Unsupported macOS Update on "iMac 21.5 Mid-2011"

[tsuedan]

Hi guys,
Does anyone recommend to update an iMac mid 2011 with any MacOS higher than its last supported one "High Sierra" ?
Just in case so, could you guys suggest the best way to do it ?
Thank you in advance

 

[Bigwaff]

Does anyone recommend to update an iMac mid 2011 with any MacOS higher than its last supported one "High Sierra" ?
Just in case so, could you guys suggest the best way to do it ?

What is the exact model and specs of your iMac mid-2011? You definitely should upgrade your RAM and storage from HDD to SSD before upgrade macOS, but depending on your answer, you may have to upgrade the GPU as well.

See -

macOS Catalina Patcher

macOS Mojave Patcher

or

Supported Models | OpenCore Legacy Patcher

Updating to higher version of macOS on unsupported hardware is not for the newbie. You need to know how to get yourself out of trouble.

 

[tsuedan]

Hi @Bigwaff thank you for your feedback.
Good point !
Follow below the specs of my old iMac with some RAM and Storage updates that I recently have done
- Model: iMac 21.5-inch, Mid 2011
- Processor: 2,5 GHz Intel Core i5
- RAM: 32 GB 1333 MHz DDR3
- Graphics: AMD Radeon HD 6750M 512 MB
- Storage: 2TB SSD

 

[padams35]

Either Big Sur or Monterey and using OpenCore Legacy Patcher. Make sure you have a data backup, a bootable USB installer with High Sierra for emergency rollback, and know what newer hardware you will purchase as plan C if things go really sideways.

I think Big Sur was when the OpenCore project finally managed to get working acceleration patches for the HD 6750M and other AMD TeraScale GPUs. I don't know if that fix was backward compatible with Mojave/Catalina.

Monterey is newer, but has a couple spots that are broken without Metal (see known issues: https://github.com/dortania/OpenCore-Legacy-Patcher/issues/108)

Ventura/Sonoma start to accumulate known AVX2 issues and probably aren't worth installing if you are just trying to get Catalina+ to install a mainstream browser update.


Or you can do like I did and just stay on 10.12/10.13 to have a dedicated machine for legacy 32-bit Mac Apps.

 

[tsuedan]

Thank you very much @padams35 !
MAybe I will follow your last suggestion and keep calm with my 10.13 current version