, Lenovo, Belkin, and one from some other brand I can't remember which did not provide what I'm looking for. – Coyote Oct 6 '18 at 19:14
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You need a Thunderbolt 3 dock - many exist. What you seem to be confused about is that they require a Thunderbolt 3 monitor - they don't. You can buy a simply cable to connect the Thunderbolt 3 port on the dock to the monitor via DisplayPort or mini-DisplayPort.

I'm using the OWC 12-port Thunderbolt 3 dock for attaching dual-monitors to the MacBook Pro while charging it at the same time. Monitors are both connected using mini-DisplayPort. This does not use MST as that is not supported by macOS. Nor does it use DisplayLink. It is all connected to the MacBook Pro with a single Thunderbolt 3 cable.

You can also use other Thunderbolt 3 docks such as the OWC 14-port Thunderbolt 3 dock, the Belkin Thunderbolt 3 Express Dock HD, the Caldigit TS3, the Elgato Thunderbolt 3 Pro Dock, and many others. They all provide 85 watts for charging and allow attaching two monitors.

It would seem that the docks you have tested earlier are USB-C docks. They require MST to be able to support dual-displays, or they use DisplayLink. MST is not supported on macOS, so that's only going to work if you run Windows on the MacBook Pro. DisplayLink is generally limited in performance compared to a native DisplayPort signal.

  • Are you saying you effectively block the 2nd thunderbolt port using a dongle? Which would in effect be equivalent to: A solution which seems to work with most setups is to add a USC-C to HDMI dongle., wouldn't it? – Coyote May 2 at 17:36
  • After re-reading my question I realised it is pretty badly phrased despite a few edits. – Coyote May 2 at 17:41
  • There are no dongles involved. The Thunderbolt 3 port natively contains a DisplayPort signal. You can buy a simple, passive cable without any electronics that will connect from the Thunderbolt 3 port on the dock to the DisplayPort or mini-DisplayPort on a monitor. This means that you can have a single cable attached to the laptop which provides charging as well as connecting two 4K monitors (and potentially USB devices, Ethernet, etc.) – jksoegaard May 2 at 22:06

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