Macbook 2015 12inch Retina with USB-C

[Carlo]

Originally Posted by wahlfeld

If I'm getting the same outcome regardless of the dock (and cable) or the USB-C/A adapter, and the docks are working consistently with non-Macbooks, then surely that must mean it's software related or specifically my Macbook, right?

Ah I dunno, let me know how you go in the lab.

Thanks again,
Curtis

Hi,

Well the same SW is running on most Macs with the possible notable exception of the host controller driver. So SW is unlikely.

Unfortunately both our MacBooks are being used for urgent work for the next release, we have a task up to check this use case ASAP. Apologies for the delay!

Carlo

[paultzirides]

So I was gifted with a new MacBook from work (thanks boss!), and decided to try my luck with the following setup:

1. DVI monitor > Anker USB 3.0 Dual Video dock > USB port on Apple USB-C Digital AV Multiport Adapter
2. Monitor > HDMI port on Apple USB-C Digital AV Multiport Adapter
3. Apple USB-C Digital AV Multiport Adapter > MacBook

I tried it two ways

1. Everything connected and plugged in, then turning MacBook on.
2. ONLY Monitor > HDMI port, turning MacBook on, THEN connecting USB 3.0 Dock.

The first way (everything connected BEFORE turning on MacBook) yielded some inconsistent results. Sometimes everything would light up great and performance would be fine. Other times, the internal display on the MacBook would remain dark and performance would be flaky, with lots of horizontal "tearing" occurring with any interaction.

The second method produced much more reliable results. Apparently, having everything plugged in FIRST makes the OS behave strangely.

I tried the same experiment with a Plugable USB 3.0 Dual-Head Graphics and Gigabit Ethernet Adapter (Amazon link here), and it worked fine either way (or maybe it worked fine the few times I tried it, I don't use that one very often).

Either way, I can confirm that it generally does "work" the way I expected, but not consistently enough to feel 100% confident.

Additionally, we have been using this Dell USB-C dock at the office for all of the XPS laptops that we have, and it behaves very strangely. The MacBook recognizes the device, and the displays light up, but both external displays are mirrored, no matter which port they are connected to. I believe this is due to some proprietary Dell software that they are using to divvy up the displays properly. I will test to see if the following setup works as expected:

1. Monitor > Dell Dock > USB-C port Apple USB-C Digital AV Multiport Adapter
2. Monitor > HDMI port on USB-C Digital AV Multiport Adapter
3. USB-C Digital AV Multiport Adapter > MacBook

There's a lot of circuitry in there, and I don't have high hopes that it will work properly, but I will test anyway.

Let me know if you need anything from me in re: testing/logs, etc. to help out.

[Carlo]

Thank you Paul,

Very useful information.
This is not dissimilar from my experience with the multi port adapter. It's not behaving consistently and in my case was quite picky on the power output as well.

From what I've seen so far, USB-C with alternate mode and power delivery is very tricky to get right. We'll continue to run tests but the first hand experiences from the forum as invaluable.

Carlo

[paultzirides]

So maybe I spoke too soon. I've been using the Plugable dual-display adapter connected to the Apple adapter for a couple days now, and I have some updates on expected vs. observed behavior.

My MacBook is set NOT to sleep, but the displays turn off after 5 minutes. After coming back, the internal display does NOT light up as expected, but the external displays do (Monitor > HDMI on Apple adapter, as well as monitor > Plugable adapter). Unplugging the Apple adapter and plugging back in again causes everything to go back to normal. This is keeping in mind that the Plugable adapter is connected to the USB port on the Apple adapter.

Based on what I have experienced in the past, this is new behavior. Typically, when everything comes flooding back at once, things get weird, but it looks like simply unplugging the Apple adapter (and thus the connected Plugable adapter) and plugging it back in sets everything right again. Thankfully, this is a super easy fix, and not really a nuisance since we would have to do this constantly with the Dell docks anyway.

I will most likely be picking up a Plugable triple-display adapter based on my experience with their other products, and because it seems to strike the best balance between convenience and function. Based on my experience with the Apple adapter, I feel confident that this one will work consistently enough to not be a bother.

Thanks for all your support and hard work! Keep the updates coming

[Carlo]

We have run tests with a number of USB-C adapters and USB products with a 2016 MacBook without encountering particular USB issues.
We're going to test the 2015 MacBook next: the USB host controller is different.

We've observed the same issue Paul found: in systems with recent Intel GPUs sometimes the internal screen does not resume from sleep when USB screens are connected.
The same happens sometimes on warm reboots and we've seen a similar behaviour logging out and in again.
This is a Sierra issue not depending on USB-C but since all MacBooks have a single recent Intel GPU, they are all potentially affected.

If you see this issue please open a bug with Apple: this is the last severe issue not yet fixed in the latest Sierra beta!

Best regards,
Carlo

[wahlfeld]

Originally Posted by Carlo

We have run tests with a number of USB-C adapters and USB products with a 2016 MacBook without encountering particular USB issues.
We're going to test the 2015 MacBook next: the USB host controller is different.

We've observed the same issue Paul found: in systems with recent Intel GPUs sometimes the internal screen does not resume from sleep when USB screens are connected.
The same happens sometimes on warm reboots and we've seen a similar behaviour logging out and in again.
This is a Sierra issue not depending on USB-C but since all MacBooks have a single recent Intel GPU, they are all potentially affected.

If you see this issue please open a bug with Apple: this is the last severe issue not yet fixed in the latest Sierra beta!

Best regards,
Carlo

Not good that you're seeing issues too but it does make me feel better than it's a genuine problem and not something wrong with my device. It's great to see you and team working on this Carlo! I managed to get my hands on another USBC adapter to USB3/HDMI/SD card etc (forgot to check the brand) but I experienced the exact same behaviour as mentioned in my previous comments.

Keen to hear how you go with the 2015 Macbook testing.

Curtis

[Carlo]

Originally Posted by wahlfeld

Not good that you're seeing issues too but it does make me feel better than it's a genuine problem and not something wrong with my device. It's great to see you and team working on this Carlo! I managed to get my hands on another USBC adapter to USB3/HDMI/SD card etc (forgot to check the brand) but I experienced the exact same behaviour as mentioned in my previous comments.

Keen to hear how you go with the 2015 Macbook testing.

Curtis

OK so this has not been too easy for Kamil who tested here. This configuration is quite flaky in our tests.

There is definitely an issue. What we see happening connecting a USB 3 device to the Apple adapter connected to the MacBook is that sometimes only the USB2 part of the USB hub in the dock is enumerated.

Interestingly the OS then tries to re-enumerate and sometimes succeeds after 1-2 minutes. And sometimes the whole USB bus hangs. By inserting "slowly" the USB 3 cable in the adapter the chances of success increase (probably the adapter is sensible to the VBUS timing).
After noticing this, we went back to the 2016 MacBook and saw that the same was happening but the recovery is always succeeding for that model.

This is reproducible with other USB 3 devices so I'm not sure Targus could do something about it.

So not great unfortunately.

In your situation a possible workaround could be to use a USB 2 cable between the Apple adapter and the dock. This would be more reliable.
You would lose bandwidth but up to two 1080p screens it should be fine: we don't needlessly waste bandwidth as other technologies do (ahem...).

Best regards,
Carlo