I recently found my MacBook Air 2017 becomes slower after upgrading it to the latest macOS. And, now it's too slow when I write code in vsCode and if I switch screens then it's laggy sometimes. I have already tried to upgrade vsCode & macOS also removed extensions but nothing changes. I have seen some laptops with the same configuration and ubuntu installed on them work fine with the same project. So, I think the newer version of macOS is good for newer models.

So, should I downgrade my macOS to the previous version which was installed in it when I bought it?

MacBook Air 2017: 1.8 GHz Dual-Core Intel Core i5 with 8 GB 1600 MHz DDR3

Memory usage: Activity Monitor Memory Usage of MacBook Air 2017

CPU usage: Activity Monitor CPU Usage of MacBook Air 2017

  • Did you have a look at Activity Monitor to check which processes use a lot of CPU?
    – nohillside
    Commented Sep 14, 2022 at 16:56
  • 3
    We’re pushing all our macs at work to the newest os. Many are older and slower than your Mac. What we do have to do is erase the storage. That lets the new OS land on a clean drive for best speeds.
    – bmike
    Commented Sep 14, 2022 at 17:28
  • @nohillside I have attached a screenshot of the memory usage activity monitor Commented Sep 15, 2022 at 7:18
  • Nice update. The energy use after 4 or more usage hours is an excellent item to review but the 80% idle CPU shows you don’t have stuck processes or a scheduling problem for new processor tasks.
    – bmike
    Commented Sep 15, 2022 at 7:55

2 Answers 2


In general, no. An erase and install on the latest OS generally gets the best performance on macOS.

Most of the speed gains come from the erase and install, so you can do the erase and install and get the latest OS for best support, security and often performance.

The erase step is key, doing that from recovery and then installing the latest seems to restore a ton of speed for our 2013/2015 and newer Macs at work.

  • 1
    Does erasing everything and then putting it all back bring 'speed gains'? Or do the gains come from NOT putting back stuff like out-dated third-party extensions, drivers, background processes, etc.?
    – benwiggy
    Commented Sep 14, 2022 at 17:51
  • Both items add different speedups in my experience. Even restoring everything from the backup is better than upgrading, @benwiggy
    – bmike
    Commented Sep 14, 2022 at 18:49
  • So by what process does erasing speed things up? Defragging???
    – benwiggy
    Commented Sep 15, 2022 at 6:41
  • @bmike I think if nothing works out I have to clean my mac and reinstall macOS. Commented Sep 15, 2022 at 7:25

In general, if Apple says a new OS can run on your Mac, then it should run as well as older versions. One of the reasons they cut off older Macs is because they can't get or guarantee decent performance.

Definitely have a look at Activity Monitor: see what processes are using the most CPU and memory. What's your RAM usage? (Bear in mind that with only 8Gb, macOS will use it all -- but how is it being used? What's the memory pressure, and how much swap?)

Also, make sure that any third-party Launch Agents, Login Items, and other 'background' processes are up-to-date and compatible with the new OS. You could also try clearing caches (boot to Safe Boot mode, and out again.)

Also, you say you've upgraded VSCode. Any chance that the new version (and other software you're running) is just more demanding? Let's face it, a 2-core 8Gb Air is not the development tool of choice, even in 2017.

  • I have attached screenshots of memory & CPU usage. Also, I have tried clearing caches and updating all 3rd party apps and vsCode to the latest one. But not tired of safe boot mode. Commented Sep 15, 2022 at 7:22
  • 1
    @HarshMishra Stop using Chrome, which is a massive resource hog. Also get rid of "CleanMyMac", which is unnecessary at best.
    – benwiggy
    Commented Sep 15, 2022 at 8:15
  • I can use safari instead of chrome but "CleanMyMac" is useful for cleaning caches. That's why I haven't removed it. If there is any alternative to clear caches please suggest it. Commented Sep 15, 2022 at 8:19
  • @HarshMishra Caches do not normally need to be 'cleaned', unless there is a problem with the cache data. Empty caches will slow you down for sure! Rebooting into Safe Boot mode will clear caches.
    – benwiggy
    Commented Sep 15, 2022 at 8:54
  • My MacBook is too slow and laggy in the safe boot. I tried to open the vsCode but it's not working. Commented Sep 15, 2022 at 16:03

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