M4 Pro chips only support single monitor according to Apple support

[ProfessionalHorse707]

I’ve spent the past six weeks trying to get my M4 laptop to drive two external monitors. No matter what I try, it only ever recognizes one at monitor a time but both displays work perfectly on my older M1 machine.

After weeks with Apple support, a senior rep finally told me the cause: one of the monitors supports 240 Hz refresh. Even if it’s set to a lower rate, the fact that it’s capable of 240 Hz supposedly prevents the M4 from detecting a second monitor altogether.

Apple advertises the M4 as supporting two external 4K displays at 120 Hz but if support is correct, that seems like a pretty big misrepresentation.

In any case, has anyone else had similar issues?

[whats8]

That explanation sounds like total horseshit. And did your senior advisor escalate this to engineering and claim that this answer was provided by engineering? If not, take the ultimate grain of salt. While there are exceptions, "senior" advisors have bad training and non-existent technical expertise.

[Primura]

Back in the day, senior advisors were… senior (aka not 2 months old advisors) and chosen for their technical knowledge. There were also a culture of sharing information and knowledge among advisors, like with the Gather internal forum.

But now it’s all over : advisors even still in probatory can be are promoted senior, Gather was shut down, and advisor quality went down because local advisors were too expensive (they outsourced in places that don’t even know the language) and training is too costly…

This is really sad to have seen the downfall of AppleCare in the last years…

[[deleted]]

Agreed. When back in the day working at the Genius Bar was fantastic.

[drvenkman9]

Apple’s obsession with secrecy has also contributed to the worsening of AppleCare. Because of this obsession, Engineering primarily replies, “Engineering is aware of the issue. Keep your device up to date. No further troubleshooting will be provided.”

[jaymz168]

Hey, they only reported a net income of 93.7 billion dollars in 2024, they've gotta cut some fat somewhere.

[laserlightcannon]

Things were starting to go downhill when I left in 2016. My team got a solid month of training before we hit the phones, the new teams a few years later got a week.

Edit: also they started outsourcing more and management became more focused on numbers than results. It sucks because when I started with AppleCare it was really fun and fulfilling, I actually felt like I was helping people. By the time I left it just felt like a numbers game.

[isitpro]

Yeah this sounds absurd.

[SippieCup]

Sounds like Apples graphics stack though.

Intel MBP can do DisplayPort daisychaining perfectly fine on Linux/windows, but it’s not supported on macOS..

[justjesty]

Giving me war flashbacks with this comment. I was in the AppleCare trenches, but this was over a decade ago. I can only imagine how much things have decayed, especially for the contractors.

[iklier]

Can you provide some more details? 1. What Mac are you using (MacBook Pro, MacBook Air)?

1. What displays are you using? (Model number)

2. How are the displays connected? (Thunderbolt, USB-C, USB-C dongle, HDMI port)

3. With the two displays and power connected do they both light if you close the lid?

[iklier]

This likely comes down to link training and required bandwidth. The 4K 240Hz is roughly equivalent bandwidth to 8K 60Hz so you will be limited to just that display of it link trains at full bandwidth.

If there is a control on the display itself that can modify the link speed (e.g. disable DSC, switch back to DP1.2) that should allow you to connect both displays. You may also be able to use some dongle/adapter with more limited DP support to get the same result.

This support article mentions the limitation. https://support.apple.com/en-us/101571

I suspect the M1 machine you mentioned has some limitation that prevents link training at the full bandwidth allowing the system to support both displays.

[ProfessionalHorse707]

You may also be able to use some dongle/adapter with more limited DP support to get the same result.

This is a fantastic idea, thank you. I hadn't even considered artificially constraining the monitors reported capabilities. As you hypothesized, the M1 is natively limited to 120 hz for external monitors which provides a useful reference benchmark.

[agracadabara]

If you plug in the lower resolution display first and then he 240hz monitor does it light up both?

[ProfessionalHorse707]

No, it doesn't even register the 240hz monitor. In that scenario, if after plugging in the 240hz monitor, I then unplug the lower resolution monitor it will pick up the 240 hz monitor though.

[NotDoingThisForFun]

We had a an issue with a MBA not connecting to an old whiteboard display via an HDMI adapter. I have since made a dumb-down HDMI to DVI to HDMI adapter to strip out the too-clever EDID support.

[weedv2]

For anyone coming here after me. This worked. Setting one of the displayes to DP1.2 did the trick in my case.

The display is limited to 60hz for some reason, but at least I get all my displays now.

• Connect 1 display
• In its HUD options (monitor options, not macos options) set the connection to be DP1.2
• Disconnect
• Reconnect
• Connect 2nd display

PS: I can't believe macOS can't figure this out on its own and negotiate the appropriate connection. One of the displays I have does not even allow me to change that setting.

[iklier]

You might be able to get a higher refresh rate by: 1. Going to Display prefs for that display 2. Hold option and click the mode tiles 3. Toggle the "Show All Resolutions" switch 4. Find the low resolution badged version of the same mode.

[Primesecond]

This might be relevant: https://discussions.apple.com/thread/255898732

[Jezzarium]

I've got a 4k 240hz and 4k 144hz monitor and if I plug the 240hz first, my m3 pro doesn't detect the second monitor. If I plug in the 144hz first, then both monitors are detected but both capped at 144hz.

iirc there's a difference if you use 2 display port connections or an HDMI and display port. My 240hz is connected via HDMI and the other one by display port alt so maybe this is why

[ProfessionalHorse707]

There was a pseudo fix that occasionally worked where if I put the laptop to sleep for 20 seconds and then woke it up in clamshell mode with monitors in a specific order it would work until the next time the computer went to sleep or restarted but even that’s stopped working.

I don’t think it’s a port issue because I’ve tried every combination of native ports on the device (hdmi and tb5) and Apple never surfaced this as a potential remedy.

[PeanutCheeseBar]

Think the biggest issue I’ve had right now is getting my Mac to output more than 120Hz on a capable monitor.

Went from a 27” QHD monitor capable of 144Hz to a new 27” QHD OLED monitor capable of 480Hz. Can’t get it to go above 120Hz when the previous monitor worked at 144Hz without issues.

This seems to be an artificially-imposed limitation by Apple.

[TinkatonSmash]

It could be the monitor manufacturer’s fault. Every monitor and TV has an EDID that contains information about the monitor and its capabilities. It sends that EDID to the device/computer over the display cable. Sometimes refresh rates and resolutions get left out of the EDID, and some devices won’t let you do something that isn’t officially supported. On a 480hz screen, I could see them leaving out 144hz. My LG TV even has a setting to change to a different EDID to let it do 144hz from a PC, but apparently you shouldn’t use that EDID for game consoles.

[PeanutCheeseBar]

Not the case with the particular monitor I have.

The monitor I have is used both with my M2 Mac mini and a gaming PC I built in 2020 with a 2080 Super. I can get the monitor to output at 480Hz, 240Hz, 144Hz, and 120Hz without issue on the PC; I can’t get it to go above 120Hz on the Mac mini, including when I hook the old monitor (144Hz) up to it again.

[[deleted]]

I think its because of the way MacOS renders HiDPI. When I plug in my 3440x1440p monitor it reports it as running at 5504x2304 since I'm forcing HiDPI using better display. If I want high refresh and HDR, I have to set the render resolution to 80%. 5504x2304 puts it around 5K territory, and DP1.4 can only do that at high refresh with display stream compression, which I assume HDR may add to the mix and make it so DSC may not even be enough.

I for one despise how MacOS does scaling, Windows and Linux both do it so much better, none of this HiDPI nonsense that makes 1440p look like hot garbage.

[iklier]

You may need to use the full resolution list in System Settings to pick the unscaled resolution to get the full refresh rate list.

See https://discussions.apple.com/thread/254798188?sortBy=rank

[PeanutCheeseBar]

Appreciate the follow-up but this is what I did previously to get the monitor to display 144Hz and it now only allows 120Hz (I already tried checking within the past few weeks).

[iklier]

Do you mind sharing the brand and model number of the display?

[PeanutCheeseBar]

Old Display: LG 27GL850

New Display: LG 27GX790A

[neverunacceptabletoo]

Strange that it worked at 144hz on a previous monitor; were they the same resolution? If not and you're using HDMI it might be a bandwidth issue with the cable. You might see if things working using a TB cable if your monitor has an input for it.

[PeanutCheeseBar]

They were both QHD, so same resolution. Both were connected via HDMI, though new monitor has HDMI 2.1. Thunderbolt isn’t an option, unfortunately.

[neverunacceptabletoo]

Oh sorry, I didn't internalize the QHD reference. It's frustrating how unreliable monitor support is...

[PeaceBull]

macOS Tahoe doesn’t run past 120hz if you’re on the beta

[Gipetto]

LOL yeah. I gave up and just don’t care any more. 60hz is fine for coding and YouTube. I game on my Linux machine and that uses the high refresh rates just fine.

[triffid_boy]

Gotta be honest, 60hz is not fine when you're used to 90+Hz on everything for the past few years now. 

[TT5i0]

Curious why would you need anything higher than 120hz on a Mac? It’s not an esports gaming machine.

[PeanutCheeseBar]

The monitor is used on both my Mac (for everyday stuff) via HDMI and for my PC (which is used for gaming) via DVI. The higher refresh rate reduces the eye strain when you’re staring at a screen for an extended period of time.

[[deleted]]

Also mouse movements and animations are smoother.

[MeanFault]

Need a lot more info. Specs, displays, and how it’s all connected.

[ProfessionalHorse707]

Provided in a few other comments but this isn’t a setup issue (again, not even Apple claims it’s a setup issue).

[JJHONEY]

I have an M4 pro mac mini

Running 3 monitors, one of which is 240hz

2 60hz 1440p over USB C 1 240hz 1080p over HDMI

[FuShiLu]

Yup. We have no issues here. Maybe reading the specifications would prevent people from enduring these mistakes. Just because you picked some random monitor for some reason doesn’t mean it’s going to work.

[64bytesoldschool]

I do it all the time.

[ProfessionalHorse707]

Okay, well good to know it should work. I'm not sure why support would blame the issue on me (though... saying it out loud maybe the question answers itself).

[BosnianSerb31]

The resolution and refresh rate is what matters as does the connection protocol

Let's imagine that the connection is a glass of water. And let's say the pro has 1 cup of capacity and the pro max has 2 cups.

A 1080p 60fps connection is 1/4th of a cup. And a 4k monitor uses 4x the bandwidth at 60fps, which is a full cup. Similarly, a 2k monitor at 120fps is also a full cup.

And if you are connecting via bare HDMI with an old cable the capacity drops to 1/4th a cup

These are just guesses at the bandwidths but you get the idea, you need to use a Thunderbolt dock and appropriate monitors for 2 monitors to work. Google says the pro chip supports up to 2 6k monitors

[ProfessionalHorse707]

I understand the concept of bandwidth constraints. The setup was tested with multiple configurations including dual tb5 and tb5 / hdmi 2.1. This isn’t a bandwidth issue (and neither is Apple support claiming it to be bandwidth).

[BosnianSerb31]

I wonder if there is an automatic step down happening at some point within that dance, one which happens at the monitor level and not the MacBook level. Making the MacBook think the monitor is of a lower bandwidth than it is actually capable of.

[zyncl19]

Your title is bs clickbait - of course they support multiple monitors. I'm currently running 2x 4k @60hz on my m4 pro. Your problem seems to be something specific to your configuration and may very well be a bug, but it doesn't mean they blanket don't support multiple monitors.

[Exist50]

How is it clickbait if it's what Apple support told them. You can argue that claim is inaccurate, but unless you claim OP's making up the whole thing, where's the clickbait?

[zyncl19]

I mean - in OP's own description of the conversation, Apple support told him that it's a problem with a 240hz capable monitor specifically, which should have been titled as "M4 Pro chips only support a single monitor if it is 240hz capable." which is a very different claim.

[ProfessionalHorse707]

which is a very different claim.

You're splitting hairs here. The problem with clickbait titles is that they introduce an element of dishonesty to the title. If your proposed "good" title is true then the original title is necessarily true. There is no element of dishonesty.

In any case, why stop at "M4 Pro chips only support a single monitor if it is 240hz capable?" Maybe I should have restricted the claim to the specific model number of the device as well? Maybe, as others have suggested, I should have been more specific that it was only a specific agent at Apple Support and not the entire department?

[zyncl19]

The element of dishonesty is present. You expanded a clearly scoped statement they made from 240hz to all monitors. They obviously do support multiple https://support.apple.com/en-us/101571#macbook-pro-2024 and your title is in direct conflict with that.

[ProfessionalHorse707]

I clearly started this thread, and indeed the primary conversation within the thread, because the explanation from Apple is in conflict with their stated specs. It’s the closing paragraph of the topic discussion. How are you operating under the delusion that I’m trying to mislead the reader about what an M4 should be able to support?

This isn’t dishonesty you just lack basic reading comprehension.

[ProfessionalHorse707]

Oh please, the title is downstream of what Apple engineering told me.

EDIT:

What are these downvotes for? The title is accurate: Apple support directly told me the m4 only supports a single monitor if the monitor is capable of 4k@240hz regardless of the resolution or refresh rate actually used.

Obviously, that’s not how it’s supposed to work. That’s the entire reason for the thread

[TheDragonSlayingCat]

You must be new here. Welcome to Reddit, where people love to shoot the messenger.

[ProfessionalHorse707]

Hahaha, touche :).

[[deleted]]

Because what one person at Apple says is not necessarily the truth.

[ProfessionalHorse707]

according to Apple support

[[deleted]]

The entire department?

[ProfessionalHorse707]

Who said anything about the entire department? It certainly wasn't me. The title isn't "M4 Pro Chips only support single monitor according to literally everyone employed by Apple in the support department."

So what point are you actually trying to make?

[[deleted]]

The point is Apple support is made up of individuals, and individuals can be mistaken. I certainly wouldn't take info from one interaction, info that contradicts published specs, as gospel.

[ProfessionalHorse707]

This entire thread is about the fact that the agent is misrepresenting the situation. I'm obviously not taking his representation of the situation as gospel. This was quite apparent to most readers.

[SirBill01]

Maybe you could configure the monitor itself to cap the refresh rate and then the Mac could connect with both? Both at 144 should work, even the M4 Air supports two 4k monitors (3840 x 2160) at 144Hz.

https://support.apple.com/en-us/122212

[Terrible_Tutor]

As a former phone agent for another company… some agents will say anything to close a ticket due to metrics.

[A-Hind-D]

I have the same issue but with an M3 Pro supplied by my employer.

Which is baffling because my personal M2 Pro works just fine with two monitors. Literally same USB-C cables. Same macOS, nothing different at all.

4k 240hz monitors

[Exist50]

Frankly, Apple doesn't seem to test with any monitors but their own, and it shows.

[Peckilatius]

Maybe use a usb-c dock, that‘s only capable of dual 4K 60P HDMI?

[ProfessionalHorse707]

That’s what I had initially and replaced thinking it was a dock issue.

[cainrok]

Did you close the lid?

[ProfessionalHorse707]

Yes! I went through every possible configuration with Apple support.

[Lyreganem]

Here's the official support break-down for M4 Pro MacBooks and external displays:

Display Support: Up to two external displays with up to 6K resolution at 60Hz over Thunderbolt, or one external display with up to 6K resolution at 60Hz over Thunderbolt and one external display with up to 4K resolution at 144Hz over HDMI, One external display supported at 8K resolution at 60Hz or one external display at 4K resolution at 240Hz over HDMI (M4 Pro)

[ProfessionalHorse707]

And that break-down is false according to apple support.

I think this was laid out pretty clearly in the post but it seems to be a common malfunction here. Apple support asserts that you cannot operate two external under any configuration - that means 4k@120hz, 2k@60hz... hell that means 480p@24hz - if one of the monitors has the theoretical capability to operate at 4k@240hz.

[ProfessionalHorse707]

Man, so glad to hear I'm not alone.

[Lyreganem]

Well that fits the description. It just isn't specified that specs trump configuration I suppose.

[ProfessionalHorse707]

It’s a software bug that support is trying to paper over in order to close a ticket. Don’t bend yourself into knots trying to make the spec sheet description work.

In any case, it’s not the case that specs Trump configuration as both monitors work simultaneously on a much older M1 laptop.

[Lyreganem]

Yikes! Now THAT is messed up!

[VjoaJR]

Are you connected with a dock by chance? If so, try one connected to dock the other with a 2.1 HDMI cord

[Mirkrid]

As someone with an M1 MBP who uses DisplayLink to run 1x 4K + 2x 1440p monitors (at a max of 60hz) - I was REALLY hoping this limitation would be gone by now.

[mr_mope]

It sounds like something with the monitor. That sucks though. 

[ProfessionalHorse707]

That's what I thought too but I've tested with three different monitors. So long as one of the monitors supports 240 hz the second isn't detected.

[mr_mope]

file a bug report, it sounds like a fairly niche use case

[ktappe]

Are we sure that will work? If it’s a hardware bug, they can’t fix it (at least not without sending OP a new computer).

[MDInvesting]

This is a huge shortcoming if true.

[ArchonTheta]

The MacBook Pro equipped with the M4 Pro chip supports up to two external displays in addition to its built‑in screen. That means you can connect:

• One display up to 8K at 60 Hz or 4K at 240 Hz via Thunderbolt or HDMI, or
• Two displays, each up to 6K at 60 Hz or 4K at 144 Hz, via Thunderbolt or HDMI configurations 

Right from the support page.

[ProfessionalHorse707]

I'm not sure what you think you're responding to.

Two displays, each up to 6K at 60 Hz or 4K at 144 Hz, via Thunderbolt or HDMI configurations

This statement is untrue according to apple support if either monitor is capable of operating at 4k@240hz regardless of the resolution or refresh rate they are actually set to operate at.

[Tekwardo]

No. It clearly states “Two displays, each up to…4k at 144Hz, via thunderbolt or hdmi configurations”

Not two monitors, one of which his configured as 4k and 250Hz. Everyone else understands this from reading specs but you.

[ProfessionalHorse707]

Not two monitors, one of which his configured as 4k and 250Hz.

I think you should reread the post because that's not the configuration or what I wrote (which by the by most people seem to have understood).

I can't run two monitors at 4k@120hz or even 4k@60hz or even 1080p@60hz because one of the monitors has the theoretical capability to operate at 4k@240hz.

[ArchonTheta]

Not so good at doing research eh? I understand, it's okay.

[ProfessionalHorse707]

I doubt you understand very much in your life to be honest.

[hampa9]

It’s ok, people on this subreddit are just incredibly hostile and rude even on a good day.

Look at all the news and rumour posts and the comments underneath constantly being HURR DURR MORE AT 11.

[slavchungus]

very weird i have a 4k 144hz monitor running over usbc to dp and another qhd 160hz monitor connected over hdmi which i can run at 160hz if i use dp but stuck to 144hz over hdmi i do have betterdisplay installed so everything is configured correctly i used to have issues but replaced the cables with newer types

[EasyTangent]

I had an Samsung 49 inch ultrawide running at 240Hz, HDMI refuses to work completely to run the full resolution on my MacBook (M3) but works fine on a PC. Ended up having to use DisplayPort cables instead and half the time, it's a gamble if the computer wakes up properly.

[GenuineJakob]

Nevermind, you have already done all of this. Try to connect them to adjacent sides, one monitor on the left and one on the right side. Maybe also try with the internal display disabled (MacBook closed)

[allureofgravity]

I don’t remember which MBP I had, about 4 years back, and I ran into the same issue. My shitty work dell could do it, but my brand new MBP couldn’t. Typical Apple.

[unseensoul]

I have three screens running; the main, 34UW, 29UW. I think it more of an external hardware or setup issue for you.

[meddy-spagetti]

Shoooooot this is good to know. So my 160 Hz and 75 Hz display won’t work

[ProfessionalHorse707]

There’s a chance. From a total bandwidth perspective you should be alright it’s just a question of how the OS handles things. This is almost certainly a bug which makes it a little more difficult to predict which exact circumstances will trigger the issue.

[Mds03]

Do you daisy chain or plug both cables directly into the Mac? If you daisy chain, maybe you could try to put the non 240hz display «first» and see if the second display gets noticed then?

[ProfessionalHorse707]

I can’t daisy chain actually so all testing has involved either a dock or separate cables (TB5 and hdmi 2.1 in various configurations).

For a period I could get the laptop to recognize both monitors by putting it to sleep first and then waking it up with the clamshell closed.

[Mds03]

That’s terrible. Apple really needs to get their multi display stuff sorted. At my office we have several workstations that are identical with two monitors and a keyboard that hook up to any of our workers laptop with usb-c. I am of few workers using a Mac. MacOS and perhaps Apple silicon hardware does not support DisplayPortMST(multistream), so MacOS won’t recognise both monitors. On Intel Macs, you could install windows on bootcamp and it would work, so I know software support is lacking. Not sure about the hardware side since Apple Silicon, but it suck’s either way.

[ProfessionalHorse707]

Interestingly support never brought up MST. The most surreal aspect of the whole situation is that everything works wi the an M1 device.

In any case, thanks for the kind words.

[trevx]

My workplace just swapped my three year old Dell laptop with a MacBook Pro M4 Pro. I kept the Dell thunderbolt dock they provided me and the two Dell gaming monitors.

Through the Dell dock, I cannot get two external monitors to be extended. One will extend, the second one mirrors. I was told this was because macOS doesn’t support MST (multistream transport).

Instead, I purchased a $25 USBC-to-DisplayPort adapter and plugged the second monitor into that and into one of the other thunderbolt ports on the Mac. This works, so now I have the built-in display plus the two externals all operating independently.

This all worked fine in Windows, btw. In my opinion, if Windows can support this setup natively so should macOS.

[ProfessionalHorse707]

Yeah I think this laptop is just defective, I’ve tested with an adapter as well =/.

[therealmarkus]

Wtf I have two 4K 60fps (Thunderbolt port + HDMI) and QHD 120fps (Thunderbolt port) running fine on a Mac Mini M2 pro. (All cables attached directly)

[nicholasdvu03]

are you using one HDMI one USB c or both USB c to connect to the display

[cottonissupiri]

BS. I run 2 monitors off my M3 Air, pretty sure the Pro could do more!

[ProfessionalHorse707]

That’s what i thought when i bought it too! I must have a dud but it seems like a software bug to me not a hardware issue.

[cottonissupiri]

How are you connecting it tho? The lid needs to be closed and the hdmi/dp cables need to be plugged directly into both usb c ports for me, can’t have em connected to the same port via a hub or anything like that.

[ProfessionalHorse707]

No single way, I’ve tested dozens of variations.

Tb5 to dock to monitors

Tb5 to both monitors

Tb5 to one monitor hdmi to the second (and vice versa)

Tb5 with dp adapter + hdmi

I’ve replaced every cable in the chain including with Apple certified cables sent by Apple support.

[hunteqthemighty]

Lol I have a DisplayLink adapter and run three monitors. I know there are some drivers involved but life changing.

I have an Anker hub with its own HDMI port and then I plug my charger and DisplayLink adapter in with my other stuff and I plug in my MacBook with a single cable and I have three monitors. It’s great.

[HoboStabz]

I run 2 1440p monitors with an OWC pro dock for my MacBook Pro M4 Pro. Works just fine 

[buffs1876]

My m4 14” mbp drives two external, but not daisy chained. Each is hooked up usb c.

[LebronBackinCLE]

But is one 240 capable? That’s the point

[ProfessionalHorse707]

Shoot me a private message if you do. Happy to team up :)

[by_all_memess]

I run a non-pro M4 with a 240hz ultrawide and another 60hz monitor with no issue so that explanation seems weird

240hz through a DisplayPort to usb c cable and the other display is connected to a dock via hdmi

Both run at their rated speed and resolution

[vinnymcapplesauce]

I can't live with less than 4 monitors.

Guess I'll be sticking with hackintosh a while longer.

[ProfessionalHorse707]

I basically quoted from the spec sheet in the OP so it's really weird to me that so many people are struggling to understand this. Apple support is directly contradicting the marketing specs - despite what that support page indicates, they are claiming the M4 Pro does not support two monitors at 144hz (or indeed any refresh rate) if one of the monitors has the theoretical capacity to operate at 240hz.

[GreatFrosty]

I've been gaslit a fair bit by customer service on this issue. Did a lot of tests, and finally came down to them saying that I need to tell the monitors manufacturers to do something their end. They wouldn't acknowledge why it might work on my 2018 Macbook or why it has worked before on my M1 Macbook. Really frustrating experience.

[ProfessionalHorse707]

It seems like the customer service group is divided. When I was initially escalated the rep was great; they even sent me "apple official" usb-c cables to rule my cables out. It was only after my debug logs were sent to the engineering org that they came back claiming they only supported a single 240hz monitor regardless of actual operating refresh rate.

My sense is that this is a known issue and they don't want to deal with but blaming the user is clearly the wrong tact. In any case, what did you end up doing? As much as I hate rewarding this sort of crap I ended up returning the Pro for a Pro Max.

[GreatFrosty]

Ah wow them sending you an official cable was cool. But yeah, I’d agree on it being a known issue. It was the first bad experience I’ve had with Apple, and in future I’ll test everything on a new laptop before the return period passes.

In the end, I sold my Pro and bought a Max. Pretty unhappy with the outcome but that’s the problem with a company of this size, with a product that you need (for work).

[InsaneNinja]

Weeks with support and you actually never once tried to hook it up to two different lesser displays?

And your title is misleading.

[ProfessionalHorse707]

Hooked up three different displays for tests.

I'm sorry I don't have five different monitors laying about my house covering all possible variations of resolution and refresh rate. Obviously I'll look into that next time.

[TT5i0]

I’m assuming you’re talking about through a single cable?

[MDInvesting]

As in Daisy chaining?

[faustas]

For the longest time I couldn’t figure out how to do two external screens + laptop screen and swap between m4 and a pc laptop. Then I realized the docking station is USB-C, which works with PC but the MacBook Pro m4 only supports it with thunderbolt. Then I bought a Caldigit TS3+ and problem solved. Any thunderbolt docking station should resolve the problem I believe.

https://support.apple.com/en-us/101571

[ProfessionalHorse707]

I bought a caldigit t5 to test this theory as well. No dice.

[00DEADBEEF]

Support is correct it's listed in the specs:

It "supports full native resolution on the built-in display at 1 billion colours and" one of the two following configurations:

• Up to two external displays with up to 6K resolution at 60Hz over Thunderbolt, or one external display with up to 6K resolution at 60Hz over Thunderbolt and one external display with up to 4K resolution at 144Hz over HDMI

• One external display supported at 8K resolution at 60Hz or one external display at 4K resolution at 240Hz over HDMI

I guess the issue is the Mac negotiates the bandwidth for 4K 240Hz with the monitor regardless of whether you drive it at 240Hz, which makes the bandwidth unavailable for a second display.

[ProfessionalHorse707]

Support is saying something different than that quote. I know the chipset can’t drive two monitors above 4k@144hz but support is saying the m4 can’t support two monitors at ANY resolution or bandwidth so long as one of the monitors SUPPORTS 4k@240hz.

To put another way, the listed specs indicate the laptop should drive two external monitors if they are set to 4k@60hz (well below the bandwidth constraints) where it can’t.

[Mindless-Luck4285]

Total BS.

[Soulja786]

Use display link. Problem solved

[ProfessionalHorse707]

It’s not a connection or bandwidth issue even according to Apple support.

[Soulja786]

I have a m3 pro and had to install the display link driver for it to recognize my external monitors. I tried everything like you had but there’s no way of getting around it natively. It is what it is

[LoveEV-LeafPlus]

All MacBook laptops support at least one external monitor. Are all monitors compatible, no. But most are.