11-30-2008, 06:40 PM

hi

i am experiencing an intermittent problem with my macbook air, with kernel_task taking up most of my CPU. i have done some research and found that the most common cause of this is overheating, and indeed i am well aware of overheating issues. i have already had parts of my macbook air replaced because of one of the cores locking up and apps freezing. since the repair all worked well for a few weeks and now i am getting the kernel_task problem intermittently. it doesn't seem to be dependent on the temperature (CPUA is around 62 degrees) and the problem comes and goes at this temperature. the macbook air is not freezing as before and i get the problem even when no apps are running.

i have also heard that this problem can be experienced with USB peripherals, but all i have connected is an external hard drive and the problem remains after this is disconnected.

so, basically i am wondering if there is a way of pinpointing what is causing this problem, using the info in console perhaps. i don't know whether i should be trying to install coolbook, taking my macbook air for a replacement, or trying something else.

i would be grateful for any advice

thanks

nick

03-25-2009, 12:40 PM

I noticed this once on my MBA with SSD which is 3 weeks old. I shall be watching it carefully and will be interested to read anything here.

03-26-2009, 05:12 PM

Its the Air overheating.
I had the same problem while traveling in hot countries, where the Air was having the kernel_task eating up all the CPU.When I came back to UK all was OK, as the weather is significantly cooler here, hence the laptop was not overheating.

My conclusion around the Airs power management is:
1. If the processor is idle/the heatsink is cool the processor can scale to 1.6ghz
2. When the heat starts building up, the processor throttles to 800 MHz all the time
3. If step 2 doesnt cause the heating up to stop, then the OS is causing idle loops in the processor via the kernel (hence appearing that its consuming 100% of the CPU whilst its actually preventing the CPU from doing anything).

I couldn;t get mine to stop doing this when in hot climates, hence sold it and bought a Unibody MBP that is much cooler and never overheats...

09-06-2009, 02:45 PM

i'm in palermo/italy since 3 weeks and i also experience kernel_task eating up to 160% of cpu. really annoying. system stalls. beachball all the time.

is this really the heat?

changing book is no option, first i need the light weight. i live out of my suitcase and cant drag heavy equipment.

09-12-2009, 11:56 AM

Hi there

This is definitely a heat issue. I have an Air for 18 months now and have been having this issue since the beginning, whenever it is really hot in the room or when I use lots of CPU, when watching youtube videos for instance.

I have found a solution that works really well, even if it is hard to set it up when you are on the move.

I have 3 ice packs in the freezer and put one under the Air when I watch a hd movie or play a game. This works really well. Of course it s a bit of a do it yourself, but it s inexpensive and efficient. I put a towel under the ice pack to avoid condensation. The other good point is that because of the aluminium body the keyboard becomes really cool, and your hands as well

09-14-2009, 07:01 PM

I got my MacBook Air early August and and started trying to use it it hampered by this strange Kernal Task issue. At the request of Apple Care I did multiple captures and complete re-instals of the OS including Snow Leopard when it came out. After the most recent delays I demanded a replacement.
After all, how could a computer, loaded with ONLY Apple OS, running ONLY Apple Safari, become virtually unusable? You type and it take 10s of seconds to appear. I can't be expected to be an adjunct of Tech Support unable to load my aps to use the computer lest it be a non-virgin.

Apple repair depot was UNABLE to find a hardware problem. I was told by Apple Care that in the end, engineering might say that this is NOT a malfunction at all???? And I just have to live with an unusable computer.

Finally, I argued my way to a replacement through Customer Care. I really hope it works because I think these are great machines when functioning.

I will post when I have the results of the new machine!

11-14-2009, 09:34 PM

Originally Posted by lagunab

I will post when I have the results of the new machine!

Hey, how'd the replacement machine go?? I'm having the same kernel_task / overheating problems on my MBA too.

01-03-2010, 02:38 PM

Same issue for me. I must say that I'm really disappointed. This is my first Mac and I love it, but this overheating issue is bad. I saw in console.app that my time machine mist a back up because of overheating.

Here is the log:

1/3/10 8:29:46 PM com.apple.backupd[3234] Not starting automatic backup due to thermal level

01-03-2010, 11:11 PM

it's improved if you use a laptop stand with a fan built in. no more lags not very mobile tho

08-20-2011, 07:20 AM

Hi Nick,
have had the exact same problem. i believe one solution is
to get the smcFanControl. Kernel goes crazy when e.g. web site plays flash, or ambient temp is hot, or both. Tuning the smcFan application to higher fan speeds lowered kernel by 100%...
Good luck

Originally Posted by nick_harambee

hi

i am experiencing an intermittent problem with my macbook air, with kernel_task taking up most of my CPU. i have done some research and found that the most common cause of this is overheating, and indeed i am well aware of overheating issues. i have already had parts of my macbook air replaced because of one of the cores locking up and apps freezing. since the repair all worked well for a few weeks and now i am getting the kernel_task problem intermittently. it doesn't seem to be dependent on the temperature (CPUA is around 62 degrees) and the problem comes and goes at this temperature. the macbook air is not freezing as before and i get the problem even when no apps are running.

i have also heard that this problem can be experienced with USB peripherals, but all i have connected is an external hard drive and the problem remains after this is disconnected.

so, basically i am wondering if there is a way of pinpointing what is causing this problem, using the info in console perhaps. i don't know whether i should be trying to install coolbook, taking my macbook air for a replacement, or trying something else.

i would be grateful for any advice

thanks

nick