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FedoraTime

macrumors member
Original poster
Feb 22, 2024
43
1
Hi, I have a 2013 iMac. It's running on Mojave currently, I want to upgrade it to the OLDEST supported OS, which I believe is Big Sur.

In Software preferences I clicked to upgrade to Catalina (which seemed sensible given past bugs of skipping past Catalina). The process completed, so I am now running on Catalina, I expected to see "Upgrade to Big Sur" in Software prefs, but it's not there. It says my machine is up to date?!

I'd be grateful for any idea how to move from Catalina to Big Sur from here, apparently without any help from Apple's Software Update facility!
Thanks
 
Dammit! What a waste of a great machine (32gb RAM, beautiful screen, 2TB SSD...)
Oh well, I refuse to waste, Linux here we come. Nice knowing you Apple! (Not really)
Thanks
 
OCLP works quite nicely on that 2013 iMac. I have done that (a 2013 21.5-inch), using Ventura currently.
That would get you a long ways down the road, before you would need to go further.
And, that would allow you to continue on with the Apple family you know and love :cool:
(Still considering going to Sonoma. It's a work computer, so I don't like to jump ahead too often... )
 
Sorry, I haven't a clue what you mean! What is OCLP? You're running Ventura on a 2013 machine? Pray tell more! :D
(You're talking to someone who had to look up what Sonoma is. :D )
 
OCLP (OpenCore Legacy Patcher)
It is software that offers a method to run newer Mac OS versions on older, unsupported Macs
It can give you a newer operating system that gets close to what you would have with supported Macs.
It's not always perfect, such as an extra few steps that you have to take each time when updating your patched system.
But, it can work well enough for many users to continue another few years with otherwise-obsolete Macs.
It's the only way that I can run the latest Mac system version on an Early 2008 iMac (that Apple only supported up to El Capitan (OS X 10.11). It's an old Mac that I use as a hobby system, and for a fun project. Even with an SSD, it's kinda slow -- but, it runs the latest system. The 2013 iMac that I have runs MUCH better, but it has more RAM, and an internal upgrade to a PCIe SSD, so fast drive, more than sufficient memory, I should get another 5 years or so from that.
 
In Software preferences I clicked to upgrade to Catalina (which seemed sensible given past bugs of skipping past Catalina).
I hope you have modified it to use a SSD. Catalina has converted the disk to APFS, which is a slow HDD killer.
 
OCLP (OpenCore Legacy Patcher)
It is software that offers a method to run newer Mac OS versions on older, unsupported Macs
It can give you a newer operating system that gets close to what you would have with supported Macs.
It's not always perfect, such as an extra few steps that you have to take each time when updating your patched system.
But, it can work well enough for many users to continue another few years with otherwise-obsolete Macs.
It's the only way that I can run the latest Mac system version on an Early 2008 iMac (that Apple only supported up to El Capitan (OS X 10.11). It's an old Mac that I use as a hobby system, and for a fun project. Even with an SSD, it's kinda slow -- but, it runs the latest system. The 2013 iMac that I have runs MUCH better, but it has more RAM, and an internal upgrade to a PCIe SSD, so fast drive, more than sufficient memory, I should get another 5 years or so from that.
I am frigging blown away by this! Doesnt seem beyond me to do it either (https://yewtu.be/watch?v=eGR2qGw9lG8)

We have several old macs in the family, a 2011 mac mini for TV machine which is buggy as hell due to no updates. I am definitely gonna try this, amazing, thanks!
 
Hi, I have a 2013 iMac. It's running on Mojave currently, I want to upgrade it to the OLDEST supported OS, which I believe is Big Sur.
No you don't; you only think you do. Trust me: you don't.
I clicked to upgrade to Catalina (which seemed sensible given past bugs of skipping past Catalina). The process completed, so I am now running on Catalina...
And now your computer is a sluggish paperweight with Catalina/APFS grinding its rotational drive to pieces -- exactly as Apple intended to artificially obsolesce your machine.
I'd be grateful for any idea how to move from Catalina to Big Sur from here, apparently without any help from Apple's Software Update facility!
Here's the truth: you're not going to get any help from Apple whatsoever, because the company is in full-blown-evil mode now, and has been for some time.

Advice: go *back* to Mojave, but run it from HFS+ (see 2nd paragraph here).
 
Then you are fine. macOS should run on a SSD from Catalina upwards.
Any version of the MacOS whose Disk Utility can recognize and partition an SSD can be installed upon and booted from it, You certainly don't Catalina, which came out nearly a decade after SSDs were available as an option.
 
Any version of the MacOS whose Disk Utility can recognize and partition an SSD can be installed upon and booted from it, You certainly don't Catalina, which came out nearly a decade after SSDs were available as an option.
Of course, OSX runs well from SSDs, emulating HD drives. That was not my point.

I emphasized on "shoud", not "can". Apple lets Catalina and ff. run on APFS formatted HDDs.
That leads to awfully slow performance after a few weeks.
Is that stupidity or a vilain planned obesolescence?
 
I emphasized on "shoud", not "can". Apple lets Catalina and ff. run on APFS formatted HDDs.
That leads to awfully slow performance after a few weeks.
Is that stupidity or a vilain planned obesolescence?
Catalina is going to be painfully slow on anything made in 2011 (even with an SSD) if it's painfully slow fresh-installed on a 16" i7 MBP. Catalina is garbage; it exists for the sole (corporate) purpose of deprecating paid-for software *and* hardware.

If you have a intel Mac that's run Mojave, do so, and clone it to a MacOS Extended (journaled) partition. It's the last fast OS that runs all the great stuff.
 
Couldn't agree more, except I won't be choosing to run what is now an insecure old OS, not when Linux Fedora is around. Time to take the full plunge and dump APple out of my life for good. Was fun while it lasted, but sometimes we have to say no to evil, even if it means a load of work and learning! I dumped Windows for Apple for precisely the same reason many years ago, I guess it's time for that big step again. At least Windows never CLAIMED To give a **** about our privacy, Apple are utterly evil, and consummate hypocrites. Screw them.
Thanks guys
 
Couldn't agree more, except I won't be choosing to run what is now an insecure old OS...
The most "secure" operating systems are the ones that aren't being targeted. I.e., nobody is currently writing viruses for 32bit software. --If you run Mojave in a 2019 Mac, and eschew the i-widget ecosystem in preference for third-party apps, you're arguably more secure that running the latest Safari and iCloud on the latest MacOS. The mere fact that you're not daily archiving your personal crap on the drives of Apple's intelligence-partner patrons is the biggest determinant factor here.
....not when Linux Fedora is around....
Uhm....
Time to take the full plunge and dump APple out of my life for good.
Already done. Mojave is the last MacOS that I have any interest in, and I never use the i-widget applications, and am always logged out of iCloud.

I would enthusiastically jump into any linux fork or emulator of the "old" MacOS that actually ran Mac applications.
 
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