Late 2012 iMac, safe/worth to upgrade to Mojave?

dangerly

macrumors regular
Original poster
Oct 27, 2009
151
5
European Dis-Union
Hello,
i actually own a late 2012 27" iMac (3.4 GHz i7, 24 Gb ram) running Sierra.
I know this iMac supports Mojave, what i would like to know is if it is safe and worthwile to upgrade to Mojave?
Thank you
 

zen

macrumors 68000
Jun 26, 2003
1,713
471
Mojave is noticeably slower on my late 2013 Macbook Pro than High Sierra is (was). Given the similar age of our machines, I would suggest you will notice something of a slowdown too.
 
  • Like
Reactions: ATC

jtara

macrumors 68000
Mar 23, 2009
1,957
509
It's safe. It's worthwhile. It's a persistent myth that older Macs slow down with newer OSs.

I updated my 2012 Mac Mini to Mojave shortly after it's release, with no trouble. Note (see below) I had already replaced the Fusion Drive. (see below)

You certainly should update. The NEXT time you probably will not get a choice, as your hardware will "age out" and will be unsupported on MacOS "N...."

You will get warnings about 32-bit apps and control panels. You can ignore them. They WON'T work On MacOS "N...."

If anything, it should be faster. MacOS is not a Microsoft OS! ;) Every new update gets these stories about "slow", when usually it is nothing more than Spotlight rebuilding, etc. which is transitory.

My biggest concern about your Fusion Drive is that the hard drive is almost certainly having a near-death experience at this point. Replace it with a flash drive. It will make a HUGE improvement in speed. Not sure if your iMac requires cutting a rubber seal or if the front glass can be removed with magnets.
 

BigBoy2018

Suspended
Oct 23, 2018
964
1,822
The fact of the matter is that every single time theres a new OS, it's going to be problematic for a subset of users.
Computers are complicated and everyone's setup is a little different. And for reasons that only the gods of chaos know, some macs either freeze up, crash, get slower, have kernal panics ... you name it ... after upgrading to a new OS. Unfortunately you're one of the unlucky ones.

All that said, there's also a ton of people who upgrade and inevitably report that their macs are running better, faster, etc.

Bottom line, whenever you upgrade to a new OS

1) Make a backup right prior, so you can restore if something goes wrong
2) If things are a little slow or wonky, and you have the time ... do a clean install and see if that helps.
 
Last edited by a moderator:

dangerly

macrumors regular
Original poster
Oct 27, 2009
151
5
European Dis-Union
It's safe. It's worthwhile. It's a persistent myth that older Macs slow down with newer OSs.

I updated my 2012 Mac Mini to Mojave shortly after it's release, with no trouble. Note (see below) I had already replaced the Fusion Drive. (see below)

You certainly should update. The NEXT time you probably will not get a choice, as your hardware will "age out" and will be unsupported on MacOS "N...."

You will get warnings about 32-bit apps and control panels. You can ignore them. They WON'T work On MacOS "N...."

If anything, it should be faster. MacOS is not a Microsoft OS! ;) Every new update gets these stories about "slow", when usually it is nothing more than Spotlight rebuilding, etc. which is transitory.

My biggest concern about your Fusion Drive is that the hard drive is almost certainly having a near-death experience at this point. Replace it with a flash drive. It will make a HUGE improvement in speed. Not sure if your iMac requires cutting a rubber seal or if the front glass can be removed with magnets.
Opening my iMac requires cutting of the rubber seal. Don't know if i want to go through this. In tha past i replaced the HDDs of 20" and 24" i Macs , Mini and MBP with SSDs. Was thinking about doing so, will see if i get the courage to do it.
iFixit teaches.......................
 

BigBoy2018

Suspended
Oct 23, 2018
964
1,822
Opening my iMac requires cutting of the rubber seal. Don't know if i want to go through this. In tha past i replaced the HDDs of 20" and 24" i Macs , Mini and MBP with SSDs. Was thinking about doing so, will see if i get the courage to do it.
iFixit teaches.......................
If you're talking about replacing the spinning part of the fusion drive with an SSD, I've done it on several iMacs. Never had a problem. My current 2017 27 inch iMac has a 4TB Samsung 860 evo in place of the spinning drive.

I actually think the tape seal is easier to deal with than the screws from the 2012 and earlier iMacs. Just use the little 'pizza cutter' tool that iFixit sells. Plus there's only two wires connecting the screen to the board in the current iMacs, compared to the 2012 and earlier - which had four.

Finally, the 2017 iMacs (both 21.5 and 27) do NOT require any kind of thermal sensor to be installed if you drop in a new SSD in the spinning drive bay.

Just take you're time, take care, and you'll be fine!
 
  • Like
Reactions: filmak

jtara

macrumors 68000
Mar 23, 2009
1,957
509
If you're talking about replacing the spinning part of the fusion drive with an SSD
On my Mini, I replaced the SSD and left the spinning drive to use for utility. But I wish I had removed it, as it has grown defects and close to death, and cooling would be better without it.

I didn't feel the small/slow SSD that came with the Fusion was of any worthwhile use.

Of course, this is easier on a Mini than on an iMac!

You will get a HUGE performance gain from an SSD.

How much memory do you have? Is the memory user-upgradable? Another big gain on the Mini was going to 16GB RAM.

Either of these upgrades (if you have less than 16GB) will more than make up for any small performance loss from the OS.

FWIW, I am a software developer - for more than 40 years - and one of my specialities is identifying and removing bottlenecks. I do iOS and Android development, and both have a "build cycle" that can be lengthy. So, I do benchmark build times. There was no degradation with any OS update on my Mini.

I do currently use an iMac Pro, as the build time is 4x as fast as the Mini. But the Mini is still in service, and perfectly fine for email, browsing, etc.
 
  • Like
Reactions: BigBoy2018

BigBoy2018

Suspended
Oct 23, 2018
964
1,822
I do currently use an iMac Pro, as the build time is 4x as fast as the Mini. But the Mini is still in service, and perfectly fine for email, browsing, etc.
I've been around for a while as well (34 years a mac user). I still chuckle when someone says something like that about the 2019 mac mini ... that it's 'fine for email, browsing'. I guess my question is when does it finally get to the point when the low end mac is more capable than just 'fine for email and web browsling."

After all, that's what people said about the first G4 mac mini 14 years ago, that it's 'perfectly fine for email and browsing'.

This current Mini is, IDK, maybe 30 times faster than that 2005 mac mini? But people say it's still only really suited for light use!! (i.e. email and browsing). Now you are right that web sites have gotten that much more demanding and so has email, and take a lot more processing power than they did a decade and a half ago ...

But I imagine three decades from now when the budget computer is 100 times as fast as today's budget computers and people are still saying it's best suited for just email and browsing :p
 
Last edited:

jtara

macrumors 68000
Mar 23, 2009
1,957
509
I still chuckle when someone says something like that about the 2019 mac mini
Mine is a 2012. And I used it for development until very recently. My 2009 Aluminum Macbook is just fine for email, browsing, etc. as well. the 2012 Mini would still be fine for web development, and OK for app development. But, with a build cycle - a 4X improvement in build cycle is a huge productivity gain.

FWIW, I think the upcoming Mac Pro will come in WAY more massive forms than anybody has been projecting. I think up to $50,000 to $100,000, to target Hollywood production. It's a place where time is money.

But there are comments on Reddit complaining about browsing speed when they updated to Mojave.

As far as websites - lousy websites are lousy. And when they are lousy they are seldom fixed with a faster processor or more efficient OS. It's just that they load a gazillion unneeded scripts. I'm looking at you, AT&T! Some of the biggest enterprises are the worst offenders. You'd think the likes of AT&T could afford to hire the best developers. Instead, they ship it off to underpaid third-world developers to paste on yet another layer of Javascript on top of the garbage they already have. Horrors like multiple scripts that do the same thing, but each one is from a different iteration of the page. They add, but never subtract. Multiple Javascript frameworks. Eeek!

So, OS is updated. ATT - or your bank - adds another layer of garbage as they do EVERY year - and then you blame it on the OS.

Even those garbage sites work OK for ME, on my oldest hardware. But that's because I have a gigabit symmetrical connection to Google Fiber (Webpass, actually) and about 5mSec latency to L.A. and major backbone connections. So all those garbage scripts load FAST. Neither the browser, the computer, nor the OS are the roadblock.
 
Last edited:
  • Like
Reactions: BigBoy2018

Racineur

macrumors 6502
Jun 11, 2013
300
61
Montréal, Québec
Opening my iMac requires cutting of the rubber seal. Don't know if i want to go through this. In tha past i replaced the HDDs of 20" and 24" i Macs , Mini and MBP with SSDs. Was thinking about doing so, will see if i get the courage to do it.
iFixit teaches.......................
Hello. I have a late 2012 iMac 27 - 24 RAM - 1TB FD - 3,2 GHz Intel Core i5 - NVIDIA GeForce GTX 675MX 1024 Mo. I have these OS installed on external SSD : El Capitan, Sierra, High Sierra, Mojave. Mountain Lion is still installed on the internal 1TB Fusion Drive. Fastest OS for my old iMac is in this order: Mountain Lion, El Capitan, Sierra, High Sierra, Mojave. So, the slowest is Mojave. But it works, don't worry. Hard to see the difference between High Sierra and Mojave but easy to between Mojave and Sierra and El Capitan. Most difficult tasks for my iMac are of graphical nature like drag & drop pieces of texts or pictures on the desktop. Photos is definitely slower but old apps like Aperture and Lightroom are blazing fast surprisingly. Some apps don't open like some add-ons for Lightroom like Viveza and the likes. As for the dark mode, I can live without. It's very obtrusive being all over the place. Still prefer the dark Menubar and Dock of the other OS. Being wise, I'd stick to El Capitan or Sierra but Im not and I'm on Mojave more of the time. But I also find myself switching back to Sierra or High Sierra some times. Too bad, Mountain Lion is half usable now. It was blazing fast for this 2012 iMac. Now you've got the whole picture my friend. R.
 

dangerly

macrumors regular
Original poster
Oct 27, 2009
151
5
European Dis-Union
Hello. I have a late 2012 iMac 27 - 24 RAM - 1TB FD - 3,2 GHz Intel Core i5 - NVIDIA GeForce GTX 675MX 1024 Mo. I have these OS installed on external SSD : El Capitan, Sierra, High Sierra, Mojave. Mountain Lion is still installed on the internal 1TB Fusion Drive. Fastest OS for my old iMac is in this order: Mountain Lion, El Capitan, Sierra, High Sierra, Mojave. So, the slowest is Mojave. But it works, don't worry. Hard to see the difference between High Sierra and Mojave but easy to between Mojave and Sierra and El Capitan. Most difficult tasks for my iMac are of graphical nature like drag & drop pieces of texts or pictures on the desktop. Photos is definitely slower but old apps like Aperture and Lightroom are blazing fast surprisingly. Some apps don't open like some add-ons for Lightroom like Viveza and the likes. As for the dark mode, I can live without. It's very obtrusive being all over the place. Still prefer the dark Menubar and Dock of the other OS. Being wise, I'd stick to El Capitan or Sierra but Im not and I'm on Mojave more of the time. But I also find myself switching back to Sierra or High Sierra some times. Too bad, Mountain Lion is half usable now. It was blazing fast for this 2012 iMac. Now you've got the whole picture my friend. R.
For the moment i will stick with Sierra.
In the near future will replace the fusion drive with a SSD.
Thanks to everybody for the replies and suggestions.
 

saudor

macrumors 6502a
Jul 18, 2011
775
539
it's fine. My 2010 is not even supported and it runs a bit smoother than high sierra
 
Register on MacRumors! This sidebar will go away, and you'll see fewer ads.