How can I use dual monitors with my MacBook Pro M2?

Apple-Silicon 2020 M4, M3, M2, and M1 13-in MacBook Pro and Air and similar models with M-series (plain) processors are extremely-capable entry-level computers. They can support the internal display AND an External display up to the previously unheard of size of the Apple 6K display at billions of colors. But only ONE in addition to the internal display.

This may not match the way older computers forced you to work, since older computers were not able to support a really large external display. But it is NOT a defect. The spec was available long before you could purchase the computer.

The Apple standard for its built-in hardware-accelerated displays, makes them suitable for full-motion video for production/display of cinema-quality video with NO dropped frames, and NO dropouts or partial-blank scan lines due to memory under-runs or other issues. This requires a hardware rasterizer/display-generator for each fully-accelerated display, supported by Huge memory bandwidth to refresh each display 60 or more times a second.

If you need more hardware-accelerated displays than the built-in and ONE external display, and an un-accelerated iPad if desired, you probably need a more capable computer.

MacBook Pro M3 (base) models with 14-in display supports the same ONE external display.

On the MacBook AIR M3 (base) models with 13-in or 15-in displays, you can close that lovely display you paid dearly for, and use the display generator for a second external display, INSTEAD OF (NOT in addition to) the Internal display.

If you are doing ONLY program listings, spreadsheets, stock quotes and other slow to change data, there are some other solutions, but they require you to make some strong compromises.

Executive summary: More than ONE additional Hardware-accelerated display can NOT be added to the entry-level 13-in or 15-in M1 or M2 or M3 or M4 systems.

Apple_Bottoms wrote:

Thank you for your reply. I’m so confused how I was able to in the past (like last week). I used the display link manager and all was well now NOTHING 😢

To restate what Mr. Bennet-Alder said, the DisplayLink driver by itself gives you nothing.

You said that you could use two monitors with your old docking station, but not with the Ivanky Fusion Max 1. That tells me that your old dock had a DisplayLink chip set, and implemented one or more outputs using it. It also tells me that (a) your new dock does not have the DisplayLink chip set at all, or that (b) if it does, you are not hooking up at least one of your monitors to an output driven using the workaround.

So let's take a closer look at the new dock …

Ivanky – FusionDock Max 1

This is a $440 Thunderbolt dock. Most Thunderbolt docks run their display outputs off hardware-supported video of a type that Macs support – which means that you get a high-quality video connection, but you also do not get the ability to attach more displays than your Mac supports.

A few Thunderbolt docks with more than two places to connect displays drive displays using DisplayPort MST or the equivalent, which Macs do not support. I've only ever heard of ONE Thunderbolt dock (out of many) that used DisplayLink or a similar workaround. Thunderbolt dock vendors appear to believe that customers in the market for high-end, expensive docks are not interested in connecting monitors using workaround technologies and the compromises that may go with them.

This dock has TWO Thunderbolt 4 chip sets and has TWO upstream Thunderbolt connections to the host Mac. Thus if you have a Mac notebook with a Max chip, this dock can drive three or four displays. If you have a Mac notebook that has a plain M-series chip or a Pro chip, it can't do that because your Mac simply does not have enough display generators to provide the dock with three or more signals. Basically, if you have anything less than a Max chip, the dual Thunderbolt chips, dual Thunderbolt connections, and high price of the dock might get you more total bandwidth for DRIVES, but won't do a thing to increase the number of displays you can use.

It's a bit like paying a contractor to build a four-lane driveway in front of your house when you only have one or two cars.

From Ivanky's description of their dock. Your 13" M2 MacBook Pro would fall under the first column.

Macs support connecting one hardware-supported display to a plain USB-C dock. Up to two to a Thunderbolt dock if the Mac in question supports multiple external displays. (A 13” M2 MacBook Pro with a plain M2 chip doesn’t.)

<< display link manager. >>

DisplayLink technology creates a "fake" display buffer in RAM, sends the data out over a slower interface to a stunt box with DisplayLink custom chips that put that data back onto a "legacy" interface. It is not a true "accelerated" display, and it can suffer from lagging. Just adding the DisplayLink Driver is not adequate to get a picture -- you need a DisplayLink "stunt-box" or a Dock that includes DisplayLink chips.

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It may be acceptable for a second display showing slow-to-change data such as computer program listings, stock quotes, or spreadsheets, but NOT for full motion Video, not for Video editing, and absolutely not for gaming. Mouse-tracking on that display can lag, and can make you feel queasy.

In a pinch, it may even play Internet videos (as one user put it) “without too many dropped frames".

If you are only doing program listings spreadsheets, stock quotes, and other slow to change data, DisplayLink can work for you, but requires you to make some strong compromises.

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It is really nice to know that you can use a DisplayLink display if you MUST have an additional display for some of the types of data I mentioned. But that is NOT the same as the computer supporting a second, built-in, Hardware-accelerated display.

These displays depend on DisplayLink software, and are at the whim of Apple when they make MacOS changes. There have been cases where MacOS changes completely disabled DisplayLink software, and it took some time for them to recover.

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I think the Big Surprise for a lot of Hub/Dock buyers is that they thought they were getting a "real" display, but actually got a DisplayLink "fake" Display. If you got what you expected in every case, I would not use such pejorative terms to describe DisplayLink.