DChabot

Q: kernel_task consumes a lot of RAM in early 2011 MBP, sometimes Finder too

Hi,

My old MBP3,1 (late 2007, 2.4 GHz Core 2 Duo) worked quite well with 4 GB of RAM, even after weeks without restarting. In fact, I used all available RAM only on some larger analyses using R, which loads the entire dataset in memory. To be able to run these few analyses faster on my new machine (early 2011 MBP), I bought the 8 GB RAM option.

In Activity Monitor, I noticed something strange. Whereas my old MBP shows kernel_taks as using between 100 and 200 MB of RAM, the new MBP uses about 550 MB just after the machine started up and often shows over 600 after a few hours or days of use. A one year old iMac, again Core 2 Duo with 4 GB of RAM, gives a kernel_task memory usage below 200 MB after weeks of use.

I've not been able to find what kernel_task does. Is this amount (around 600 MB, but it has gone up to 800) normal? Is it managiing the additional number of cores that requires this behind the scenes amount of RAM?

Anyway, I now quite often have more than 4 GB of RAM in use even when I have only a few applications running (not even including R!), which surprises me.

Also today, after moving a lot of files back and forth between an external drive and the new MBP, after emptying the garbage can that contained a hefty number of files and doing a first Time Machine backup, the Finder ended up using 2,4 GB of RAM according to Activity Monitor. I have never seen anything like this (although I admit not having Activity Monitor on all the time). Even after the backup was finished and the external drive disconnected (in fact the machine was left idling for a few hours) cpu usage was down to nearly zero, the Finder kept its 2.4 GB of RAM. I restarted and the new RAM usage for the Finder was 26 MB. I have a screen shot showing the 2.4 GB, but I could not find a way to attach it to this message. I can send it by email on request. I don't think this Finder behavior was normal.

Somewhat worried,

Denis

MacBook Pro 2.2 GHz i7, 8 GB RAM, Mac OS X (10.6.6)

Posted on Mar 16, 2011 12:04 AM

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Q: kernel_task consumes a lot of RAM in early 2011 MBP, sometimes Finder too

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  • by Aaronp2k,

    Aaronp2k Aaronp2k Oct 23, 2013 10:34 AM in response to DChabot
    Level 1 (0 points)
    Oct 23, 2013 10:34 AM in response to DChabot

    I can confirm what some of the users are saying about ram automatically being alocated to kernel task. I tried a little experiment, opened safari and kept opening new tabs (so its memory usage would go up) and as I was doing this kernel task would then start reducing its memory usage. So to sum it up, if kernel task is using 500 mb of ram then chances are you have just over 500 mb of free memory, if it uses 300 mb then you have just over 300 mb of free memory. technically this memory is not free, because it is being used by kernel task but theoretically it is free because kernel task does not depend on that memory.

  • by edgarperez,

    edgarperez edgarperez Oct 23, 2013 5:14 PM in response to DChabot
    Level 1 (5 points)
    Oct 23, 2013 5:14 PM in response to DChabot

    Mavericks has made a big change in my kernal, down to 600 MB from a gig.

  • by RunSpotRun,

    RunSpotRun RunSpotRun Nov 1, 2013 2:27 AM in response to DChabot
    Level 1 (0 points)
    Nov 1, 2013 2:27 AM in response to DChabot

    My situation:

    - MBP 2.4 GHz i5

    - 16GB RAM

    - OS 10.7.5

    - Kernal_Task taking up over 7GB of BLOODY RAM!!!

    Why? Fu(ked if I know.

    Solution? See the following link. It worked for me and apparently others as well.

     

    http://www.rdoxenham.com/?p=259

     

    The issue appears that the ******* thing was overheating and this somehow caused the Kernal_Task to take over about half of the total RAM.

    The RAM taken up, appears to be a percentage of the total, not a specific amount, which is why some people are effected more than others

     

    The only thing now is, that YOU are now responsible for ensuring your machine doesn't overheat.

    If you don't, it's probably paperweight time.

     

    Good luck.

  • by Zatixo,

    Zatixo Zatixo Nov 1, 2013 2:58 AM in response to RunSpotRun
    Level 1 (8 points)
    Nov 1, 2013 2:58 AM in response to RunSpotRun

    I had no problem on Leopard and Snow Leopard. I was able to open multiple big photoshop files, 10 other programs at the same time + chrome with 10 tabs.

     

    Since Lion, doing the same, result in OS freeze while the memory was cleaned, just when opening one file in photoshop.

     

     

    The memory management is like broken since OS X 10.7. Like the old days when I was using windows XP and windows Vista.

  • by tyzam1,

    tyzam1 tyzam1 Feb 6, 2014 6:23 PM in response to DChabot
    Level 1 (0 points)
    Feb 6, 2014 6:23 PM in response to DChabot

    FreeMemory. does the job. look it up on the app store. The free version is just fine. I use it on my MBA early 11 (only 2gb ram :`( )

  • by Attila,

    Attila Attila Mar 17, 2014 9:46 AM in response to tyzam1
    Level 3 (610 points)
    Mar 17, 2014 9:46 AM in response to tyzam1

    It doesn't solve the problem, though. Kernel_task should not be much more than 1 GB...

  • by Nauman Mithani,

    Nauman Mithani Nauman Mithani May 20, 2014 3:01 PM in response to Zatixo
    Level 1 (4 points)
    iPhone
    May 20, 2014 3:01 PM in response to Zatixo

    I agree. Memory (RAM) management has been very poor since 10.7. It exists two OS'es later in 10.9 as well.

     

    In the name of keeping some distinction from Windows, please fix this, Apple.

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