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

There's something... 390 megs on boot in 32-bit, and 460 megs on boot in 64-bit

@eww

Why in the world would the kernel allocate more memory than it needs? There would be no tangible performance benefits for over-allocating, especially when the kernel isn't doing any complex, high speed math.

Add me to the list, I wrote a hourly workaround here: http://www.icoretech.org/2011/07/how-to-recover-memory-on-mac-os-x-lion-for-free /

@masterkain_it

Running purge hourly just frees "inactive" memory, and sometimes a little "active". I use this command all the time, but it doesn't fix the problem with kernel_task. It also causes a freeze for a few seconds whenever used.

wyager wrote:

@masterkain_it

Running purge hourly just frees "inactive" memory, and sometimes a little "active". I use this command all the time, but it doesn't fix the problem with kernel_task. It also causes a freeze for a few seconds whenever used.

True, but so far I haven't been able to find any other solution to the kernel_task issue. I think it's just the way it is designed. In any case I purchased 8GB of RAM few minutes ago, hopefully all should be fine again.

But adding more RAM doesn't really fixed it.

The kernel_task used (with 8 GB RAM) yesterday over 1 GB RAM.

And normally it is around 900 MB.

I don't pretend to understand the workings of the kernel, but it has been true ever since the 1980s that the more RAM you install in a Mac, the more RAM the operating system claims for its own use. I suspect that just as every version of Mac OS X has a minimum RAM requirement but runs better with more than the minimum, the kernel task at the heart of the OS probably has a minimum that it can get by with, but is happier with more when it can get it.

Try to disable "Auto resume".

It seems that the ram usage is now no longer so extreme, like before.

That doesn't do anything for me. I already disabled it, auto resume is annoying as ****.

@eww

I noticed my kernel task running around 700MB, but I concur with what you've repeatedly said throughout this thread. I find no preformance issues. I just upgraded to 8GB of RAM kt using 700MB of real mem. I'm not complaining. I Googled kernel task and found this thread. I think if there are no performance issues with kernel task consuming a lot of RAM then this would appear to be normal behavior. Of course as you said the more RAM you install the more the OS will consume with no performance issues. Macs allocate whatever RAM it's need in an optimal way for performance. Always enjoy your input.

Joseph

@MacJoseph @eww OK, I absolutely do not understand either of your lines of reasoning.

If kernel_task benefited from 900 megs of RAM or whatever it shoots up to when you install more RAM, why aren't ours running painfully slowly? It's not like k_t suddenly starts doing more things when you install more RAM.

Why isn't k_t doing the same thing on other apple products? If k_t can run on under 200 megs on another apple product, why can't it do the same on these particular MBPs?

What could a non-buffering process possibly stand to gain by claiming RAM it doesn't need? K_t is not doing any heavy math, storing any significant amounts of data, or doing anything else that warrants using 500+ million bytes.

"Macs allocate whatever RAM it's need in an optimal way for performance."-This is absolute BS. First, the Mac does nothing of the sort. It's up to the process to allocate or deallocate RAM as needed, not the computer. Second, OS X RAM management is definitely not great. The OS would often rather create virtual active memory than deallocate real inactive memory

Does anyone have a shred of proof that performance actually does go up with more RAM consumption? All I've heard so far is guesswork.

I got a refurbished 15" 2011 Macbook Pro yesterday, the 2.0 Ghz model, and this was pretty much the first thing I noticed — I opened up Parallels and it ran sluggishly, so I checked the Activity Monitor and noticed that kernel_task was eating 1GB of RAM. Quitting out of Parallels reduced the amount to about 500 MB, and from a cold boot it's about 450 MB. But on reflection, I'm wondering — is it perhaps the RAM that's set aside for the integrated GPU? That uses system memory, doesn't it?

My old computer — a 2.2Ghz Santa Rosa era Macbook Pro — never used anywhere this much memory for kernel_task, but then, it had a discrete GPU only.

My old macbook had an integrated GPU, I never even noticed kernel_task and I always sorted processes by RAM or CPU. So I doubt it. If it is, though, that usage should go away once the discrete GPU is used...

I've been thinking about the same a few days ago.

I will use in the few days the AMD Radeon HD 6490M.

Doesn't help. Stillt the same size 😐

I am having the same issue. And a clean install of Snow Leopard a few months ago did not solve the issue at all. The memory usage of kernel_task was about 700MB up on boot.

Now I am running Lion, it is over 900MB upon boot. This is ridiculous. Also Safari is a RAM hog as well. Pretty fast I run out of memory even though I have 8GB of RAM.

I am not sure whether there is something wrong with Mac OS X but this is definitely affecting other program's performance.