I have a Macbook Pro 2015, which I mainly use for some light-weight coding and webbrowsing. It has unfortunately, for a long time, been incredibly slow.

I read this solution posted here about replacing the kext files. However nowhere on the internet I can find an answer as to how to replace KEXT files on a legit macos install. Could someone inform me on how to obtain the El Capitan KEXT files and where to locate the KEXT files in Monterey so I can replace them?

I have realised for a long time that my Macbook is extremely slow. It is not even possible to watch a youtube video on 720p without it causing lagging or other issues. I never really had issues with this before as I was not using the laptop often. However, due to circumstances I tend to use it a bit more lately and hence was looking for a solution, as the extremely slow speeds are not in line with what I am used to from this laptop. I tried reinstalling the OS multiple times, but without any results (there is literally only microsoft office and google chrome installed on that laptop at the moment).

I did some research and noticed a lot of people are facing this issue, and the issue is not there with MacOS El Capitan. I also vaguely remember that the speed issue indeed arose after an update back in the day.

I thought about just installing El Capitan, but since it is no longer supported assume that applications will no longer be supported for that OS. That is what led me to the story with the KEXT files. From my understanding of the linked post, the bug is in how the newer drivers operate with this specific Macbook. I was hoping that by reverting back to these old files, I would be able to gain some increases in speed on my Macbook.

Another alternative I am considering if nothing comes from this is to order an m.2 + adapter for the Macbook and installing Linux on that, however I would like to not incurr many costs as I am only using the laptop around 1 to 2 weekends a month. Hence the rabbit hole I went down.

I hope this clarifies the situation and provides the requested additional information

  • Please clarify your specific problem or provide additional details to highlight exactly what you need. As it's currently written, it's hard to tell exactly what you're asking.
    – Community Bot
    Commented Jul 3 at 16:31
  • 1
    I'd need more evidence to be convinced of the narrative in that linked post. I had a 2015 MBP, and didn't observe any problems. Either way, I don't think you can replace system kexts in Monterey at all.
    – benwiggy
    Commented Jul 3 at 17:46
  • Are you able to install macOS on an external drive and find the file named IOPlatformPluginFamily.kext? That’s what it takes to replace a KEXT. Also, please confirm you have 100% backup and know how to restore files if your Mac never boots again before you start this.
    – bmike
    Commented Jul 3 at 18:40
  • @bmike thank you for your responses! I hope the additional information helps create further understanding of the situation. I would be okay with reinstalling El Capitan on this laptop in order to obtain the .kext file. I have tried to google as to where this is located. I believe it is the /System/Library/Extensions folder. I could then indeed backup the current drive, install High Sierra (as I understand that is the last kext supporting OS) and replace them there after installing? What do you think?
    – Shandorius
    Commented Jul 3 at 21:44

1 Answer 1


Apple deprecated KEXT in macOS 11 (Big Sur) and macOS 12 (Monterey) continued the move away from KEXTs:

Deprecated Kernel Extensions

System extensions on macOS Catalina 10.15 or later allow software, such as network extensions and endpoint security solutions, to extend the functionality of macOS without requiring kernel-level access. As part of our ongoing effort to modernize the platform, improve security and reliability, and enable more user-friendly distribution methods, kernel extensions have been deprecated. Starting with macOS Big Sur, macOS releases no longer load kernel extensions that use deprecated kernel programming interfaces (KPIs) by default.

  • This is true in general, but the OP is asking how to take the exact same extension and back port an older version on a newer build. (Although a clarifying edit on the post might help us all agree what’s actually being asked)
    – bmike
    Commented Jul 3 at 18:57

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