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

I believe that this is realted to the parent of this thread: https://discussions.apple.com/thread/3262080?answerId=16420653022#16420653022

I don't think this is specific to that particular MBP model, but rather an OS issue and is still being seen in newer OS releases.

I have a Mac Server 10.6.8 (2 x 2.4 GHz quad-core xenon) with 32 GB RAM and my kernel_task (64-bit) is using 2.91 GB of real memory (even after a fresh reboot). Is this more evidence that as you add more RAM, kernel_task is going to take up more memory space? BTW, the private memory for this process is 40 MB.

Are you guys taking into account the Virtual Memory that is being used as well? Because that really adds up, and then you get high "page outs" (anything > 100mb is high) and it's really going to slow your machine down.

Fortunately my kernel_task (or unfortunately?) mine is pretty much all active in memory... which means, whatever it's doing, it thinks it's important.

I'm running a mid-2010 MBP with 8gb, 10.6.8. fyi.

Just for everyone's info ...

I just received a 17" MBP with a 2.5Hz i7 CPU this week. Last night I upgraded it by adding a 16G OWC memory kit.

As I type I have 3 users logged in, multiple copies of XCode running, Simulator and Aperture running, mutltiple Tower, Email, Safari and other software all running. Kernel_task is taken 1.08G of RAM and ticking over at about 1.5% CPU, probably due to iStat menus and Activity Monitor. In all, Activity Monitor reports 8.67G of RAM being used.

And it's running beautifully. I was a little concerned at the memory usage of the kernel which is how I got to this thread, but as the machine is still screamingly fast - not that concerned.

So it does appear that the kernel will scale in relation to how much raw RAM you have, based on my results vs others mentioned here.

I have an iMac 27" 3.4GHz i7 and 13" MBA 2.8GHz i7. They are both running 10.7.2. My MBA has 4GB and because I'm running out of memory on my iMac, I just upgraded it from 4GB to 12GB. Now myu iMac is running much much faster. But I notice that the kernel_task uses up much more Read Mem on my iMac. It is at 896.2MB while on the MBA is only 347.4MB. Looking at other process here is what I see

iMac MBA

Firebox 160.9MB 77.4MB

Chrome 83.3MB 44.9MB

MS Word 96.8MB 52.8MB

Excel 79.7MB 39.6MB

I have exactly the same problem. I got a new MBP 2.2Ghz, i7 with 4Gb of RAM. Kernel is around 600Mb. The computer freezes constantly due to lack of memory. My old laptop, a MacBook Pro 2.66Ghz, Intel Core Duo with the same 4Gb of RAM, used to be way faster and this kind of problem never happened. I wish I have never done this upgrade!

Ok, sounds good! Thanks for sharing!

@rodrigocbv - Now that does sound odd. I did a similar thing, I upgraded from a early 2008 pre-unibody Macbook Pro 17 with a core 2 duo at 2.66Ghz and 4G RAM, to a 2011 core i7 @2.5GHz with 4G RAM and then swapped in 16G RAM a week later.

The new machine was noticibly quicker than the old, even with the same memory. Given that memory limits how much you can run at one time without swapping and therefore only effects speed when you reach capcacity, that newer machine should be much quicker. With the way modern OS's work, limited memory will slow a machine by swapping to the hard drive a lot, but not freeze it.

If your MBP is freezing I would suggest that there is a different problem. Freezes are an indicator of a more serious software or hardware problem. For example, in my pre-Apple days I built a new machine which would randomly freeze for no reason. After a couple of days I ran an extensive range of RAM checking sotware which found a bad RAM chip. I replaced the RAM and the machine ran beautifully afer that. I've seen similar things from faulty video cards or miss-matched drivers and hardware.

I would suggest running some extensive diagnostics if you are comfortable dealing with hardware at that level, or take the machine into an Apple store for testing.

Your new MBP should not be freezing up.

@drekka - Thanks for the reply. The machine is indeed faster when there's enough free memory. However, I used to run up to 4 different applications with my old mac without a ANY problem. With the new one, I run the same applications (Skype, Excel, iTunes and Chrome) at the same time but there's not enough memory. The system becomes noticeably slow.

I'll probably increase the memory to 8Gb soon but I find it strange that the performance is worse with a supposidely better machine.

Did you ever get a response to this?

I have 4GB of RAM on my mid 2009 MBP 15 inch.

Kernel_task is eating up 750MB of my RAM, and is about 6GB virtual mem. Why the heck is it taking so much?

Any ideas on how to resolve this please?

I have the same problem since I've upgraged my White Unibody Mid 2010 with 4 GBs from Snow Leopard to Lion.

It seems to be this is the problem of Lion, not of MB model.

Hey cupofnoise, it's not a Lion issue per se — or, at least, the RAM usage that people in this thread are experiencing isn't, because there's plenty of Snow Leopard users amongst them (personally, I'm running Snow Leopard on an early 2011 MacBook Pro). I'm still sticking to the theory that it's the integrated graphics — I installed 8GB of RAM and noticed that kernel_task memory usage went up further afterwards, which seems to make sense as the integrated chip uses more RAM if you have 8GB on board (512MB instead of 384MB).

Integrated graphics may hold the key. Would like to add a voice to this issue which has plagued my early 2011 MacAir Snow Leopard from the outset. Large real memory usage by kernal_task that results in page outs and swapping, even when nothing else is being used and after a restart.

i have a mid 10 mbp that i just increased from 4 to 8gb. everything is running ok but i noticed that k_t is now using 400+mb upon boot and right now with 2 browsers open its tat ~600. before the ram upgrade it wasnt that high, in fact firefox was usually at the top of the list of ram hogs. is it just my os(lion before and after upgrade) taking up more ram in proportion with the increase?

edit**

i honestly don't know what im talking about, just trying to keep my mac healthy 🙂

Yes, it is.