iMac OS downgrade question

[macguru9999]

A friend of mine runs Vectorworks for her landscape business. It needs catalina or below (not big sur) She needs a new iMac. Question: If she gets a 2020 iMac and it comes with Big Sur, how hard is it to install Catalina ? We know these intel 2020 imacs support catalina , but will the T2 chip block me from installing catalina, or is it just a matter of turning on external boot, erasing the internal ssd , and installing catalina 10.15.7 ??

 

[hg.wells]

Personally I would avoid downgrading a new machine if at all possible.

Have you checked Vectorworks site recently, is your friend using an older version?

Apple macOS 11.0Big Sur Compatibility

Update 12/03/2020 Vectorworks dongle Series B & G and Vision are Intel Big Sur compatible now. Update 11/11/2020 With the official release of macOS Big Sur tomorrow, Nov 12th, I wanted to share some updates with you all from our R&D team: Big Sur Intel – No issues to report at this point ...

forum.vectorworks.net

 

[macguru9999]

Vectorworks 2021 supports Big Sur, we now know ... so its moot

 

[ambientdaw]

Personally I would avoid downgrading a new machine if at all possible.

Have you checked Vectorworks site recently, is your friend using an older version?

Apple macOS 11.0Big Sur Compatibility

Update 12/03/2020 Vectorworks dongle Series B & G and Vision are Intel Big Sur compatible now. Update 11/11/2020 With the official release of macOS Big Sur tomorrow, Nov 12th, I wanted to share some updates with you all from our R&D team: Big Sur Intel – No issues to report at this point ...

forum.vectorworks.net

This is my question today as well! h.g.Wells can you give a reason or two why you recommend avoiding this downgrade on a new iMac?

 

[hg.wells]

The iMac could have newer versions of firmware or hardware drivers that are not included in an older OS.

What is your reasoning for wanting to downgrade?

 

[ambientdaw]

I use the mac for pro audio and some of the apps and plugins are not compatible with Big Sur. Happens every year.

 

[fastlanephil]

Apple still shows the 2020 27” 5K iMac being compatible with Catalina.

macOS Catalina is compatible with these computers - Apple Support

You can install macOS Catalina on any of these Mac models.

support.apple.com

 

[ambientdaw]

Apple still shows the 2020 27” 5K iMac being compatible with Catalina.

macOS Catalina is compatible with these computers - Apple Support

You can install macOS Catalina on any of these Mac models.

support.apple.com

thanks! But about halfway down in these instructions, we are to alter the terminal in order to transfer the Catalina installer to the new iMac. That does not sound so compatible to me! Thoughts?

How to downgrade from macOS Big Sur to Catalina step-by-step

If you’ve installed macOS Big Sur and things didn’t go as planned, you can safely downgrade to Catalina. Here’s how.

macpaw.com

 

[chrfr]

thanks! But about halfway down in these instructions, we are to alter the terminal in order to transfer the Catalina installer to the new iMac. That does not sound so compatible to me! Thoughts?

How to downgrade from macOS Big Sur to Catalina step-by-step

If you’ve installed macOS Big Sur and things didn’t go as planned, you can safely downgrade to Catalina. Here’s how.

macpaw.com

Those directions are just telling you how to make a USB installer for Catalina.