ThinkPad Thunderbolt 3 Dock - No 4k@60hz under MacOs

[hunyeti]

I Just got a new MacBook Pro (2017, Radeon Pro 560), along with a ThinkPad Thunderbolt 3 Dock.

I choose this dock, because i read that it does work with a mac.

But the dock's display outputs are not fully usable under MacOs.
Under Windows 10, everything works as it should, 4K@60hz, or dual (FHD/4K@30hz) monitors, but under MacOs, the best i can get is a single monitor at 4k@30hz. If i plug in another monitor i just get a mirrored image. I'm using display port cables that where previously used with these monitors.

The Display settings sometimes show the 30hz refresh rate, but the dropdown is greyed out, sometimes it doesn't even show up.

The monitor is an LG 27UD58

I tried a few utilities to force a higher refresh rate but non had any effect.
I tried the Thunderbolt unblocker utility, even tho this dock is not blocked, so sadly this had no effect either.
I update the firmware of the dock from windows, it had no effect.

One interesting thing is that under System Information -> Hardware -> Graphics/Displays -> Radeon Pro 560 -> LG Ultra Hd
there is this line:
Connection Type: DVI or HDMI
But i'm clearly using displayport cables.


I'm terribly disappointed because my previous MacBook (2014) could easily drive 2 4k displays at 60hz, with a cheap cable.
For this, apple does not even offer a first party solution for connecting 4k@60hz displays, and it seems 3rd party docks are hit and miss, the apply endorsed Belkin dock have more negative reviews than positive, so i'll probably steer clear of that one as well.

What are my options here?
Can this be solved or returning it is my only choice?
What other docs are worth considering?

(My ideal dock has at least 3 USB3 A ports, ethernet, display port and charging capability)

 

[BeatCrazy]

Have you tried contacting ThinkPad support for the dock? They may have special firmware needed for macOS.

Alternatively, you could use an additional port on the MacBook Pro to feed (via appropriate TB3->HDMI adapter) the monitor directly. Not as clean as a single cable solution, but should be an easy path.

Can you return the dock, and get something from CalDigit? I had good luck with all their docks, including feeding the LG 27UD88 via TB3 and even USB-C @ 4K/60Hz.

 

[hunyeti]

Officially this is a Windows only dock, as Lenovo does not have any mac hardware, and it's meant as an accessory for their laptops. All i could do was to get the latest firmware from their support site.

I'm striving for one cable solution, as i often pick up the laptop.

I'm afraid that CalDigit is not available in my country, and i don't think i can get approval for an international order from my company.

By the way, i just bought an usb-c -> display port cable, (was labeled as DP alt mode), and it does work at 4k@60hz through the dock, while the dock is still providing the single display at 30hz as well.

On windows , it can drive both screens at 60hz.