How to speed up macOS Big Sur


I was pretty excited to upgrade to macOS Big Sur. As a major version change it introduced all sorts of shiny new things! Unfortunately, for the first time in my macOS journey, the update went more like a Windows update of years gone by and I found myself wishing I could go back to the previous OS version. Don’t get me wrong, everything worked, and it looked great. It’s just that my speedy 2019 MacBook Pro was laggy, missed keystrokes, and apps loaded much more slowly than they did before the update. This seemed to get worse with time, but I’m not sure about that. I may have just become more aware of the overall sluggishness as time went on.

My guess is that everyone on the macOS team at Apple has been on Apple Silicon machines for at least a couple of years and they may not have taken the time to update (and use for an extended period) an Intel machine before releasing Big Sur so they are blissfully unaware that they now have millions of frustrated users. Regardless, my Mac was slow and I wanted it back to the speed it was before.

After reading on a few sites around the good ol’ internet that Big Sur sluggishness is not uncommon, I decided to try erasing the hard drive, do a fresh install of Big Sur, then restore a backup. Just like I had to do after every single Windows update back in the day. The saving grace is that now there are some tools that make this relatively painless and you can be back in business within a couple of hours instead of a couple of days.

I’m thrilled to say that my machine is much faster than it was! It feels just like it did running macOS Catalina.

Steps Involved

  1. Find an external hard drive at least as large as the space you’re using on your Mac’s boot drive
  2. Erase and format the external drive as APFS using Disk Utility
  3. Download and install Carbon Copy Cloner
  4. Make a complete backup onto the external of your Mac’s boot drive using Carbon Copy Cloner
  5. Boot your Mac into Recovery Mode
  6. Erase your Mac’s boot drive
  7. Reinstall macOS Big Sur and boot into it
  8. Restore your backup using Migration Assistant
  9. Enjoy a faster Mac

Before continuing, please understand that this is just a guide to try to help you get your Mac back and we are not responsible for any data loss that may occur. Do this at your own risk. If you are not comfortable formatting drives, etc. please seek professional assistance with your slow Mac.

That being said, the process is not terribly complicated and it certainly seems to have helped my machine.

How to Erase & Format an External Drive Using Disk Utility

Figure out how big your Mac’s internal hard drive is by clicking on the Apple menu  in the upper left of your screen. Then click on “About This Mac” on that menu. On the popup window that appears, click on “Storage” where you’ll see something like this:

You’ll need an external drive at least as large as the space you’re using on your internal drive. I used a 500GB Sandisk USB-C SSD which made this whole process really fast.

Plug your external drive in to a USB port on your Mac and open Disk Utility. You can find Disk Utility in the “Other” folder in Launchpad. Or you can click on the magnifying glass in the upper right of your screen (Spotlight) and type in “Disk Utility” then hit Return to open it.

You’ll see a screen like this:

Select your external drive in the column on the left. In my case it’s called Mac Backup. Then click on Erase in the upper right of the Disk Utility window. You’ll see a popup like this:

Enter a name that you’d like to use and choose APFS or macOS (Journaled) (either one is fine) as the format and then click on Erase. Disk Utility will do its thing and format and erase the external drive. After it finishes, click Done and close Disk Utility.

Carbon Copy Cloner

Carbon Copy Cloner (CCC) is an awesome tool to have for your Mac. It’s reasonably priced and I recommend purchasing it. They have a 30 day fully-functional trial which will allow you to do what you need to for this exercise.

Download CCC here and follow the installation instructions on the download screen in your browser.

Open CCC by clicking on Launchpad in your Dock and clicking the CCC icon or click on the magnifying glass (Spotlight) icon in the upper right of your screen and typing “Carbon Copy Cloner” and hitting Return. Click on “Agree” and then click on “Trial” if you haven’t purchased it.

A help screen will open on top of the app screen. Go ahead and close that. You’ll see this:

Click on the “Tips” button to turn off the yellow tips. In the leftmost column click on the area “Click to Select a Source…”

Select your Mac’s internal drive from the list. For me that’s called “Macintosh HD”. Now click on the center column area “Click to Select a Destination…” and choose your external drive in my case “Mac Backup”

Click on “Data Only” at the bottom of the popup:

Click on “Clone” at the bottom of the CCC window and then “Install CCC’s Privileged Helper Tool” when prompted and follow instructions. CCC will make an exact copy of your Macintosh hard drive.

Boot Into Recovery Mode, Erase Drive, Reinstall macOS

Your computer must be connected to the internet. If you’re reinstalling on a Mac notebook computer, plug in the power adapter.

  1. Start up your computer in macOS Recovery:
    • On a Mac with Apple silicon: Choose Apple menu > Shut Down, press and hold the power button until you see “Loading startup options,” select Options, click Continue, then follow the onscreen instructions.
    • On an Intel-based Mac: Choose Apple menu > Restart, then immediately press and hold Command-R until you see a spinning globe appear.
  2. In the Recovery app window, select Disk Utility, then click Continue.
  3. In Disk Utility, choose View > Show All Devices.
  4. Select your startup disk on the left, then click Erase.
  5. Click the Format pop-up menu (APFS should be selected), enter a name, then click Erase.
  6. After the disk is erased, choose Disk Utility > Quit Disk Utility.
  7. In the Recovery app window, select “Reinstall macOS,” click Continue, then follow the onscreen instructions.

I chose to exit Recovery Mode at this point and boot into macOS Big Sur. It may be possible to stay in Recovery Mode and choose “Restore a Time Machine Backup” from there which would streamline the process a bit. By booting into Big Sur I had to create a user account which was removed and replaced when I restored my backup using Migration Assistant.

Restore Your Backup Using Migration Assistant

Open Migration Assistant by clicking on the icon under “Other” in Launchpad or clicking on the magnifying glass (Spotlight) and typing “Migration Assistant” and hitting Return.

Click “Continue” and choose “From a Mac, Time Machine backup, or Startup disk”

Click “Continue” and follow the instructions. When asked if you want to replace the user account with the user account from the backup, choose yes. This will put your Mac back exactly the way it was before.

I had to uninstall then reinstall my Wacom driver and Logi Options. Other than that, everything appears to work as before with the snappiness that was missing before this exercise.

In Summary

This process made my 2019 MacBook Pro much faster than it was after updating to Big Sur from Catalina. Why? I have no idea. There must be highly fragmented files or remnant system processes lingering around after the update. I hope that Apple figures this out moving forward.

Unfortunately I’m not convinced that Apple won’t care about Intel-based Mac users having sluggishness issues. The move to M1 silicon may be just like every other “move forward” decision Apple has made throughout its history. Remember the move to USB-C only? I was outraged that all my USB devices would need to be replaced or use a dongle. Today I love USB-C and see the logic behind that decision. I don’t like the idea of investing in a new MacBook in a year or two, but from what I’ve read about the M1 silicon my attitude may change.

Let me know in the comments how this process worked for you!

Posted in macOS.

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