iMac displays: can a 'modern…' 24" model drive an 'ancient…' 27" screen?

This might sound like an unbelievably naive Question and still would it be impossible, or problematic, to rip the guts out of a modern 24" iMac, and re-house them in an 'ancient…' 27" case, in order to use the 27" screen?

iMac 27″

Posted on May 28, 2025 1:03 PM

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Posted on May 28, 2025 1:27 PM

No you can not mix and match like that, because everything including the connections are different.


If you have a 24" iMac, you can connect a 27" aftermarket external display to it.

Connect an external display to your iMac - Apple Support


If you get a new Mac mini, you can connect 1 or 2 27" aftermarket external displays to it.

Connect a display to Mac mini - Apple Support


35 replies
Question marked as Top-ranking reply

May 28, 2025 1:27 PM in response to Robbie Goodwin

No you can not mix and match like that, because everything including the connections are different.


If you have a 24" iMac, you can connect a 27" aftermarket external display to it.

Connect an external display to your iMac - Apple Support


If you get a new Mac mini, you can connect 1 or 2 27" aftermarket external displays to it.

Connect a display to Mac mini - Apple Support


Jun 1, 2025 11:00 AM in response to Robbie Goodwin

Robbie Goodwin wrote:

This might sound like an unbelievably naive Question and still would it be impossible, or problematic, to rip the guts out of a modern 24" iMac, and re-house them in an 'ancient…' 27" case, in order to use the 27" screen?

The bus and ports would be different and not compatible. It just can't be done. As for the Mini cluttering up the desk here is my Mini under my 32" monitor:



The screen real estate is larger and the price is right.

May 31, 2025 11:13 AM in response to rkaufmann87

rkaufmann87 wrote:

Well there is no other choice. It makes no sense to attempt a Frankenstein Mac that will:

A) Be expensive
B) Likely fail due to hardware hacks
C) Void any and all warranties

particularly when there are very viable solutions, a Mac mini and display which will be:

A) Less expensive than a Frankenstein Mac.
B) Dead reliable
C) Have a 1 year Apple warranty and be eligible for AppleCare.

If you still are not convinced, ummmmm okay it's totally up to you to decide your fate.


May 31, 2025 4:17 PM in response to Robbie Goodwin

Yes the phrasing was helpful. As far as technicalities you would need to manufacture custom components, do micro soldering , develop your own adapters and not to mention modifications to Mac OS to accommodate all of the hacks that would be needed. This alone would not be possible unless Apple opens Mac OS to be open source which is not likely.


We are simply attempting to point out that while your idea may have merits it is not viable. If what you want is not available from Apple then suggest it at www.apple.com/feedback or buy a MM as has been suggested multiple times.

May 29, 2025 3:08 PM in response to Robbie Goodwin

Well there is no other choice. It makes no sense to attempt a Frankenstein Mac that will:


A) Be expensive

B) Likely fail due to hardware hacks

C) Void any and all warranties


particularly when there are very viable solutions, a Mac mini and display which will be:


A) Less expensive than a Frankenstein Mac.

B) Dead reliable

C) Have a 1 year Apple warranty and be eligible for AppleCare.


If you still are not convinced, ummmmm okay it's totally up to you to decide your fate.

Jun 25, 2025 12:42 PM in response to Robbie Goodwin

Robbie Goodwin wrote:

Thanks, den.thed

Sadly, I saw nothing in those links, nor their further links, to suggest whether I'd get a 27" picture, or a 24" picture magnified to fill a 27" screen.

Will you clarify?


If you use a 27" external display, you get a 27" picture.


The resolution of that display will make a difference. 27" displays are available with resolutions of 1920x1080, 2560x1440, 3840x2160, and 5120x2880. You choose one with a resolution of 1920x1080, you're going to get oversized text and objects with coarse detail, and only the amount of workspace typical of a 24" monitor.


I suppose that in that sense, a 27" 1920x1080 display might have "a 24" picture magnified to full a 27" screen." Technically, it would still be a 27" picture – just a lower-quality one than other monitors might have delivered.

May 31, 2025 4:13 PM in response to Robbie Goodwin

If you have training in electrical and hardware engineering, you should be able to research the difficulties involved for yourself. (At least to a much greater extent than is obvious from your posts here.)


if you do not have an engineering background, encouraging you to engage in the project would be much like encouraging a new teenage driver to tear down and rebuild their engine and transmission, or encouraging someone with no medical training to perform open heart surgery.


So I’m not sure what problem you have with rkaufmann87’s post, other than the fact that it wasn’t the answer you were hoping for.


Personally, I think you really ought to consider getting a M4 Mac mini, M4 Pro Mac mini, or M4 Max Mac Studio and pairing it with a 27” display. If your budget is large enough, it could even be a 5K Apple or third-party display - and a M4 or M4 Pro Mac mini sitting next to it would not take up much room on your desk.

Jun 25, 2025 11:07 AM in response to Robbie Goodwin

Robbie Goodwin wrote:

Thanks, den.thed

Sadly, I saw nothing in those links, nor their further links, to suggest whether I'd get a 27" picture, or a 24" picture magnified to fill a 27" screen.

Will you clarify?

Sorry, that makes absolutely no sense.


If the physical dimensions of the display are 27". So you get an image that is 27" in diagonal size. The physical dimensions of the iMac's display have no bearing on the image size the external display will show whatsoever. Though not sure why this is a concern.


If you perhaps are referring to the image resolution, totally unrelated to physical dimensions, you can set that to whatever the external display supports, again it is not restricted by the iMac's display's max resolution in any way.

Physical display size does not affect the actual resolution you will see on it either.

You can get 4K on a 24" display and you can get the same 4K on a 75" TV. It will just look larger on a 75" TV because it's physically larger, but will not be stretched or distorted in any way.


The external display could also use a lager resolution, up to 6K, independently of what the built-in screen can display (4.5K).




Jun 25, 2025 2:53 PM in response to Robbie Goodwin

Robbie Goodwin wrote:

No, it's you who makes no sense.

Even in proper English, every school-child should understand 'If the physical dimensions of the display are 27", you get an image that is 27" in diagonal size…'

Will you say why it's difficult to accept, that's as irrelevant as it is true?

Because that's not the way displays work. They don't stretch the image size to fit themselves. As I said, a 27" display will provide a 27" image diagonally period. The question does not make sense as posed, because it does not apply to how displays work.


Will you say whether, on your scale of 24 - 27 - any 24" iMac can put out a picture of the same scale or resolution, and fill a 27" screen?

Not the way displays work. You don't have more digital area to fill just because it's a larger display. As was mentioned you can have a 24" display and a 27" display that have the same exact resolution (for example 1900x1080, its just one screen is physically larger than the other, but the amount of actual pixels is the same on both. On the 27" displays the pixels will be larger though.


The physical size of the screen has no relation to the image it displays. It just means the image is larger in and of itself in relation to another image because the actual display is larger. But has no effect on the image resolution or digital dimensions.


It just means it will look larger because it's a large canvas. but there is no stretching there is no alteration. Asking that question is meaningless because displays do not modify the image depending on their size.


Jun 25, 2025 3:44 PM in response to Robbie Goodwin

Robbie Goodwin wrote:

My iMac's 27" display does offer your 2560 x 1440 but not 1920 x 1080, 2560 x 1440, 3840 x 2160. Does that say anything about your assertion?


It says that you have an 27" iMac released between Late 2009 and Late 2013, inclusive. Starting in late 2014, all 27" iMacs and iMac Pros had 5k (5120x2880) pixel panels.


The normal way to run those was not in 5120x2880 mode, but in Retina "like 2560x1440" mode, where

  • Applications sized things "as if" the display had a resolution of 2560x1440 pixels
  • Retina-aware applications could fill in photo areas, and draw letters, with 2x as many pixels in each direction as the "Displays Preferences" setting implied. I.e., at a (2x2560)x(2x1440) or 5120x2880 pixel level of detail.

This resulted in a big increase in sharpness while keeping text and objects from shrinking into obscurity.


But with 5K resolution, it was feasible to crank the "UI looks like" resolution up a notch, to cram, say, as much text as would "normally" fit on a 32" 6K display onto a 27" 5K screen – at the cost of making the text smaller. My Mac gives me the option to do that with a 4K display.

Jun 26, 2025 5:07 PM in response to Robbie Goodwin

Robbie Goodwin wrote:

Assuming System Preferences on the latest OS uses the same terminology as my 10.13.6 High Sierra, what Resolution Scales should be available on a late-model 24" iMac?


There were no 24" iMacs that could run High Sierra. Apple released one 24" iMac in September 2006 that could not run anything higher than Mac OS X 10.7.5 Lion. They didn't return to the 24" size until they released the first Apple Silicon iMac in May 2021.


That ancient 24" Intel iMac had a panel with a resolution of 1920x1200 pixels. Given that combination of screen size and resolution, the display would have had about 94 PPI. Text would have been a comfortable size with the Displays Preferences resolution set to the full LCD panel resolution, and there would have been no need for the yet-to-be invented Retina scaling. No increased sharpness of text or photo areas, either.


The M1, M2, and M4 iMacs have a LCD panel resolution of 4480 x 2520 pixels, and a pixel density of about 218 PPI. If applications treated all of the extra pixels as extra "workspace", each piece of text on on the current 24" screens would only be about 43% as physically wide and 43% as physically tall as on the screen of that ancient iMac. Text would "shrink" into an area which was physically only about 18.6% of the size of the area on the ancient 24" screen. The human eye is sensitive to the physical area of images projected onto the human retina, which in turn is a function of physical size, and of viewing distance. This is the reason why people usually run the built-in screens on the M1, M2, and M4 iMacs in a Retina scaling mode.


Apple does not have user documentation that lists all of the Displays {Preferences/Settings} resolution settings available on every Mac model. For the M1, M2, and M4 iMacs, I would assume that in the simplified (icon) view, "More Space" means "non-Retina 4480 x 2520", and that one of the other choices is "Retina like 2240 x 1260." My guess is that all of the choices except "More Space" (full panel resolution) use Retina scaling, so as to take advantage of the panel resolution, rather than merely drawing at a "(low resolution)".


As for iMacs that could run High Sierra, there were

  • 21.5" iMacs with 1920x1080 pixel screens (~102.5 PPI)
  • 21.5" Retina 4K iMacs with 4096x2304 pixel screens (~218.5 PPI)
  • 27" Macs with 2560x1440 pixel screens (~108.8 PPI)
  • 27" Retina 5K iMacs with 5120x2880 pixel screens (~217.6 PPI)


I would guess that when running High Sierra, which options you saw in Displays Settings would depend on which of these four types of screens your Mac had.

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iMac displays: can a 'modern…' 24" model drive an 'ancient…' 27" screen?

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