Kernel_task on a new MacBook Air

werpu wrote:
The root cause is pretty clear to me. In the first incarnation of OSX for the AIR the kernel task did not exist, but the air started to do core shutdowns due to thermal problems the machine has (or gets after a while), after that Apple issued an update which should get rid of the core shutdowns they were gone, but whenever the machine reaches a certain point of processor heat the kernel task, probably a task pushing idle instructions onto the processor rears its ugly head.

Just cool the machine down while you have it and you can see once the machine cools down the kernel task dissapears...
You do not need an official statement from Apple regarding all this. I had my Air long enough to figure it out myself.
Glad I got rid of this lemon, seriously.

Honestly, that about summarizes it. While I loved the air, I'm glad I got rid of it. Traded it up for a MacBook Pro 15" and I couldn't be happier. I do miss the weight and the 13" screen, but I'll live.

I hope you are wrong and it is not a design flaw. I have AppleCare and I hope they can correct the situation. I'll let you know.

My first generation Air has just seen its third repair in an attempt to fix this problem. The first repair replaced the several components relating to cooling (e.g., fan, daughtercard responsible for the subsystem, etc.), the second replaced the main logic board, and the third has replaced the thermoplast.

I am waiting for the repair shop to confirm that they actually rigorously tested the machine before I bother going in again to find that it is still broken.

AppleCare has stated to me that their policy is to attempt to fix the machine three times before they will offer any other remedy. At this point I'd prefer my money back, or else receive a MacBook Pro in lieu of a new Air, as I no longer trust the design and build-quality of this particular line of Macs.

Good comments. I'll go in a see a Genius about this. Even right now, with three programs open, the Air is hot. CPU at 58 C. Why, oh why?

Here is a little short story, for all us Air users:

Sitting up high, high, close to the clouds. It's night now. Being in the north, things are colder than elsewhere in the world. It's 15 C outside, with a strong wind. I gaze out into this night. There's black everywhere, and specks of light from cookie cutter skyscrapers. I see silhouettes through the windows. Now I wonder: how many of these people are Air users? Is that fire truck speeding down the street going to rescue a family of Air users? Did it get that hot that it burned their apartment down? Is that Doctor, who is making a house call two blocks down, going to treat burn marks on the lap of an unsuspecting Air user?

Uh oh, better not open iWeb, or Photoshop, on the Air, it might burn down an entire city. Imagine, something as thin and light as the Air, able to burn down an entire city. Maybe that's why the military put an order in for 5000 MBAs: it's their new flamethrower. As a matter of fact, there's a newspaper in front of me, and it shows sales projections for MBAs for the rest of this year. It's exactly 5000.

I wonder, wonder... what things are like in the south. I've heard that the Air in those places is red. That the actual skin of the machines in those areas has permanently turned red. I've also heard of people using the Air on camping trips to start camp fires. In fact, as I look up into the mountains, I do in fact see a campfire. With 2.5 hours of battery life, with a heat up to the Sun's Corona level being 2.3 minutes after waking from sleep, that means that a camper, on a fully charged battery, can light about 65 fires waking from sleep.

I really wanted to love you Air. I tried so hard. But all that I am left with is burned off eyebrows and melted fingers.

This is interesting. Apple replaced my thermal module. After that, I have not had kernel_task run crazy. At most kernel_task went to 50%, although I run a lot of high CPU tasks. I don't have enough evidence yet to say I never have a kernel_task problem, but it definitely seems improved. Before, kernel_task would go to 150% and completely slow down the computer. That seems to not happen anymore.

But it is not a clearcut solution. This is second time Apple replaces the thermal module. First time, half a year ago, the kernel_task problem became much worse; I had to buy some cooling pads to even use the computer. The second replacement made the computer perhaps better than it was before the first replacement. Perhaps Apple improved their thermal modules. Or perhaps there just is variation in their effectiveness.

I had this problem for months, and it was finally solved by Apple replacing the logic board.

They first had me format and reinstall SL, followed by replacing the Airport card, which appeared to be causing problems. After neither fixed it, they sent it into to a support center where the logic board was replaced.

It appears that this problem will cause an Apple Hardware Test to generate this error code: 4SNS/1/40000000:TsOP-128.000, and that the only solution is replacing the logic board.

For me this would only happen when I was connected to my external monitor via mini-DVI. Apple reiterated that it's not heat related. If you have this problem I recommend you take it in and have them send it to support HQ.

Good luck.

ahostmadsen wrote:
This is interesting. Apple replaced my thermal module. After that, I have not had kernel_task run crazy. At most kernel_task went to 50%, although I run a lot of high CPU tasks. I don't have enough evidence yet to say I never have a kernel_task problem, but it definitely seems improved. Before, kernel_task would go to 150% and completely slow down the computer. That seems to not happen anymore.

OK, another false alarm. It's just as bad as it used to be. Just running time machine, nothing else, will make kernel_task go to 150%. Of course, this situation is exactly when I cannot use my cooling pad, as the the MBA has only one USB port. It's not only the iPhone 4 that has hardware issues.

What's interesting is that the problem is gone when you log onto the machine under the Safe Boot mode. Is anyone getting the same experience?

I got a BookArc. It's a ridiculously over-priced steel stand with a cosy rubber niche that holds MBs vertically when closed and connected to an external monitor. Upturning my MBA into that baby was a super duper quick fix for that greedy kernel_task blighter.

I was able to fix this and here is how you do it. Turns out it's pretty simple.

http://brunomiranda.com/past/2010/7/26/solvingthe_kernel_task_cpuusage/

Hope that helps.
Spread the love

Take a look here: http://tech.superhappykittymeow.com/?p=258

This solved it for me by removing AppleIntelPenrynProfile.kext or AppleIntelMeromProfile.kext from your system.

Has anyone else has run the Apple Hardware Test from the OSX disc and gotten an error code?

Just copying my reply from another similar thread.

I did try the tip from superhappykittymeow above which makes total sense to me and looks like it have helped alot of people. Unfortunately it did not seem to work. So here is another suggestion just in case.


I just spent a day trying to solve this problem on a revA Macbook Air (core 2 duo 1,66). I found a solution that for now works on this computer, not saying that this is a universal solution for this problem though, but you might want to give it a shot.

Some have suggested that this firmware update ( http://support.apple.com/kb/DL3) for the MB Air might be a part of the problem, especially the core idling part then. But since there is no way (that I know of) to downgrade the firmware from this I cant test this.

I found the original thread when I saw that kernel_task was causing the slow behaviour of the computer. The computer was running 10.5.8 so I decided to first try a clean install of 10.6, but the problem persisted. Then I started the computer from my USB repair disk which is running 10.5.1. While booted to this system and disk the problem was not there, which first made me think that maybe it actually can have something to do with the internal HD itself (although it passed all the tests). But instead I tried installing the same system version on the internal HD as on the repair disk (10.5.1). This now seems to have solved the problem, the kernel_task is under 5% currently, whereas before if was constantly over 100%. I turned off software update to make it stay at 10.5.1, this is of course not ideal but I'd rather have that than the unusable crap the computer was before.

I'll let you know if there is any news on this computers behaviour.

Know there hasn't been much activity on this discussion recently but I just wanted to pass on that, after experiencing months of the same problem of my MacBook Air slowing down, I worked with our tech expert here at work and experimented with different placements of the machine. We notice that cooling/ventilation were critical to keeping the kernal count down and available cpu's up. So we actually placed my machine upside down (with a pad to protect the top of course)on my desk, and the kernal count went from 152 to 38 and available cpu went to 40+ percent. most important, the machine has really cooled off, you can feel the air coming out of the vents that are not topside AND the machine is a fast as when I turn it on first thing in the morning. I of course don't recommend this solution for someone not using a monitor (unless you lie on your back when you use the computer) but with a good monitor it's a shoe in solution. Good luck!
JOM