iMac 21.5 versus 27

Greetings all. I am in the market to replace my Mac Mini BTO i7 2011. The motherboard died and replacement cost are high enough for me to consider alternatives. I had upgraded RAM to 16GB and SSD to 500GB. My 23" (matt) aluminum Cinema Display has been my display of choice for 15+ years. I will miss it if I choose the iMac path.

I’ve chosen top of the line Apple desktops over the years more for future proofing than need for top performance. The latter is something I greatly enjoy.

I’d love to hear from folks who have spent time considering whether to invest in a 21.5 inch instead of a 27 inch iMac.

  • What did you end up with?
  • What tipped the scales for you?
  • What were your pros and cons?

I know there is a possibility that the Oct 30 event might introduce an update to the Mac Mini. I certainly will wait and still I am curious to start this conversation.

I look forward to hearing from several of you

27” else you will always wonder if you’d enjoy the bigger screen. I have a family member with a 21” and it’s fine but when I sit down at my 27” it is just so much better. No comparison. Extra screen real estate is lovely. No temptation to add a second monitor.


I went from a 2012 quad-core i7 Mac mini (anyone interested? It still works!) with a Dell 25" monitor, to a 2017 27" Retina iMac. The 21" really wasn’t considered because I was so used to the Dell’s monitor. If you have limited space or budget the 21" model would certainly be a fine choice but I’d recommend looking at the larger machine if possible.

FYI my experience is that you’ll get used to the larger screen very quickly and it will seem natural and not especially capacious.

My wife upgraded from a 2011 21.5” iMac to a 27”. She finds the screen too large sometimes. The 27” screen can be a problem for people that wear bifocals. Computer glasses are a help but then it’s hard to see other stuff like the tv when wearing them.

I use a 27” TB display with my MBP and run into the same issues. However I miss the screen real estate when traveling.

Big advantage to the 27” is the user upgradable memory.

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I got my 27" 3.8 GHz i5 iMac with the 8Gb base memory then upgraded on my own, which took all of two minutes and involved opening a door in the back and slotting in the RAM.

If I’d gotten the 32Gb RAM upgrade from Apple it would have cost $600 more, but you can buy Crucial RAM with a lifetime warranty for $285 right now on Amazon. And by upgrading yourself you get the RAM upgrade plus the original 8Gb sticks, whereas with Apple they just give you 32Gb.

If you get the 21" iMac extra RAM is not user installable. (At least, there’s no door or easy way to do it without considerable disassembly.) So you’ll need to pay($) for the RAM you want in advance.

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Definitely the 27" if you have the room, and especially if you have the room don’t toss your old display but use as a second display. My Dell 20" 2000x1600 pixel display came with the last PC I bought, back in 2004.

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Twenty-seven because it’s bigger. But I always thought laptops and little iMacs made for those that didn’t know any better. :roll_eyes: …living and loving phones and iPads.

I’ll be the dissenting voice.

I switch between a 27" iMac and an 11" MacBook Air every day. Screen size is irrelevant for me. I use computer glasses with each most of the time. My point is, we are amazingly adaptable and get used to whatever we have.

The OP said he would miss the cinema display so the 21.5 choice might be better if he has room to put a second monitor on the desk. But it sounds like he’d really like a new Mac Mini. I hope Apple comes through.

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I pondering long and hard 21" over 27" 2017 iMac. My previous iMac being a 2008 20". Thinking the 27" would be to big on my desk… But truth is its not, 27" just gives you a while lot more space (for me that editing photos) and it doesn’t take to long be become assured you made the right choice. And the RAM is user upgradeable, not sure it is on the 21"…I may be wrong!!

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I like my 2014 21.5" iMac. On my desk it is just fine. I really think my next one will be a 27" or what ever is available at the time. I plan to keep this one around as long as possible. I am using my iMac more now than when I first bought it.

I went with a 27’’ iMac both times. Once you have a screen that big, it’s hard to go back. I use two 27’’ cinema displays at work (just the iMac at home).

  • What did you end up with? 27’’
  • What tipped the scales for you? For the new one, the 5k screen is so pixel crisp, and all the extra real estate is hard to beat. Also, a big one for me was the RAM is still user upgradable so I was able to put 32GB of ram in from the original 8 it came with.
  • What were your pros and cons? The main Pros are above. The only cons are it’s more $$, but not really when you consider the price soft 5k displays and it takes up more space on a desk. But overall not that much more space.
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I guess I’m in the very small minority who much prefers the smaller size of the 21.5" iMac. The 27" iMac feels too big. :slight_smile:

I’m running the 27” with two external 24” 4K displays, so not too big for me.

Must be like getting a suntan everyday with 3 monitors running :sunglasses:

I have both. I kept my 21.5 (late 2013) and it sits next to my radio gear. It is a mostly solid machine. I toyed with selling it. Decided to keep it.

I bought a 27” In March. I have a second 27” monitor for a dual monitor setup. I like the 27” screens. I do not dislike the 21.5”. It is nice having a smaller footprint.

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