Apple’s latest macOS is named after the coastal region of “Big Sur” along the Central Coast of California. “Big Sur” is designed to to support Macs with ARM-based processors known as Apple silicon. As of today, the latest production release is version 11.2.

Once again, Apple discontinued support for older Mac devices to run this “Big Sur” operating system.

“Big Sur” Mac Hardware Minimum Requirements
MacBook (2015 or later)
MacBook Air (2013 or later)
MacBook Pro (Late 2013 or later)
Mac mini (2014 or later)
iMac (2014 or later)
iMac Pro (2017 or later)
Mac Pro (2013 or later)

My 27 inch iMac late 2013 missed out on this macOS update. I suspect, although it’s 100% capable of running this “Big Sur,” if it has the notorious Fusion Drive as a system drive it struggles running the new macOS with smooth operation.

You should avoid Mac computers or Windows PCs that have “Fusion Drive” inside as you are only asking for trouble.

Big thanks to genius BenSova releasing Patched Sur for Mac users having unsupprted Mac computers running this “Big Sur”

You can get Patched Sur program from this link.

To create an installable patched “Big Sur” USB thumb drive, you need to have a macOS Catalina (10.15.*) environment. (I created the Catalina environment with an external USB connected SSD drive with the bare minimum configuration for this exercise.)

Please always test with an external usb connected SSD drive (conventional hard drive is too slow to operate) to run patched “Big Sur”.

You will be inundated with a number of postings, but as a start, you can take a look at (MacRumors) macOS 11 Big Sur on Unsupported Macs Thread.

If you require video assistance, Mr. Macintosh YouTube channel is the place to go.

As a result, I now have “Big Sur” 11.2 on my iMac 27 inch late 2013 and so far absolutely no issues (performance wise, much better than running Catalina – I hate to say but Catalina was a disastrous operating system and I did not like it at all).

Take a look at the following image for proof.

Big Sur running on unsupprted iMac


24/2/21 MacOS Big Sur is now updated to ver 11.21.  I applied this update downloading full installation *.pkg file created updated USB stick base installation media.  As far as I tested with my iMac 27 inch late 2013, BenSova’s Patched Sur ver 0.4 beta was the only version worked.  (Most recent version is now 0.7 beta).  Much of process involved for this update for installing USB connected SSD drive – not straight forward process at all.  Finally, my iMac 27 inch 2013 is now running Big Sur ver 11.21

Big Sur running on unsupported iMac ver 11.21

Big Sur ver 11.21

If you need help for Mac computers  (Sydney CBD, Sydney North Shore – particularly in Chatswood, Roseville, Lindfield, Killara, Gordon, Pymble, Turramurra, Wahroonga, Warrawee, Hornsby, Macquarie Park and St Ives area) please contact Harry 0417 424 909.  Or refer to our Service page.

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