I installed an upgrade to OS 14.4.1 and it appears to have caused severe performance degradation. I would like to restore the system from a backup, but I don't know the exact time of the update. I would prefer not to restore multiple versions in order to find the nearest backup with the old OS. Is there a way to figure out exactly when the update was installed through terminal or some other mechanism?

  • 1
    Can I encourage you to ask a separate question to look into the performance issues? If you choose to do so, please include specific examples and relevant screenshots from Activity Monitor.
    – nohillside
    Commented Apr 23 at 5:36
  • @nohillside Yes I might, though I am trying to see if downgrading actually fixes the problem.
    – mushroom
    Commented Apr 23 at 6:34
  • @nohillside I figured out the issue and some workarounds: github.com/pytorch/pytorch/issues/122394 It is unresolved and an Apple engineer is looking into it. I am experiencing a 10x slowdown in certain GPU operations (something that took 6 seconds is taking 60 seconds). There are some less than ideal work arounds to speed it up while I wait for them to figure it out. Not sure it is worth posting another question since I've identified the issue. Also if I need to downgrade, 14.3.1 looks good enough (though I think I am just going to wait since it is being looked into)
    – mushroom
    Commented Apr 23 at 10:40
  • Assume people impacted by the issue will find it on GitHub anyway.
    – nohillside
    Commented Apr 23 at 11:17

2 Answers 2


These are tracked.

Look in System Information >> Software >> Installations.

System Information

  • 1
    Great thanks! Accepted. It appears I cannot actually go back to the old OS using just time machine, but that is a separate issue that I will ask about in a different question.
    – mushroom
    Commented Apr 23 at 2:49

Here's a programmatic method for use in a Terminal. It relies on jq being installed to parse the JSON output (a common utility that can be installed with brew install jq):

system_profiler SPInstallHistoryDataType -json |
jq -r --arg v $(sw_vers --productVersion) '
.SPInstallHistoryDataType |
map(select(._name|test("^macOS \($v)")))[-1] |
.install_date |
strptime("%Y-%m-%dT%H:%M:%SZ") |
strftime("%a %Y-%m-%d %-I:%M:%S %p")'

Example output on my 14.4.1 system:

Mon 2024-03-25 6:57:07 PM

If you don't need to reformat the ISO8601 date provided by system_profiler, you can remove the strptime and strftime commands at the tail end of the jq program to shorten it. Example output:


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