M1 Pro MacBook Pro, CalDigit TS3+, and dual monitors issue

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Level 1

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M1 Pro MacBook Pro, CalDigit TS3+, and dual monitors issue

I saw another user post at solution at the thread link below, however, I have a followup question for him which I cannot post to his thread because the question is so old the community website won't let me.

In his response, he states he describes his setup as the following:

"I now have one monitor going from a new HDMI 2.0b Cable -> HDMI to USB-C Adapter -> USB-C Monitor port on the TS3+, and the other monitor is straight HDMI to the MacBook Pro's HDMI port."

To my knowledge, M1 Macbook pro doesn't have an HDMI port. It only has two thunderbolt 3 ports. So is his post written incorrectly or does he have an M1 Macbook Max or Ultra and he didn't include that info?

If anyone else has figured out a workaround to run two monitors off a 2020 M1 Macbook Pro using the Caldigit TS3+, please post your process and/or links to tutorials. I've searched and haven't found on my own.

Thanks so much --

M1 Pro MacBook Pro, CalDigit TS3+, and De… - Apple Community

MacBook Pro 13″, macOS 14.7

Posted on Feb 10, 2025 9:32 AM

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Answer 1

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Jordanwra Author

Level 1

4 points

Feb 11, 2025 5:35 PM in response to Grant Bennet-Alder

Thank you so much for the in-depth explanation. I really appreciate you taking the time to go into so much detail.

Bottom line appears to be one can't run two extra monitors directly off an external hub off the macbook pro model I have. That's beyond disappointing. Apple should have been clear about this when they made the offering. Moreover, they should have taken the "pro" off the name and simply called it a "macbook" and offered it at a more reasonable price.

In conclusion, for anyone else who may have opted for this older model, I did find a solution that didn't cost much extra money:

First, if you're going to use the "display port" on the Caldigit TS3+, you can't use it if you don't have an "active" display port wire. It won't work with the standard, it must be "active" (i.e. it has a chip inside the wire).

Second, you can create a setup that will allow you to run 3 screens while using the Caldigit TS3+, provided your 3rd monitor is Airplay compatible. For example, my setup includes the M1 Macbook pro as my first screen, a Wacom Cintiq 22HD for my second screen, and a Sony 40" 1080p tv for my 3rd screen. Most people will have a smart TV which will very likely have airplay natively. I'm using an old non-smart LCD I had laying around, so I opted to purchase a Roku Express which has Airplay. The cost was only $17.

Grant is correct about there being some latency, but, I'm happy to report it is EXTREMELY minor and barely noticeable. I'm guessing the quality of your home wifi network will affect your experience, but I'm really not noticing a difference.

Thank you all for chiming in on this topic, your help is appreciated!

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Answer 2

samtenor

Level 4

2,074 points

Feb 10, 2025 12:39 PM in response to Jordanwra

I think you forgot the M1 MacBook Pro - has another 2 models, 14" and 16" , that these 2 came out at 2021.

These 2 models both have HDMI port and also can support 2 external displays.

If you are trying to get multiple external displays with 13" MacBook Pro (M1) - regretfully, you are out of luck.

Best

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Answer 3

Feb 10, 2025 5:42 PM in response to Jordanwra

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.

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Answer 4

Feb 10, 2025 11:30 AM in response to Jordanwra

You can't get 'all the displays you want' unless the processor has internal display-generators to support them.

The same rules we learned for the M1 and M2 and M3 mostly still apply to the M4 models. Display interfaces are generated deep inside the system on a chip. How many there are depends on the exact type of Processor:

M3 (plain) like the 13-in and 15-in supports up to ONE External fully hardware-accelerated external display.

Except the M3 MacBook Air models with 13 or 15-in display, (and certain M3 plain MacBook Pro models when running 14.6 or later) which can support a second external display instead of the built-in display when you close the cover on the built-in display. This may require MacOS 14.6 or later.

M4 (plain) supports up to Two fully hardware-accelerated external displays (three for Mac mini)

M4 PRO processor supports up to Two fully hardware-accelerated external displays. (three for Mac mini)

M4 MAX processor supports up to Four fully hardware-accelerated external displays.

M4 ULTRA processor supports up to Eight fully hardware-accelerated external displays

Tech Specs now available here:

MacBook Pro - Tech Specs - Apple

so what MacBook Pro PROCESSOR is in yours? {(plain), PRO, MAX, ULTRA} and what model year and M-number?

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Answer 5

Feb 12, 2025 8:41 AM in response to Grant Bennet-Alder

My statement about ACTIVE cable/adapters, while in may be accurate for longer ThunderBolt cables, does not apply here. The correct information is this:

DisplayPort uses 3 Volts signal levels. without "Dual Mode" (where the Originating device boosts its signal levels to HDMI's 5 Volts levels) the 3 volt signals are not detected at the display.

An ACTIVE adapter or adapter/cable has signal re-Drivers, and can use power from the power lead in the interface to re-generate the signals at the 5 Volts level.

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Answer 6

Jordanwra Author

Level 1

4 points

Feb 10, 2025 5:13 PM in response to samtenor

Ah. That was the missing puzzle piece. Thank you for that.

It's not like I'm looking to run high resolution. The monitors I'm trying to export to are both 1080p. Videos like these are what's throwing me off though.

How is it this guy is making it happen with displaylink?:

https://youtu.be/k1J3lSZfrko?si=wtcya0eaxq69K7Rm

My research says the Caldigit TS3 won't work with displaylink (grumble). A friend has the same model macbook I have and he's using airplay to export to a second monitor. I was trying to avoid that approach as I don't want the latency issues.

If anyone has additional thoughts, please chime in? Thanks so much to both of your for taking the time to answer.

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Answer 7

Feb 12, 2025 6:20 AM in response to Jordanwra

RE:Airplay

The data stream to support an ordinary external display on a cable can approach 20,000 M bits/sec for up to 4K displays. That is a LOT of data, and it is unrelenting, refreshing 60 times a second or more.

Your Home Wi-Fi has at BEST around 1,000 M Bits/sec, and typically less.

You can't get a 20,000 M bits/seconds smooth scrolling and adequate full motion video expererince using Airplay either, but is your data is slow-to-change (i.e. is NOT gaming or editing movies) you might be able to "get away with it" for certain uses.

Cable lengths for direct DisplayPort displays are limited to ONE meter or less -- unless as you said you use an ACTIVE cable. These may have drivers to convert to a fiber-optic down the (much longer) length of the cable, then back to electrical at the far end. They can be a bit pricey.

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M1 Pro MacBook Pro, CalDigit TS3+, and dual monitors issue

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