Contribute
Register

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

tonymacx86

Administrator
Staff member
Joined
Nov 18, 2009
Messages
8,659
Motherboard
PRIME Z490-A
CPU
Core i5 10600K
Graphics
Radeon RX Vega 56
Mac
MacBook Air
Classic Mac
Apple, PowerBook
Mobile Phone
iOS
IMac_vector.svg.png
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.

Screen Shot 2016-08-30 at 11.05.34 AM.png

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!
:geek::ugeek::mrgreen:
 
Last edited:

trs96

Moderator
Joined
Jul 31, 2012
Messages
17,380
Motherboard
GA-Z97X-UD3H-BK
CPU
i5-4690K
Graphics
HD4600 / RX 570
Mac
iMac, Mac mini
Mobile Phone
Android
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.

Screen Shot 1.jpg

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.

Screen Shot 3.jpg
 
Last edited:
Joined
Nov 13, 2016
Messages
448
Motherboard
Gigabyte Z270M-D3H
CPU
i3-7350K OC 4.5GHz
Graphics
RX 580
Mac
MacBook, MacBook Pro, Mac Pro
Classic Mac
Classic
Mobile Phone
iOS
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.
 
Joined
Mar 9, 2012
Messages
2,149
Motherboard
Gigabyte Z390 AORUS Pro WFI
CPU
i5 << need model # >> See Rules !!
Graphics
RX 580
Mac
iMac, Mac Pro
Mobile Phone
iOS
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

Admin
Staff member
Joined
Sep 21, 2010
Messages
13,449
Motherboard
ASUS ROG MAXIMUS X HERO Z370
CPU
i7-8700K
Graphics
RX 580
Mac
MacBook Pro, Mac mini, Mac Pro
Classic Mac
Power Mac, PowerBook
Mobile Phone
iOS
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.
 
Joined
Nov 13, 2016
Messages
448
Motherboard
Gigabyte Z270M-D3H
CPU
i3-7350K OC 4.5GHz
Graphics
RX 580
Mac
MacBook, MacBook Pro, Mac Pro
Classic Mac
Classic
Mobile Phone
iOS
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.
 
Joined
Apr 4, 2017
Messages
33
Motherboard
Z270X Gaming 7
CPU
i7-7700K
Graphics
RX 480
Mobile Phone
iOS
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.
 
Joined
Nov 13, 2016
Messages
448
Motherboard
Gigabyte Z270M-D3H
CPU
i3-7350K OC 4.5GHz
Graphics
RX 580
Mac
MacBook, MacBook Pro, Mac Pro
Classic Mac
Classic
Mobile Phone
iOS
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.
 
Joined
Aug 26, 2012
Messages
7
Motherboard
GA-H67M-D2
CPU
i3-2120
Graphics
RX 560
Mobile Phone
Android
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 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.
 
Top