High kernel_task Memory Usage on MBP mid 2012 after 10.8.3 upgrade

Wow! i think i'm kind of in the same situation, i just bought a rMBP 13' (latest 2013) and i'm always kind of paranoid everytime i buy a new pc or whatever. I just wanted to know if it was normal for the kernel_task to have a virtual memory size of 6 gb when my pc is only 8gb ( the real virtual memory size is 465mb but sometimes goes up to 600mb). Also the % CPU varies from 2 to 11 when i open youtube or whatever site with video content (and ONLY safari is open, no other application are).

Another thing that kind of bothers me is that it sometimes lags when i try to change the resolution while having youtube or any page of safari open. It would be really good if someone could answer me (and i dont really want responses like "just restar it"or whatever because i paid a lot of money for something that may or may not be functioning well...)

So is it normal? shoud i change it or what?

PD: it is 100% new i mean like i still have 208GB of flash storage left (out of 250GB)

I have this same issue on my iMac after an upgrade. My girlfriend's iMac (same model) was unaffected. So the problem seems to affect random machines of all ages and types. I have a solution but not a fun one.

I've read *a lot* of forums on this kernel_task problem with people spouting quite a lot of rubbish.

I first tried everything listed on forums: reinstalling OS X, removing kexts (that apparently stop your computer from overheating), new RAM, tidying up the computer. None of it worked.

One guy said he took three trips to the Apple Store, having his MBP sent off each time; eventually they gave him a brand new MBP of the latest spec. That might be the option for you but I didn't want to be without my computer for that time.

Finally, I did a complete wipe of my Mac. If you boot using the backup partition, or using a USB with an OS X Install on it, the option to 'reinstall' or 'install a new OS X' does not wipe your computer. Once it has finished, you will have all your files and applications still. This did not fix my computer. Instead, you must use Disk Utility first to wipe you Macintosh HD partition and then install. Then you Mac acts like it's brand new. Only this fixed the problem. The massive downside is that I had to backup everything and reinstall all my apps.

This is a drastic measure, and you run the risk of forgetting to backup all the stuff you want. It did work though and was ultimately quicker than going to the Apple Store (even if I might have got a new computer out of it).

In summary, to fix this problem:

1. I backed up all my files onto an external hard drive!

2. I booted up to the recovery screen (Command + R or hold the option key at bootup)

2. In Disk Utility, I 'erased' my 'Macintosh HD' partition

4. Back on the main recovery screen, I chose to (Re)install OS X.

Drastic. But it worked.

With safari open on mavericks I have 9.3 gig of memory in kernel task, on closing safari, i have 1.27 gig - this is a recent bug (either mavericks, or more likely safari update)

I've just change Safari for Chrome and my laptop is working better and faster but it becomes really hot...so I've return to use Safari again. For some reason, it's working fine again! Before using the 2 browsers I cleared it all(Historial and cookies).

I fixed this on my machine,. here is how.

Symp:

kernal_task splikes to 397%, 4900%, etc etc etc

Happens 85% of time when plug in Thunderbolt Display

Happens 10% of time just doing nothing

Fix:

Reboot,

hold down OPTION Key while rebooting

Reinstall Mac OS

My OS

OSX 10.9.1

I have the same problem and it's really slowing down my computer

I Had the same problem described since the 1st post and did what whoamawhatsit: reboot and reinstall and now OSX runs amazingly!! Problem's gone! Finally!! I tried everything for weeks!

thanks a lot whoamawhatsit!!

😀

Hmm I have safari listed as a seperate process as well but killing safari lowered my kernel_task memory usage from 6GB to 2GB.

Must be some plugin or something in safari causing the issue.

For any one still seeing the high kernel_task CPU % it is almost always a 3rd party program or extention.

The best thing to do is to do a clean reboot and do not have anything running. Check the kernel task is it ok? then start opeing apps one by one. Once you see the spike you got it. If you get it right off the bat look at the programs or apps that you installed that fire up as soon as osx starts or logs in.

Here is a solution/fix to kernel_task killing memory and CPU issue.

Fixing kernel_task Memory / CPU Problems in Mac OS X

Hope this solves your problem.

Thanks

My model identifier says MacbookPro9,1 and I only have until 8_3. Any ideas?

.

I tried this. Kernel_task memory is not over 5 gb anymore, but memory is still reaching to its maximum. I upgraded from 8gb to 16gb hopping that this will sort the problem. but kernel was going up to the maximum memory available. So it was over 5 gb before I tried your solution. Now kernel is around 1gb but memory still all in use.

Had a similar issue where my Mac would run out of memory and heat up when starting Safari. I launched safari, I selected reset safari in the Safari menu, then quit safari and start safari again. The behavior has been normal since.