Kernel Task Problem (CPU usage way too high)
DragonFruit
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gab1 Posted messages 6366 Registration date Status Member Last intervention -
gab1 Posted messages 6366 Registration date Status Member Last intervention -
Hello,
First of all, I want to inform you that I’m not a computer expert, so I’ll explain my problem as best I can.
For several months now, I’ve been experiencing very high CPU usage by processors that use up to 300% or more of their capacity for kernel task management, I think. I’ve already tried everything I could find on the internet, whether it’s freeing up storage space, special applications, repairing permissions or other actions with Onyx, … I’ve tried everything and I’ve just done a clean install again (reformat and reinstall). But I still have this problem and I’ve tried everything but I don’t understand why the kernel is using so many resources.
What’s even odder is that the %CPU stays at 300% all the time, but from time to time it drops and works normally. But then it climbs again. I’ve disabled Spotlight indexing, FileVault, anything that could be to blame, but I can’t find any solution.
If someone has already had this kind of problem or could point me to where they might help me, I would be overjoyed. Thanks in advance.
Configuration: Mac OS X (10.11.4) / Safari 9.1
First of all, I want to inform you that I’m not a computer expert, so I’ll explain my problem as best I can.
For several months now, I’ve been experiencing very high CPU usage by processors that use up to 300% or more of their capacity for kernel task management, I think. I’ve already tried everything I could find on the internet, whether it’s freeing up storage space, special applications, repairing permissions or other actions with Onyx, … I’ve tried everything and I’ve just done a clean install again (reformat and reinstall). But I still have this problem and I’ve tried everything but I don’t understand why the kernel is using so many resources.
What’s even odder is that the %CPU stays at 300% all the time, but from time to time it drops and works normally. But then it climbs again. I’ve disabled Spotlight indexing, FileVault, anything that could be to blame, but I can’t find any solution.
If someone has already had this kind of problem or could point me to where they might help me, I would be overjoyed. Thanks in advance.
Configuration: Mac OS X (10.11.4) / Safari 9.1
5 answers
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300% capacity? xD What kind of processor is that?
A troll urge is bubbling up to my fingers
I am a naughty troll! -
Hello,
It would be good to specify which type of Mac this problem occurs on, portable or desktop, because I read that this problem happened on a portable Mac, having suffered the drawbacks of liquid damage, could that be what happened previously?
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When it's urgent, it's already too late (Talleyrand) -
Thank you already for your responsiveness and your answers
@Henry
When I talk about 300%, I think it's at the processing level. In total it represents 70% of the system, then 30% remains for the user, so the applications used and the Idle cache I think. Sorry I don’t know much about it.
@Dede
Yes I did not specify my hardware, it’s indeed a MacBook Air 1.7 GHz I7. And as you point out my computer experienced the same thing. I therefore dismantled it completely to assess the damage. Nothing apparent because the keyboard is a good obstacle :/ I had initial problems (power supply issue, black screen, then other issues with the trackpad connector). But nevertheless I’ve always managed to make the computer run optimally.
For example, just now the processor load dropped to 6% and then rose to 70% (on a maximum base of 100%). So I don’t understand why the kernel processes so much information, tasks or operations without me using applications.-
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This is surely possible, but I don’t understand why this anomaly would be random over time rather than permanent. But since I did the formatting and the OS reinstall, it can only be a hardware problem. Do you know of a tool that could truly diagnose all my components, because in the system information I don’t see any obvious issue?
- It could also be a weld on the motherboard that is not reliable.
No, I don't know of any specific tools for this type of check; Apple Authorized Service Providers certainly have some. Is Apple Hardware Test capable of making this type of diagnosis? that is the question but, it doesn't cost anything to try.
https://support.apple.com/fr-fr/HT201257
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Thank you, the problem is that when I start to perform this test, it tells me that my computer is not referenced because I do not have a serial number. I had already noticed this in the "About This Mac" tab. And I don't know where I can provide and enter my serial number. Note, I don't know if this has any impact but I bought this computer in the United States.
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Hello
In the past it could happen to end up with a Mac without a serial number, when the logic board had been replaced. I myself have an iMac G5 that is in this situation, because its motherboard was replaced by Apple. I had pointed this out to Apple. I was told that it was normal because it requires reflashing the ROM memory that contains this number, but that not all Service Providers are equipped to do that. But that was a long time ago. Things have changed for some time now, according to Apple, and today, all Apple service providers are required to replace the logic board with a board bearing the original serial number of the Mac, and that is why service providers receive the replacement board already prepared by Apple, with the serial number. So, today this serial number must necessarily be stored in the ROM of the board.
If this is not the case, it’s because this Mac has undergone an intervention or Apple’s rules, or because it is a counterfeit copy.
Also see these pages:
https://support.apple.com/fr-fr/HT201862
https://checkcoverage.apple.com/fr/fr/
This hardening by Apple follows fraud by certain service providers themselves.
Best regards
PS: regards to dede :)
Have a great day :- ) - Francis
Always indicate your exact system configuration and read the entire answer provided-
Hello Francis,
Thank you for your clarification on this subject. As far as I'm concerned, it is impossible that this is a copy or counterfeit because I bought it at an Apple store at a university, and I never changed any components. Surely with all the manipulations I’ve performed, there must have been a synchronization problem or something like that. I will look into how I can restore the serial number (if that is feasible). -
Hi there, (hello Francis)
I also had this problem of ending up without a serial number on one of my two G5 PMs, following the motherboard replacement, but according to the explanations I received, after an initial replacement with a refurbished, defective motherboard, the second one, surely refurbished as well, left me without a serial number.
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Hi could you run an Apple hardware test and tell me which sensor is faulty.
I don’t have the year of the machine ?? or I didn’t see it.
You cannot replace a keyboard on any Apple machine; some components have firmware in them (not all) to prevent machines from being repaired by non-Apple service providers
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sorry for my spelling :/
apple IOS/OSX certified technician-
Hello, I can't run Apple hardware tests. When I try to start it, it tells me that my serial number is not referenced, so I can't proceed. Yet I haven't modified any computer components and it is definitely a computer from an Apple Store. There shouldn't be any problem, but I don't know how to "re-synchronize" or update the serial number in order to run the Apple Hardware Test.
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