Thanks to this new and interesting news:
https://discussions.apple.com/thread/8339158

I no longer have a working docking station solution for dual external monitors. I updated my Mac OS without knowing that it would break my external HDMI monitors.

I have a special need which requires me to have the ability to swap out which laptop I'm using on my dual monitors on my home desk. I swap between my home laptop, my work laptop, and my mac, depending on the situation. When all three devices supported DisplyLink, it was easy, I could just plug them into the dock. Now... not so much.

I can also use a Mac USB-C Digital AV Multiport Adapter successfully, but that gets me only one external HDMI monitor, not two. In fact, I have been successfully doing a hybrid where monitor 1 is driven off the HDMI plug from that thing, and monitor 2 is driven off the DisplayLink dock, for quite a while. But now, the second DisplayLink display just goes black.

I could upgrade to a pair of "Thunderbolt 3" monitors at great expense, and then my mac would work, but then my PCs wouldn't work with those monitors when I needed to do stuff on them. (would they? I don't understand the relationship between USB3 and Thunderbolt 3.) Problem is that all the new displays are super high rez, and honestly, what I really want is a pair of old 1920x1080 displays like I've currently got because the new super high rez displays are way too fine for my aging eyesight.

Also, I have this thing where one of the HDMI plugs going to one of the monitors goes to a HDMI splitter that goes to the TV next to the recording booth, allowing me to see/control the DAW from the booth. That's super useful and I don't want to lose that either.

I could become the operator from The Matrix and have four monitors I suppose, two PC and two mac. Again: expense of the extra monitors and added mounting bracketry.

I wonder if I'd be happy with one super ultra wide screen instead of two regular screens? Those are pricey too, though, and I have no idea if my Windows laptops' HDMI ports would even support it.

Any other ideas of what would work for me?

This sucks because I had a working system that I was happy with, even though it was kinda frankenstein, it worked, and now a software updated fried it all.

Heh, this one says it supports thunderbolt and USB-C and displayLink, but....
https://www.amazon.com/Plugable-Charging-Delivery-Specific-Thunderbolt/dp/B01FKTZLBS
... they just added text to the listing saying "NOT macOS COMPATIBLE (10.13.4 version and later)."

Heh.

Hm. If I remember correctly, these monitors I've got have both DVI and HDMI inputs and I can switch between those inputs on their front panel.

If I got something like this...
Thunderbolt 3 to Dual HDMI Adapter

Then I could theoretically connect the older gear with DVI cables and the mac with the HDMI cables and just switch between the inputs on the monitor front panels.

In theory.

Sad, though, that those dual-HDMI thunderbolt adapters don't also have a USB connection and a power charging pass through. At least I don't see one available. You either get a single HDMI and the USB and power charging pass through, or you get dual HDMI, not both. Does that seem to hold true?

TB3 uses the USB-C connector and allows extra things like power delivery, Displayport pass through as well as higher total throughput (40Gbps from memory). With a simple USB-C to DisplayPort or HDMI adapter you run your monitor directly off your internal video "card".

The DisplayLink stuff is a self contained video "card" that connects via USB. So in theory you can have many of them connected. I think I've seen a demo with ~16 connected at once.

USB3 is just USB (so no video passthrough or power delivery). So any display connected via a USB3 only port will require DisplayLink or similar adapter.

USB3 can be supplied via a USB-C physical interface so you can't tell by looking at the port.

I have two of these
Cable Matters Thunderbolt 3 to Dual 4K or Single 5K DisplayPort Adapter for Mac & Selected Windows
(Not Compatible with USB-C ports without the Thunderbolt Logo)

Each is plugged into a 2016 MacBook Pro 15 inch (one on each side). Total of four 4K screens are connected via these two adapters. I selected this particular adapter specifically for the additional bandwidth and video capacity of Thunderbolt 3 over USB-C adapters.

There are also USB-C docking stations that provide for two video outputs. Typically one output is HDMI right from the dock. The second video would be via a USB-C to HDMI (or to DisplayPort) adapter, daisy chained behind the dock to feed the second display.

Since I am Mac only, I also use a CalDigit TS3 Thunderbolt 3 docking station, recently superseded by the CalDigit TS3 Plus

Can you not just roll back to 10.13.3?

tanstaafl.

I used a DisplayLink USB 2.0 docking station for several years with my MacBook Air. While it ‘worked’, every single macOS update brought risk of problems, if not complete unusability. Eventually the problems would get resolved and I could have both external screens working again.

The DisplayLink support forums for Mac had a general sadness, with familiar postings of known problems, and monthslong threads waiting for a software update fix.

When I was finally able to buy the first generation of Mac compatible Thunderbolt 3 docking stations, I was happy to unplug that DisplayLink thing and set it aside.

There is a USB 3.0 DisplayLink chipset which is supposedly better supported (but see above). I have not used one, and have no interest in spending any more time trialing DisplayLink driver software and firmware, often only available as Beta and sometimes ‘released’

I do have four external displays connected to a single computer, but only two during my DisplayLink era.

Unfortunately this bug is across all DisplayLink devices, regardless of chipset.



That is something I am thinking about. However I'm not sure if there's an easy procedure for that. My google searches only result in information regarding how to roll back to an older "major" version rather than the small rollback I would want to do.



Thanks, I'm definitely going to investigate those docks. I initially discounted them since they only had 1 HDMI output but your hint that I could daisy chain a USB-C-to-HDMI adapter into them (something I already own) means that I could do that too.

This theoretically should allow me to switch back and forth between the PC gear and the Mac gear by tapping the "input" button on my monitor front panels. (PC Gear connected to DVI ports on monitors, Mac gear connected to HDMI ports on monitors.) Anyone see a flaw in that scheme that I might have missed? For example if the docks say that they're "USB-C" docks like those recommended ones, is there a chance that they're using DisplayLink under the hood or something? Or would a USB-C-to-HDMI adapter use DisplayLink under the hood?

Thanks, gang!

The CalDigit TS3 Plus is new enough to be not available on Amazon yet, but it looks real nice. I'll probably grab one once they're more widely available.

In the meantime, I did Amazon same-day-delivery on a less expensive thunderbolt-to-dual-HDMI plug adapter to get me by for now and to see if my scheme will even work.

This is a tricky bit. Thunderbolt 3 has a well defined video channel structure. The actual video processing happens inside the video chip on computer/laptop. Video bitstream flows over Thunderbolt 3, signal converted to HDMI/DisplayPort/DVI and down the cable.

USB-C has several ways to display video, you may have to read the details on each adapter or dock.

DUAL external video output can be quite different from single external video, USB-C may have limitations. I chose Thunderbolt 3 specifically to avoid USB-C limitations.

Thanks for that information. That's useful.

The device I ordered is pretty specific about being a thunderbolt 3 device with two HDMI outputs. It's not the same brand as the CableMatters one that you recommended, but it looks like it's the same class of device. (I ordered a different brand because I could get it faster.)

I'll be more careful if I ever get USB-3 type HDMI adapters to make sure they're not DisplayLink devices if I want to use them with a Mac.

Or anything other than MS-Win. They're pretty much a single-OS paperweight kind of device.

It's funny because before I got a Mac, I made sure DisplayLink worked with it. I used a friend's Macbook on my displayLink docking station to be sure. It only stopped working last Friday. It's been real good in the meantime.

Don't say I didn't warn you

http://empegbbs.com/ubbthreads.php/topics/355335/Re:_DisplayLink_review#Post355335

Last time DisplayLink was broken on OSX for something like two years before they managed to fix it.

That was basically my solution when it happened to me last time DisplayLink got broken by OSX changes. I switched from MacBook screen + 2 * 1920x1080 screens, to MacBook screen and one 27 inch 2560x1440 screen.

Nowadays that is what I prefer, one biggish monitor above my MacBook screen (I'm one of these odd people who use their MacBooks open plugged into a second screen rather than closed with external keyboard and pointing device).

I make extensive use of keyboard shortcuts in BetterSnapTool to actually use my 27 inch monitor as if it was two portrait-ish monitors.

I also have my MacBook open in front/below the external displays. I also upgraded to 4K screens a year ago and highly prefer them over the HD (1600x1200) I had before. Font sizes are not a problem as the Mac lets me scale the UI to suit my (not so young anymore) eyes.

That said, I am using 32” 4K screens which is larger than my television was years ago

I considered buying super wide displays but found that the vertical resolution was not much better than plain old HD. For my use case curved screens introduced a visual effect that I disliked.

I shall look into the BetterSnap Tool , might be useful.

Yes, the Mac is much better about font and icon size scaling than Windows is. Windows is trying hard to get better, but I still run into tons of problems with it. For example, let's say I'm on the Mac and I'm remote desktopping into a Windows box, and I want to increase the scaling on the Windows screen, Windows literally won't let me change the scaling in RDP mode. Other times, I run into problems where the scaling is wrong depending on whether I booted the Windows box while docked to an external screen or whether I booted the laptop on its own screen, and then when I dock, not all the scaling settings change back to where they should be. And then there's a problem with older applications which don't respect the scaling, etc.

So since I still use Windows in the mix for various things, I still prefer a screen that's at about 1920x1080 rez so that when the scaling screws up I can still read things. The 1080p resolution is a perfect sweet spot for my eyesight, balancing the amount of data I can fit on the screen at once with the average size of the text of most programs.


Which would be a good feature for me.



Aha, that's a really good point. I could see the curved screen being great for gaming, or for watching Cinerama type movies in ultra wide screen. But for any kind of graphical editing, CAD, desktop publishing, or coding, anything where parallel lines are important, I could see the curve potentially really screwing me up.

And it looks like all the ultra wide screens are curved, so, that's a no go for me.



Fair point!

In the meantime, I got things working well again last night.

Temporarily I connected the Mac to two monitors using one each of these, which I already had on hand:
Anker USB-C to HDMI Adapter
Apple USB-C Digital AV Multiport Adapter

Works, but a little unwieldy. I ordered one of these same-day:
Plugable Thunderbolt 3 Dual HDMI 2.0 Display Adapter
... And that works too.

Interesting side note. I also have a weird frankenstien setup where I pipe one of the HDMI outputs through a DVI splitter box (using DVI-HDMI adapter plugs) so that my main 1080p monitor is also echoed to an old LCD TV parked just outside the recording booth. With this old scheme, it used to work fine, the 1920x1080 output would simply appear duplicated on the TV. The TV would scale down the 1080-line image to its native resolution (720p) and it would be enough for me to control the DAW when I was solo-tracking in the booth, and when I went back to the desk to work with the DAW in detail, it would be the same screen, just sharper because it was at native 1080 resolution instead of scaled down for the TV set.

With the new adapters, that scheme no longer succeeds. Something about either the video adapters, the splitter (I have two different ones and tried both), or the new OS update, prevents it from working the way it used to. Now the Mac will only use the lowest common denominator resolution between the displays going through the DVI splitter, and I can't force it back up to 1080 (even with the "Alt+click on Scaled" trick on the Mac). So my desktop screen was only running at 720p, the TV's resolution, which wasn't livable, I needed my 1080-line sweet spot at my desk.

So for now, I'm using a combination of the Plugable dual-HDMI adapter going to my two desktop 1080 monitors, and also the Apple AV Multiport adapter for power, USB docking, and also its HDMI cable goes straight to that LCD TV outside the booth (no splitter any more). So now it's actually three independent external displays instead of two plus a splitter. And they all run at their native resolutions. So this is actually pretty good.

For the Windows PC side of things, the DisplayLink dock still works great and I have it going into different inputs on the two 1080p monitors. The monitors have DVI and HDMI inputs, and the Mac now goes into the HDMI inputs and the DisplayLink dock goes into the DVI inputs, and so I just switch between the inputs depending on which machines are hooked up at the time.

So I've got it all working now, though I'm waiting on some extra cables to make the connections a bit cleaner. And I still want to get a nice Thunderbolt 3 docking station to bring everything down to a single wire connection to the Mac.

By the way, for posterity:

I'm told that I could simply use the Time Machine backup system to roll back my system to 10.13.3. Since I religiously keep two redundant backups, this should theoretically be easy.

I hadn't realized that Time Machine could roll back the OS, I thought it was just for my documents. I've never actually needed to use its restoration features before.

I don't need to do it now, since I'm improving the video connections to remove my dependence on their support for DisplayLink, but it's worth noting that it would have been an option for me.

Okay, now I have a question about extending Thunderbolt 3 cabling.

I want to be able to extend the "reach" of these two devices currently hanging awkwardly off the MacBook Pro:

1. Apple USB-C Digital AV Multiport Adapter
2. Plugable Thunderbolt 3 HDMI Adapter

They both have very short cords, meaning that they hang off the side of the desk where the Mac is perched and there is stress on the USB ports on the Mac that way. (The other way, with them lying on the desk next to the Mac, means they get in the way on the desktop, there's not enough room for them to be livable that way).

I figured, while I'm in the process of re-doing the video wiring, I'll also get some extension cables to fix that problem. I need about 6 feet of extension to do the thing I need to do.

Well, I ordered a couple of 6ft TUSITA USB-C Extension Cables and they flat out don't work for this purpose. For power supplying through the Digital AV multiport adapter, it's a no-go, the Mac keeps going back and forth between charging and not charging every few seconds, emitting a "BONG!" sound every time it flips. And for the HDMI adapter it just flat out doesn't register a connection at all.

My next thought was "oops, the cheapass cables I bought don't say Thunderbolt on them, so I should get nicer ones instead", and looked for ones which did say Thunderbolt on them. The first ones I found were these DISDM extension cables which say "thunderbolt" but I'm very VERY leery about them because of the following text in a review:


There is a similar comment in a product review for a similar cable by Dreamvasion, describing the exact same issue that I encountered.

So I'm actually not seeing any extension cables that will work for what I want. There's are multiple different certified 40gbps Thunderbolt cables in my desired length, but they won't plug into the devices I need because they're male-male. I need a female-male because the devices in question don't have a female plug, they have a male dingledangle instead of a hole. I'm afraid if I try a short fem-fem adapter to get the dingledangle to connect to the certified 40gbps cable, that I'll simply encounter the same problem after having already shelled out the extra scratch for the certified cables.

There's this Apple Insider article which seems to confirm my fears. They recommend the same groups of certified 40Gbps cables that I found above, but don't have any suggestions of extenders to hook to the dingledangles.

Anyone have any advice in this area?

I think you have run into a reason why the proper docking stations havie a female socket for the Thunderbolt 3 (or USB-C) cable coming from the laptop. An adapter with a pigtail lead is essentially stuck with that cable length. A docking station allows you to buy the Thunderbolt 3 cable length and type (active or passive) necessary to get the required bandwidth for your application).

Similar story for USB-C where you need longer cables.
Notwithstanding the whole power delivery aspect.

I don’t know if there is even such a thing as an ‘extension cable’ for either Thunderbolt 3 or USB-C pigtail adapters that fits within the specifications for those standards.

My own approach was to accept that the docking station and the dual DisplayPort adapters were all going to be present on the desk, tethered on fairly short cables and sort of tucked behind the laptop.

The linked article was quite well done.

Cool, thanks.

OK, well since my long term plan is to get one of those nice docking stations, I'll go with that, assuming I can find a cable that'll let me connect to the dock at 6 feet length. I might get away with 3 feet with some finagling.

Now, another interesting question that digs deep into Mac architecture.

I'm able to use both of these adapters on the Mac at the same time:

1. Apple USB-C Digital AV Multiport Adapter
2. Plugable Thunderbolt 3 Dual-HDMI Adapter

When they are working, I get a total of four available independent screens:
- The Mac laptop screen.
- The dual HDMI outputs going to the two 1080p monitors from the Plugable Dual-HDMI adapter.
- The single HDMI output from the Apple USB-C adapter, going to my 720p LCD television near the recording booth.

BUT.... there seems to be a "catch".

If I plug both those adapters into the two ports on the SAME side of the Mac, for example, plugging them both into the two ports the right side of the Mac, then one of the monitors is always blank. Either the TV screen doesn't show up as an available device, or, the right-hand of the two 1080p monitors doesn't show up as an available device. (Depends on which adapter was plugged in first).

If I plug both those adapters into OPPOSITE sides of the Mac (one right side and one left side), then all four monitors work.

Why?

This puts a damper on my idea of having just a couple of cables dangling off the left side of my desk, and no interference cabling coming out the right side of the Mac into my desktop clutter workspace.

Clarifying quesion: You are doing two cables? One to the docking station and one to the dual DisplayPort adapter?

If so, then question: Is there a reason you're not cutting it down to a single cable by daisy chaining the dual DisplayPort adapter into one of the ports on the docking station? Does that fail to work correctly for some reason?

Is this one of the recent MacBook Pro 13 inch models ?

Some of them have a different Thunderbolt setup on the two sides of the machine, something to do with not enough PCI express buses.

And if it isn’t, PCI express lanes could still be the issue. I expect the have to route a bunch of them to the ports on one side and a bunch of them to the ports on the other side. So if you stick to using just one side you are restricting yourself to using only part of the machines available IO.

Yet another reason why dedicated ports was so much more simple than USB-C/Thunderbolt 3

The maximum number of displays that a single Thunderbolt 3 chip can feed is two, on the Mac.

The larger MacBook Pro with Thunderbolt 3 have two chips, one feeds the left side, one feeds the right side. So I have two monitors connected to the left side via a single adapter and everything else is connected to the right side.

Right side has a single Thunderbolt 3 cable to docking station, then daisy chain to the other two displays.

Hmmm, maybe I should swap the docking station to the left side port ... I seem to recall the left side ports have more bandwidth? Need to check that!

I solve that problem with sticky-back Velcro.

tanstaafl.

Aha, that explains it. Yeah, I've got a 15" Macbook Pro.

Blast, though, it means that, no matter what, I'm using two cables, and they have to be inconveniently placed on two sides of the Mac instead of one.

Maybe a docking station with an external GPU is in my future, if such a thing is being made some day.



According to this, that limitation is on the 13 but not the 15 if I'm reading it right:
https://www.macrumors.com/2016/10/28/macbook-pro-tb3-reduced-pci-express-bandwidth/

Answering my own question:

Even with that CalDigit TS3 plus, which is probably the most powerful available Mac docking station out there, you still can't do this. I talked to CalDigit support and their dock can support a maximum of two external displays: One via its own video port, and one via its thunderbolt port. Attempting to daisy chain additional video adapters into its Thunderbolt port will not gain me any extra displays.

I'd be happy with two displays total if only my splitter trick for the recording booth monitor had kept working. Alas, this looks like it's not the case.

I've got a few of these. They're grippy, they're surprisingly weighty, and they're pretty good at keeping your cables on your desk.

I also have some sticky-back cable grips. A quick search found me these, which aren't the same as the ones as I've got, but it looks like they'll do the job.

But, then again, I've also got holes cut into my desk and a few Desk Grommets strategically located.

That's when I haven't simply cable-tied (or velcro-tied) the cables to my monitor mount arms.

Edit: while looking for more examples of cable-tidying porn, I found these cable hooks. Tempting.

Edit Edit: They don't appear to be easy to find, but it occurs that a set of cheap, but not too cheap, storage hooks would be suitable. Something like this, but maybe with less overkill.