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The apple monitor limitations on the M series chips are so stupid. What's "pro" about using 2 monitors.. that's been a thing for decades on basic intel machines.
 
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I'm wondering who's actually running dual-external display with the lid closed?

You lose the keyboard, Touch ID, webcam, speakers, trackpad, and obviously the Retina display. So yes, technically, the M3 supports dual external display. But in practical terms, it really doesn't.
*Raises hand*

My M3 Max 14" MBP apparently never got the message because I've been using it with an Apple Studio Display and an LG 5K with the Mac docked and the lid closed. Only thing I miss is the TouchID, but that could be rectified with a new keyboard, but I'm not going to give up my mechanical switch keyboard for that. And both monitors have cameras.
 
Again what is all the fuss. I can get 2x4k at 120mhz connected to my MacBook Pro M1 and M3 14.

Here is the demo for the unbelievers …

 
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Tell that to my M3 Max MBP in clamshell that reaches 53 degrees celsius connected to 1 1440p monitor, 1 4K monitor and watching a Twitch stream at 1080p on the 1440.

I'm really beginning to think there's something wrong with my Mac. A 16" MBP on low load [as specified above] should be at least hovering at 35 degrees.
I’m curious what computer you are comparing to and why you think 53° Celsius is high. Anything under 70° is quite cool in my opinion.
 
Ahhh yes, the software locked feature that legit made the MBA better than a “pro” model
Ahhh yes pesky software requiring engineers to do work to resolve issues and enable things to work as desired. "But it's so eaaaassssyyyy! Why can't it just woooooork!"

Yeah everything is easy, or a conspiracy, to people far removed from the problem domain. Rule #1 of software -- nothing is easy. Rule #2 -- "just" is a four-letter word. "Just...have it do this. Just...make it do that. "Just...a simple change, right?"
 
We upgraded our standard MacBook to the M3 Pro/Max and eliminated the issue, that’s not laziness, it’s being proactive. Our users may be upgrading from an Intel MacBook that can support multiple displays and be confused as to why the “upgrade” no longer supports that feature. Maybe your attitude towards your IT department is why you had issues with them..
Ha! No. I replaced our IT manager and the entire company was thankful - including the IT group.
 
Surely you jest?

I run my MBP probably 80% in clamshell at home with 2 monitors and externals versus 20% while traveling as a laptop with my iPad as the 2nd monitor.

Why would I want to use the comparatively tiny screen, keyboard, trackpad while at home versus 2 27" monitors with a full size KB and mouse? And my desktop speakers are way better too.
Same here. I have my Mac in clamshell when I WFH. I have an apple external keyboard with Touch ID so I don’t lose that. I use a logic camera that sits atop my *matching* 24” 4k monitors (LG). The only time I open the MBP is when I travel. I like my screens to match.
 
How to make people happy: take something away from them and then give it back.
My Early 2013 MBP could support 3 external displays and the internal one.
Ten years later Apple announces a big feature: their brand new MacBook Pro can support two external displays, but only if you close the lid!
 
I'm wondering who's actually running dual-external display with the lid closed?

You lose the keyboard, Touch ID, webcam, speakers, trackpad, and obviously the Retina display. So yes, technically, the M3 supports dual external display. But in practical terms, it really doesn't.
I am...because I use a full size keyboard, mouse, and two 4k displays (27" and 33") in clamshell mode.
 
Don’t understand what is the novelty.

Been running dual displays in clamshell mode since Macbook M1 Pro. Yes, running two cables out of the USB-C ports.

What is new here?
Again what is all the fuss. I can get 2x4k at 120mhz connected to my MacBook Pro M1 and M3 14.

Here is the demo for the unbelievers …

This update is only for the base M3 chip. You didn't show us what chip you're using, but I'm guessing it's the Pro or Max since you're running three displays.

The base M1/M2/M3 chips can only run one external display regardless if the lid is open or shut. This update makes it so that the base M3 14" MBP can run two external displays when in clamshell mode.

The M1/M2/M3 Pro chips can run up to two external displays, plus the built-in one.

The M1/M2/M3 Max chips can run up to four external displays, plus the built-in one.
 
So is this a case of you have to have an M3 MacBook to do this? It wouldn’t work on my M1 Max MacBook Pro? Like it’s not technically possible? Or Apple just being Apple?
 
It would be useful to keep the lid open for the camera and Touch ID.

But it would be too complicated for Apple to let users disable the internal display when the lid is open.

I use a DisplayLink docking station with my M1 MBP and two external displays and have to mirror one of the displays to the internal display and then reduce the brightness of the internal display to zero in order to emulate a disabled internal display and still be able to use the camera, the Touch ID and the Touch Bar on the MacBook Pro.
Every Windows laptop has a dedicated key on the keyboard to switch to this mode without dumb workarounds.
Pretty certain some older Intel MacBook Airs did exactly this.

If you own the software and hardware vertically, it’s a choice you’ve chosen to make. Though their timing with the M3 Air did make things look odd.
 
I’m curious what computer you are comparing to and why you think 53° Celsius is high. Anything under 70° is quite cool in my opinion.

Funny enough I'm comparing to my 14" M3 Pro. Both have TG pro with identical fan curve installed, however the 14" manages to kick the fans keeping the Mac at 40°C, whereas the 16" kicks in above 50°C.

**Update**
After using my Mac last night, temps stayed at 37°C. It could have been the rooms ambient temp. We are in the summer months. Even with Central Air w/AC on my room is a comfortable 76°F.
 
So odd that these "features" are news. I can connect my personal 14" M1 Macbook Pro to my work Dell USB C dock to run 3 1440p monitors (2 27" and a 32".) I had to download DisplayLink software to enable it, but it didn't cost anything and works perfectly.
 
I'm wondering who's actually running dual-external display with the lid closed?

You lose the keyboard, Touch ID, webcam, speakers, trackpad, and obviously the Retina display. So yes, technically, the M3 supports dual external display. But in practical terms, it really doesn't.

And slowly cooks itself to death.

Apple doesn't care, because it rarely happens while it's still in warranty. But the fools who do it better hope they've got the money to replace what would have been a good computer for quite a few more years.
 
It's not being able to use the built-in monitor when external monitors are connected.

View attachment 2401246

Sure, you can buy a separate Touch ID keyboard, speakers, webcam, etc. But it seems a waste when an external Magic Keyboard is exactly the same size and layout.

The difference between M3 and M3 Pro is only $200. Ignoring the performance bump, being able to use 3 monitors simultaneously is a big benefit.

Clamshell mode on M3 MBA can reduce performance by up to 50% due to heat.

Yep. You're guaranteeing thermal throttling running with the screen closed. But unfortunately it's not enough thermal throttling, it's still going to kill the computer.

I wish Macs had a "hours running with the screen closed" counter so people would know not to buy used Macs that these fools abuse.
 
So odd that these "features" are news. I can connect my personal 14" M1 Macbook Pro to my work Dell USB C dock to run 3 1440p monitors (2 27" and a 32".) I had to download DisplayLink software to enable it, but it didn't cost anything and works perfectly.
It's great that it works "perfectly" for you, but it's not a solution for everyone. You must not have ran into any of the limitations of DisplayLink.

DisplayLink displays are virtual displays rendered in RAM rather than actual dedicated display buffers on the chip, so it uses up RAM that other apps could be using. (Not a huge deal if you have a lot of RAM.) It can have laginess or compression artifacts on the screen, especially when using 4K and/or displaying fast moving content. DisplayLink doesn't work with content protected streaming services, such as Netflix, Hulu, Disney+, etc. You need to disconnect those displays, otherwise you'll see a black box instead of video. It also doesn't work with Night Shift or True Tone. MacOS updates have been known to break DisplayLink in the past...and have to wait until Synaptics/DisplayLink pushes out a fix.
 
Yep. You're guaranteeing thermal throttling running with the screen closed. But unfortunately it's not enough thermal throttling, it's still going to kill the computer.

reference please. and how many usage hours are we talking?

I would love to see some references for these claims, won't hold my breath though.

Anecdotally, my MBP has been sitting at 43C all day in clamshell, opened it up for an hour and saw 44-45C, I assume because the screen was on.

What I will offer on the topic is this, when in clamshell I use a stand and always have the vents up, click the link in post #23 to see it. I do see many people who have the vents down so that the Apple logo is oriented the correct way but why fight the hot air and potentially block your vents? I never hear my fans.

And to be fair, sustained, processor intensive jobs are not common in my workflow. The only time I think I ever heard fans was when ripping DVDs but honestly I can't remember if that was my 2017 MBP or this one, I haven't done it in a couple of years.
 
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I would love to see some references for these claims, won't hold my breath though.

I know what you mean... not the first time I have asked because I am genuinely interested. it is always anecdotal 'trust me I know.' Maybe in the days of intel because those chips DID routinely get hot. But with apple silicon, the largest performance hit I have seen measured as a function of extreme stress was 10% and the fans turn on so rarely in actual use. Just don't see it being a problem. Like you, clamshell or not, the temperature remains low. but hey, maybe someone has a reference to prove their assertion. might happen.
 
So odd that these "features" are news. I can connect my personal 14" M1 Macbook Pro to my work Dell USB C dock to run 3 1440p monitors (2 27" and a 32".) I had to download DisplayLink software to enable it, but it didn't cost anything and works perfectly.
Not really that odd, as it is news because it is new specifically for the M3 MacBook Pro 14”, and there was no M1 MacBook Pro 14”, only M1 Pro and M1 Max variants.

The M3 MacBook Pro 14” is the model that effectively replaced the M1 and M2 MacBook Pro 13”, and though it looks very much like the earlier generation 14”, it has/had different features from the M# Pro and M# Max CPU MacBook Pro 14” models.

This is indeed not news for the M1-M3 Pro or Max MacBook Pro 14”, as was noted in the article.
 
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So is this a case of you have to have an M3 MacBook to do this? It wouldn’t work on my M1 Max MacBook Pro? Like it’s not technically possible? Or Apple just being Apple?
Do you really want Apple to lower the number of external screens they have always allowed you to 2, and only allow that with the screen closed? You already get 4 external screens on the M1 Max CPU, I believe, plus the internal screen. (2 external screens with the M1 Pro CPU.)

This just adds the dual external screen support to a lower end base M3 CPU model (not Max or Pro CPU) that didn’t already include more.

As for Apple just being Apple, many of the comments on this thread make me understand why Apple wouldn’t want to enable any new features with updates, since it just seems to confuse some users.
 
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