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In addition to the new iMac with the 10-core M4 chip being the first-ever Mac with support for up to an 8K external display at 120Hz, the computer also supports up to two 6K external displays at 60Hz. That's a very notable upgrade, as lower-end Apple silicon Macs like the MacBook Air, entry-level MacBook Pro, and previous iMac models have mostly been limited to a single external display, at least on an official basis.

hero-banner-displays.jpg

Two exceptions are the MacBook Air and 14-inch MacBook Pro models with the M3 chip, which support up to two external displays, but only when the laptop's lid is closed. Another exception is the Mac mini, which has an HDMI port for connecting a second display. DisplayLink adapters have also been a viable solution for multiple external displays ever since the first Apple silicon Macs with the M1 chip launched in 2020.

But the 10-core M4 chip is notable in that it will bring proper support for two external displays to more lower-end Macs for the first time since Apple silicon launched, without any special tricks required. No more DisplayLink adapters, and no needing to have the MacBook's lid closed. That's a significant, long-awaited advancement for Apple silicon.

Higher-end Apple silicon Macs have supported multiple external displays since the MacBook Pro models with M1 Pro and M1 Max chips launched in 2021.

Apple is expected to announce a new entry-level 14-inch MacBook Pro with the 10-core M4 chip this week, and an alleged leak already confirmed that the laptop will support two external displays with the lid open. Next year, the M4 chip should expand to the MacBook Air, and 10-core configurations should likewise support two external displays.

The new iMac is available to pre-order now, and it launches on Friday, November 8.

Article Link: Lower-End Apple Silicon Macs With 10-Core M4 Chip to Fully Support Two External Displays
 
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Hope this feature comes to the M4 Air. The ability to have 2x external displays (I have 2 Apple Studio displays) plus my laptop screen, would make it perfect for my home office setup.

The M2 Air handles my business workflow and 4K editing needs just fine. The external display issue is the only thing that kept me using the Pro over the M2 Air. I just sold the M2 Air to get an M3 Air so now I'll be waiting until the M4 Air comes out.

Fingers crossed. This is exciting!
 
Still no DisplayPort MST though right? So even with a quality TB4 dock, at least one of your displays is native Thunderbolt (not DisplayPort) your dock will only support 1 display.

What that means is that native single cable docking to two external displays is impossible.

The only way to drive two displays from one cable is to use DisplayLink (oof) or have at least one Thunderbolt Display. The TB display limitation really impacts the amount of displays you can pick from.

Apple has supported DisplayPort DSC for a long time, but has never supported MST which is terrible.
 
Meanwhile, my M2 Pro Mac mini that used to get 144hz on 3360x1890 could only do 120hz with macOS 15.0 & 15.0.1. When I updated to 15.1 earlier, I noticed that it dropped to 100hz for the same scaling option. Somewhere along the way in macOS 14, the external monitor (Dell G3223Q) started turning on when I wake it, going to a blank screen immediately after and then taking around 10s to come back on with the login page. It still happens for waking (before entering password) & rebooting (after entering password).

Hope they work on their external monitor support properly before trying to add the ability for more external monitors.
 
Still no DisplayPort MST though right? So even with a quality TB4 dock, at least one of your displays is native Thunderbolt (not DisplayPort) your dock will only support 1 display.

What that means is that native single cable docking to two external displays is impossible.

The only way to drive two displays from one cable is to use DisplayLink (oof) or have at least one Thunderbolt Display. The TB display limitation really impacts the amount of displays you can pick from.

Apple has supported DisplayPort DSC for a long time, but has never supported MST which is terrible.

Not sure I follow this. My current M1 Pro connects to two Apple Studio displays via a single cable routed through my CalDigit TS4. The displays aren't daisy-chained - they each connect separately to the dock. However, I only run one cable from the M1Pro into the dock, which carries 2x 5K @60Hz just fine.

Do you think that might not work with M4?
 
Meanwhile, my M2 Pro Mac mini that used to get 144hz on 3360x1890 could only do 120hz with macOS 15.0 & 15.0.1. When I updated to 15.1 earlier, I noticed that it dropped to 100hz for the same scaling option. Somewhere along the way in macOS 14, the external monitor (Dell G3223Q) started turning on when I wake it, going to a blank screen immediately after and then taking around 10s to come back on with the login page. It still happens for waking (before entering password) & rebooting (after entering password).

Hope they work on their external monitor support properly before trying to add the ability for more external monitors.
What does your cabling situation look like?

I'm on an M2 Pro and can drive my 3840x2160 display at 240hz HDR no problems. I'm using USB-C though.
 
Not sure I follow this. My current M1 Pro connects to two Apple Studio displays via a single cable routed through my CalDigit TS4. The displays aren't daisy-chained - they each connect separately to the dock. However, I only run one cable from the M1Pro into the dock, which carries 2x 5K @60Hz just fine.

Do you think that might not work with M4?
Studio Displays are one of the only Thunderbolt display options on the market. You'll be fine.

The issue is that you can't send two non-Thunderbolt display signals to a dock over USB-C or TB4.
 
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The lower-end M1 Mac Mini has always supported two external displays. I imagine the new M4 Mini will support up to 3, with perhaps the M4 Pro Mini supporting 4.
The M1 has always supported two displays, but one of them was always hard-wired to the internal display for all of the Macs that have internal displays. The correct way of thinking about it is that the iMac now supports three displays with the base M4 chip.

Random side note, the M1 mini only supports two displays if you use the Thunderbolt and HDMI ports at the same time. The M2 mini on the base model removes this requirement, a single Thunderbolt port can drive two displays (and thus be called Thunderbolt 4 as that's a requirement).

Given that the new iMac can support Thunderbolt on all four USB-C ports I'm guessing Apple gave the M4 some pretty substantial I/O upgrades.
 
I use 2 external displays and the 2020 MacBook Air M1 screen using display link. Works perfectly. Albeit not at 8K!
 
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If one disconnects the iMac internal display ribbon cable then would one be able to use two external 1024x768 15" LCDs?
 
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No 27 inch or 32 inch iMac - My iMac is 5 years old. I think they have decided not to go big with the displays.
Apple literally said last year with the M3 iMac launch that they felt 24" was the sweet spot between the 21" and 27" models and that they had no intention of making a larger iMac. Given that Apple rarely comments on future products I would call that a big signal to stop waiting.
 
Now if you could use the thing as a monitor for your MacBook…
Screen Sharing between Apple Silicon devices actually rocks. It supports HDR and is surprisingly fast especially over ethernet.

Would native video in on the iMac be better? Absolutely, but screen sharing works phenomenally well.
 
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If one disconnects the iMac internal display ribbon cable then would one be able to use two external 1024x768 15" LCDs?

Yes, yes you would, but you would also be able to without disconnecting the internal display, as in, that's completely optional.
 
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