macOS Big Sur Does NOT Boot with iMac14,2 System Definition

[tonymacx86]

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OK so macOS Big Sur Public Beta is now out, and we just wanted to clarify things a bit regarding system definitions. For years we here at tonymacx86.com have used iMac14,2 as the suggested system definition in MultiBeast- it was a basic trouble free universal default. Starting with macOS Big Sur, Apple has decided to drop support for iMac14,2 systems.

In order to test your system definition, navigate to the upper left corner and choose About This Mac. A window will open showing the booted system definition. If this shows iMac (Late 2013) you will need to change your system definition before installing macOS Big Sur. In fact, you will not be able to download macOS Big Sur until you change it.

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This is a pain for real 2013 iMacs, as they now have to trick the OS into supporting their platform. However for CustoMacs running Clover, changing your system definition is very simple.

1. Get the latest version of MultiBeast for Catalina
2. Choose Customise > System Definitions > iMac > iMac19,1
3. Choose Build > Install
4. Reboot system

Please note, OpenCore bootloader has a separate method for adding system definition. You may use a text editor such as ProperTree on config.plist or an app such as OpenCore Configurator.

Hope this helps!

 

[trs96]

For those with Haswell and Haswell Refresh systems another option is the Late 2014, Mid 2015 iMac SMBIOS iMac15,1.
It's a closer match for the CPU since it is also Haswell based. I'm pretty sure it will survive the cut with the next version of macOS after Big Sur but there are no guarantees of that. So plan accordingly if you'll need to always be on the latest release of macOS.

All of these three iMacs had AMD Radeon R9 M290 graphics (dedicated) so they are a good match if you are currently using AMD as your primary graphics powering your monitor.

 

[thedocbwarren]

How about Kaby Lake processors and 200 series? Recommendations? I have been unable to make my KL system work successfully in Catalina completely and have used the 14,2 SD.

 

[esafeddie]

The Mac Model that workes very well for me on my hack is iMacPro 1,1 specially for watching DRM content material. The Mac Model iMac19,1 will give you SideCar but Apple TV+ and DRM content will prove difficult on a hack. Safari for some is glitchy but if working, as it is for me, has 4k ability in YouTube and is very, very good.

 

[Stork]

How about Kaby Lake processors and 200 series? Recommendations? I have been unable to make my KL system work successfully in Catalina completely and have used the 14,2 SD.

I'd try iMac17,1.

 

[thedocbwarren]

Cool will do! This machine is pretty standard stuff so should hopefully run Big Sur well.

Are we still thinking Open Core or Clover? Have not dipped into Open Core yet but really considering it.

I'd try iMac17,1.

 

[MduMtshali]

How about Kaby Lake processors and 200 series? Recommendations? I have been unable to make my KL system work successfully in Catalina completely and have used the 14,2 SD.

I’ve been using 18,3 on Catalina. 200 Series, Kabylake user here. Switching to OpenCore significantly improved stability. About to try the Big Sur update. Will keep you posted.

 

[MduMtshali]

Updated through the native Software Update. Took about 45 minutes but no issues. I made sure to update all kexts & Opencore.

 

[thedocbwarren]

I'll gave this a try. My desktop needs an OS upgrade. Was going to update it to a 10th gen i3 (I have a small case) but decided not to.

 

[Cosmix]

Hello all,

In post #1 :

"If this shows iMac (Late 2013) you will need to change your system definition before installing macOS Big Sur. In fact, you will not be able to download macOS Big Sur until you change it"

And here is the way to go :

gibMacOS Tutorial ~ How to Download macOS Directly from Apple

When your Mac is ineligible to download Catalina or Newer macOS versions If your Intel Mac is from approximately 2011/12 or older (see post #2) you won't be able to download Catalina from the Mac App Store. Follow the instructions in these videos to enable the download of Catalina or newer...

www.tonymacx86.com

gibMacOS Tutorial ~ How to Download macOS Catalina on an Older Mac

I was able to download Big Sur Public Beta , create an installation USB ( OpenCore 0.6.0 ) using a real iMac10,1 (Core 2 Duo).

The installation went well on a Fujitsu PC ( CPU i5-4570 / Haswell, 16GB RAM , Realtek Lan 8111, ALC 671 Audio )

The only problem I have on this PC using either Catalina or Big Sur ( both with OpenCore 0.6.0 ) is a "full start instead of a clean wake from sleep".

The same PC ( same BIOS settings ) has no problems with wake from sleep when tested with the latest Mojave and Catalina ( both with latest Clover/kexts ).

Conclusion : I'm waiting for a well crafted Clover/Unibeast/Multibeast pair that does not have "wake from sleep" problems.

Best wishes.