10 Replies Latest reply: Apr 3, 2014 7:57 PM by ReHkO
SanC83 Level 1 (0 points)

Hello, I have a total of 4 GB RAM on my Macbook Pro, and I'm running the latest OS X version 10.8.3. I noticed that my kernel_task process consumes around 1GB real memory, resulting in RAM being maxed out when I'm running only a few other common applications such as Safari, Mail, Word, PowerPoint, etc. Is that normal? Does the kernel_task application typically use such a large RAM space?

MacBook Pro, OS X Mountain Lion (10.8.3)
  • mende1 Level 10 (92,186 points)

    Welcome to Apple Support Communities


    It's a known problem in Mountain Lion. Read > http://www.rdoxenham.com/?p=259

  • Kappy Level 10 (265,907 points)

    As I read that article I don't think it applies to the OP's statement. The article appears to be a possible fix for an out of control kernel_task that consumes large amounts of CPU time as opposed to the OP's statement that it is using a lot of memory. This is not really a problem that the article will fix. I'm not sure it even is a problem. Most users reporting information about the size of the kernel_task seem to have numbers around 1 GB, more or less, in Mountain Lion. Mine is just under 1 GB. I run mostly the same applications as the OP.


    I think the OP's problem is he's running too many applications concurrently, and is too low on memory for the number of concurrent tasks. He may just need more RAM. My computer has 12 GBs of RAM. I have turned off the dynamic pager, yet I have more than enough free memory. However, this machine would choke if it only had 4 GBs of RAM.

  • Linc Davis Level 10 (192,472 points)

    RAM being maxed out


    What exactly do you mean?

  • SanC83 Level 1 (0 points)

    I mean my free system memory gets to zero, with a lot of page outs. I may be wrong, but does all this suggest that I should upgrade my RAM? And it seems that kernel_task at around 1GB is normal, right?

  • Kappy Level 10 (265,907 points)

    Add more RAM. I would say you don't have enough for all the concurrent applications you run. Or, don't run as many applications concurrently.

  • SanC83 Level 1 (0 points)

    Ok, thanks!

  • Linc Davis Level 10 (192,472 points)

    Your problem is excessive swapping of data between physical memory and virtual memory.


    That can happen for two reasons:


    • You have a long-running process with a memory leak (i.e., a bug), or
    • You don't have enough memory installed for your usage pattern.


    Tracking down a memory leak can be difficult, and it may come down to a process of elimination.


    In the Activity Monitor application, select All Processes from the menu in the toolbar, if not already selected. Click the heading of the  Real Mem column in the process table twice to sort the table with the highest value at the top. If you don't see that column, select


    View ▹ Columns ▹ Real Memory


    from the menu bar.


    If one process (excluding "kernel_task") is using much more memory than all the others, that could be an indication of a leak. A better indication would be a process that continually grabs more and more real memory over time without ever releasing it. Here is an example of how it's done.


    The process named "Safari Web Content" renders web pages for Safari and other applications. It uses a lot of memory and may leak if certain Safari extensions or third-party web plugins are installed. Consider it a prime suspect.


    If you don't have an obvious memory leak, your options are to install more memory (if possible) or to run fewer programs simultaneously.


    The next suggestion is only for users familiar with the shell. For a more precise, but potentially misleading, test, run the following command: 

    sudo leaks -nocontext -nostacks process | grep total


    where process is the name of a process you suspect of leaking memory. Almost every process will leak some memory; the question is how much, and especially how much the leak increases with time. I can’t be more specific. See the leaks(1) man page and the Apple developer documentation for details.

  • SanC83 Level 1 (0 points)

    Thanks. This is really very helpful, Link.

  • felipetrovador Level 1 (0 points)

    Hi everyone!


    Searching and searching everywhere, I've probably found the explanation for this problem:




    The Intel HD 4000 graphic card consumes up to 768Mb from RAM. That's why kernel_task is using this amount of memory.


    Hope this helps.

  • ReHkO Level 1 (0 points)

    Use this at your own risk. It worked for me.


    Basic Procedure:

    1- Click in the apple logo on the upleft corner, select "About This Mac".

    2- Click in "More Info".

    3- Click in "System Report".

    4- Take note of "Model Identifier".

    5- Create a new folder called "Recovery_Kernel_Task".

    6- Select Macintosh HD/System/Library/Extensions/IOPlatformPluginFamily.kext

    7- Click the mouse right button at that file and select "Show Package Contents"

    8- Open the folder Contents/Resources.

    9- Look for the Model Identifier in step 4.

    10- Move the file to the folder you've created, if you need to restore the file.

    11- Check the folder in step 8 has 49 files instead of 50 (original files).

    12- Restart the computer and be happy!