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zoran

macrumors 601
Original poster
Jun 30, 2005
4,721
125
I’m looking for a 27” 4K iMac, how can I know that it’s the 4K one? What can I ask the seller for, so I will be certain that it’s the one?
 

zoran

macrumors 601
Original poster
Jun 30, 2005
4,721
125
It’s the 2011 27-inch iMac. LED-backlit glossy widescreen, with a resolution: 2560 by 1440 pixels.
 

redheeler

macrumors G3
Oct 17, 2014
8,419
8,841
Colorado, USA
Any iMac before 2014 is not 5K (or 4K). The number is a rounded version of the horizontal resolution, e.g. 2560x1440 is 2.5K because 2,560 rounds to 2.5K.
 

zoran

macrumors 601
Original poster
Jun 30, 2005
4,721
125
Is there something special regarding the 2011 27" iMac?
 

DeltaMac

macrumors G5
Jul 30, 2003
13,476
4,410
Delaware
Couple of "special somethings", maybe...
The 2011 is the last iMac where you can open up the case without slicing through tape.
The Mid 2011 iMac the first iMac sold only with quad-core processors.
It's the first iMac sold with Thunderbolt
Mid 2011 iMac is the last iMac sold with USB 2.0 (not sure if that's really special. Just something to remember when using external storage.)
There could be other "special" things about the 2011 that I did not consider special.

In regards to your opening question: Retina 5K iMacs were sold from late 2014 on, so you would look for iMac 27-inch, from late 2014 on. The 21.5-inch Retina iMac, with a smaller display, was sold starting 1 year after the 5K, with that smaller screen called a "4K"
So, if it is older than a 2014 model, then it can't be a Retina screen.
 
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DeltaMac

macrumors G5
Jul 30, 2003
13,476
4,410
Delaware
Well, yes, there's that... Tough times in general for Macs 2009 to 2011.
I have a 2010, that I use for special purposes (doing factory resets/clearing passwords on various non-Apple phones, etc.) It occasionally acts up, and I have decided it is the graphics card. So far, I can get it to continue to work, but at some point, it will be gone, I think.
 

zoran

macrumors 601
Original poster
Jun 30, 2005
4,721
125
I cant figure out why JuicyCrumb have decided to make a board for the 2011 iMac and nothing for other iMacs.
Also... #DeltaMac you are very lucky that your 2010 is still working :-D
 

DeltaMac

macrumors G5
Jul 30, 2003
13,476
4,410
Delaware
I wonder if it is related to Thunderbolt, which the 2011 has.
And, newer iMacs, being thinner, may not have the internal space for that big adapter card - and space for an m1 mini.
So, the 2011 may be the only one that has the needed connections, and also has sufficient internal space.
Just guessing on this, as I am not really sure how the JuicyCrumb card is installed.
 
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tothemoonsands

macrumors 6502a
Jun 14, 2018
518
1,098
You are looking to buy?
I’d be willing to sell my 2020 loaded iMac 27” 5k. Would need to ship within USA only due to costs.

Top end 10 core i9, top end 5700XT GPU, 2 TB SSD, 64 GB RAM.
 
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zoran

macrumors 601
Original poster
Jun 30, 2005
4,721
125
If the 27” 2011 iMac doesn’t have a 5K display, then would it should have the same 2K display as the 2010 model?
#tothemoonsands No thanks
 
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Fishrrman

macrumors Penryn
Feb 20, 2009
28,391
12,502
DO NOT BUY a 2011 iMac.
They seem to have a much-larger-than-normal problem with the internal dedicated GPU's.

Get something more recent.
I'd suggest 2017, 2019, or 2020.
 

theluggage

macrumors 604
Jul 29, 2011
7,510
7,411
You mean they are 2K?
The "4k, 5k" notation only really started with 4k displays - and even today its not a robust notation: "4k" is commonly used to mean UHD which is actually 3840x2160 - although the only 4k Macs were post-2015 21.5" models that actually had "true" 4k displays with 4096 horizontal pixels. Also some non-Apple "5k" displays mean ultrawide displays which are still only 2160 pixels vertically.

AFAIK the only 4k iMacs were some

pre-2014 27" iMacs were 2560x1440 which would probably count as "2.5k" in modern money. Its not rubbish (it was the bees knees at the time), but its not 4k.

post-2014 27" iMacs were 5120x2880.

The switch to 5k also meant the end of "target display mode" which let you use iMacs as displays - with good reason initially (there was no widely available external display connection that could support 5k) although that excuse stopped working with Thunderbolt 3.
 

PaulD-UK

macrumors 6502a
Oct 23, 2009
547
255
Quote: "...where you could insert the logic board of a future Mac mini..."
There are numerous (non-trivial) problems to this, in terms of getting external access to all the ports, and getting wifi and BT signals out of the iMac case.
Dozens of people are viewing the output of M* Macs on old repurposed 5K iMac screens, and it MUCH simpler to get a video cable from an externally mounted Mac, than connecting the 9 or so cables needed for an internal conversion. :oops:
 
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PaulD-UK

macrumors 6502a
Oct 23, 2009
547
255
The 2011 uses MXM laptop-style slotted GPU cards (not soldered) that can be removed or replaced.
The problem is finding a MXM card that has a Mac ROM.
A Windows card doesn't work (without soldering a flashed Mac ROM onto it).
Also there are NO compatible cards that support Metal graphics, the is a requirement of Mojave and higher OS versions.

The thing that has changed in the last year or so is that AliExpress has dozens of vendors offering 'Mac compatible' MXM cards - probably refurbished failed ones.

So you could probably keep an old 2011 iMac going for the next 10 years dismantling it every time the GPU fails and fitting another refurbished one.

The other thing that has changed in the last year or so is that even more of them have died, especially the 27" models with the higher spec GPUs. But even base ones are failing.
I'm sure the old thread is still going strong in the forum section ‘Early Intel Macs.’
 
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