I have been successfully running Cubase Pro 11.0.30 (although a later update messed up - rumoured - because of an issue with VST cloud, so I had to downgrade to make it work successfully again. It seems very disloyal of Steinberg to make new versions NOT compatible for the main functionality.
I have a iMac 27 (2011) with a ton on RAM, fast Thunderbolt 2 hard discs - and the program superbly and smoothly on it. If Cubase 12 doesn’t run, I think it is time for me to say goodbye to Steinberg and my custom - as I am retired and I can’t afford a new computer and that is saying something… as I bought in for Atari in 1989 and have upgraded every year since.
I’ve done it to my late 2011 MacBook Pro and my studio MacPro 2013. Both work extremely well and I’m able to run the latest versions of Cubase & Dorico, and Pro Tools 2022 - it was to upgrade Dorico that I took the plunge.
I’d strongly recommend a full clone back-up of your iMac first of course, then if it doesn’t work well you can revert.
I also have a mid 2011 27in iMac like Robert and unfortunately because of the graphics card they used in this model it’s impossible to do that procedure. I’d caution Robert to look into it before attempting.
I backed up and then decided I was going to try the dosdude upgrade - I read and acknowledged the warnings on the website. I wanted to try it out before testing out other options and the machine is not mission critical if I had to do a reinstall.
Amazingly, when it initially completed it had a bit of lag but the lag but was relatively smooth - so I installed my upgrade for NI Komplete (delayed for the same reason as Cubase) and I bit the bullet and bought and installed Cubase Pro 12. Since the upgrades it seems to have has got slower and laggy. So I am now considering the options - I will play with it for short while before I do anything and see if there is anything to do.
I am also discussing swapping the iMac with a friend for a newer Mac mini with less RAM (as he would appreciate the iMac screen, I think) and try that out.
That said, thank you both for your help. The journey continues to keep me interested at least.
I have a macbook pro early 2011 runing Dosdude patch for Catalina, and works great (Cubase 12 included). My upgrade was installed on top of dosdude patch for Mojave (that also was working better than High Sierra).
But I have 1 Tb SSD and 16 gb RAM.
Another possible way is using opencore legacy for Catalina.
I don’t think this version of cubase will go past the installation process of an unsupported OS, this time.
Tried to install C12.0 on Mojave, unsuccessfully: the install didn’t even start as I got a warning message “unsupported OS”.
I have succeeded sofar in installing BIG SUR on my Macbook PRO early 2011. And now I installed Cubase 12 and it ssems to work fine. Only the Genie stuff on the macbook does not perform wel due to an issue with the GPU for a 17" macbook pro version. I used the latest installation version of dortania OpenCore-Legacy-Patcher