Why You should not upgrade your MacBook Pro to Big Sur

Deni Putra Perdana
4 min readNov 18, 2020

Yes, you didn’t read the title wrong, in this post I will share my experiences after upgrading my machine (MacBook Pro 2018 15") and why you should not do it, or doing the downgrade like me.

If you want to upgrade your pre-silicon MacBooks, check these conditions, and you’re good to go:

  1. Your machine have no discrete GPU or not using external display.
  2. You use your machine in a very very cold room.
  3. Consider this article

Why discrete GPU on MacBook sucks?

It’s began since macOS Catalina, there are too many applications that using GPU Acceleration, and in Big Sur they’re using more and more GPU Acceleration for visual effects here and there. And did you wonder why watching Youtube videos or attending a Google Meet on Google Chrome/Microsoft Edge sometimes lags your machine so bad? Yes, that’s GPU Acceleration too, they’re using VP9 codecs.

source: https://ozmoroz.com/2020/07/macos-kernel-tasks/

Every time my machine lags, I checked Activity Monitor, and it’s always kernel_task eating hundreds percent of CPU but on Big Sur? it’s freezing, it’s not lag anymore, its freeze LOL.

and that’s just the machine’s self prevention for overheating. I don’t know what’s the problem with these GPU, maybe it’s just macOS using older drivers, or maybe hardware problems?

Let’s see the cooling system of the machine


Yes, the GPU and CPU heat are being sent outside of the machine with those small heatsink, no wonder it throttles huh? Maybe you could improve the cooling system, but that will void your warranty of course.

So, how do we handle these issues?

  1. Waiting for Apple to fix this.
  2. Improve the cooling system
  3. Buy another machine, be it a MacBook without discrete GPU or others.
  4. Pray to resolve it.
  5. Downgrade.

For me, the quick fix is downgrade, here’s my graph of my CPU usage before and after downgrade:

graph with https://bjango.com/mac/istatmenus/

Looking at the graph, at first CPU usage on Big Sur is low, like High Sierra. But, once you using them for usual task (coding, meeting or watching videos) it will start throttling and freezing. I did not capture the graph anymore because i deleted that while downgrading my machine.

Lets start the downgrade thing

Here’s the many types of macOS downgrade:

  1. Downgrade using time machine.
  2. Downgrade using external drive.
  3. Downgrade using Internet Recovery mode.

here’s if you want the visuals of the downgrades, you can pick one (sorry i’m not taking any pictures lol):


So, for my case, I don’t have time machine backups, and I ended up creating bootable, but not using it in the end because of I did not set the Allow booting from external media, lastly i’m using Internet Recovery Mode.

Notes for downgrade with Internet Recovery Mode:

  1. Make sure you have internet connection.
  2. Do back up your files!
  3. If you want to reinstall last used macOS, do reinstall macOS in the recovery mode:
source: https://www.imore.com/how-downgrade-macos

3. If you want to reinstall the first macOS that your machine get from the shop do erase your macOS first

Step to erase macOS and Install your machine’s first macOS

  1. Shut down your machine.
  2. Hold down Command+R, and keep holding the keys until your computer reboots. This will put your computer into Recovery Mode.
  3. Click on Disk Utility in the OS X Utilities selector.
  4. Choose your drive and click on Erase.
  5. Change the format to MacOS Extended (Journaled).
  6. Change the name of your drive to something else.
  7. Quit Disk Utility.
  8. Restart.
  9. Hold down Command+R again until Recovery Mode.
  10. Provide your wifi credentials.
  11. After loading is done, you can go Install macOS with first macOS on your machine.
  12. Do the install thingy, next next and you’re done.

And that’s it, your device is as good as new.