SONOMA 14.4 Kernel_Task CPU usage extremely high

I have a 2019 27" iMac with SONOMA 14.4 OSX updated a few days ago.

And I think the issue start to occur after the update.

My Kernel_Task would consume my CPU load up to 60-70%.

Restarting my iMac would flush the memory and everything will be back to normal until I open up any programs like Safari or Adobe Bridge or Photoshop.

The issue would persist even after I closed the program for 30 minutes; Kernel_Task would run high.

If no program is opened, everything would be fine.

I have tried a few trouble shooting method, including creating a new account, did a disk First Aid, the issue would persist.

While the only most affective method is to put my iMac to Sleep mode, it would seem to flush the memory and my CPU load would be back to single digits until I open up another program, the the problem would come back.

I felt this is a bug in SONOMA 14.4 perhaps? Because I think I have experience similar issues before until a new OSX was released.

Does any one have similar issues? or any suggestions?

iMac 21.5″, macOS 10.14

Posted on Mar 24, 2024 5:41 AM

Reply
Question marked as Top-ranking reply

Posted on Apr 11, 2024 7:32 PM

Issue finally resolved, but here is the brief recaps.

Before I installed SONOMA 14.4 my iMac 2019 was running perfectly fine.

I only have Adobe Photoshop and Lightroom Class running, and occasionally watch Netflix or run some FB games.

Because I do run process a lot of stuff through Adobe from time to time, so I would have my Task Monitor open at all time to monitor my CPU or Memory pressure.

Immediately SONOMA 14.4 was installed, I noticed when I run FB game “Kernel_Task” would run over time, but I do not detect any fan noise.

I Googled up what “Kernal_Task” is, I found out it is a program that controls the cooling fan. So I noticed my iMac would get really hot by touching the back of my unit.

I tried to restart or even shut down to let it cool for a few times, it didn’t work, “Kernal_Task” will stay running extremely high, and my iMac hot.

Until I finally realized if I put it down to “Sleep Mode” it would reset the “Kernel_Task” issue, but it only resets it, not fix it.


I followed the instruction from Apple Online Help from an advisor, I have ran it through Safe Mode, and eventually format the whole thing with a fresh clean MacOS the issue still persist. So finally I contacted Apple Support again, they advise that I need to contact a Senior Advisor, and which lead to an appointment to bring my unit in for a physical check up.


At the check up, they determined the fan is faulty, and it needs to be replaced.

After a week and some money spent, I got my unit back, restarted it via TimeMachine, ran a few test to and so far it looks like it is working fine now. It still runs a bit hot, as I can still feel quite a lot of heat venting from the unit, but at least the Kernel_Task is not running at 70% of my CPU.

I think my situation was, the update somewhat killed my fan, so instead of notifying me what could the the issue, SONOMA is running over time try to initiate the fan.


I am happy I was able to fix it, but I still think that SONOMA 14.4 some what trigged the problem.


The point I wanted to make is, I have very simple and clean Mac setup. I kept plenty of space available on my HDD, I don’t have any VPN, Mac Cleaner program installed, that could cause the problem. I have unplugged all external Hub, printer accessories during my trouble shooting, so it was not caused by fault external devices.


Possible cause of the issue combining my personal experience and what I found online with who has similar issue, and spoke to people with the same issue:

  1. Updating to SONOMA 14.4.1 “could” fix the issue. My friend had the same issue on his MacBook with M1 chip, after updating to 14.4.1 it is fixed.
  2. SONOMA 14.4 is a massive update, so it requires a lot of CPU processing, which probably triggered the overwhelming work on my fan, and eventually killed it. This is my case. So the only solution is to replace the fan.
  3. SONOMA 14.4 has many compatibility issues with either hardware of software, which cause some kind of conflict in programming, and SONOMA is stuck at a loop trying to correct it.
  4. SONOMA 14.4 is not an efficient MacOS, it requires a lot of more CPU usage, or cause more hardware heating, so if you have an older unit, either the fan needs cleaning or the fan is not working efficiently, the program is unable to resolve the issue by software correction, instead it is telling the fan to run faster, harder, but in this vicious cycle, it just cause your computer to run even hotter until something fails. So probably the best solution is to get your unit cleaned up or get a hardware check, because your fan is probably dying or dead.


I still think the culprit is SONOMA 14.4, and maybe as a conspiracy Apple is trying to force you to upgrade to a newer unit, or maybe Apple has just got more MS and releasing more half baked software and have the consumer to test their program for them. I can’t really say, but for the future, I will definitely delay my updates unless it is totally necessary.

In the past, I had faith with Apple, updating whenever I could, and never had an issue, and my iMac could usually last for 5-7 years with no problem.

Surely, with more program update, and especially with AI advancement, my computer is running much slower as it would be in the past, but it would still be useable. I mean, I was still using my 10 year old MacBook Air during my iMac downtime.

Apple do make good products, and I love their eco system, that’s why I have not switched, but I would be cautions with their updates now, since I don’t know wha it’s their business strategy now a days.


And most importantly, do make Backup frequently, TimeMachine is still one of the best backup system I have every seen. My system was 99% functional, with only the exception of Loupedeck require re-installation.

I already was prepared for the worse case scenario I would need to get a new unit, but with my TimeMachine backup, at least I would still have all my work in tack.

42 replies
Question marked as Top-ranking reply

Apr 11, 2024 7:32 PM in response to DsTg1015

Issue finally resolved, but here is the brief recaps.

Before I installed SONOMA 14.4 my iMac 2019 was running perfectly fine.

I only have Adobe Photoshop and Lightroom Class running, and occasionally watch Netflix or run some FB games.

Because I do run process a lot of stuff through Adobe from time to time, so I would have my Task Monitor open at all time to monitor my CPU or Memory pressure.

Immediately SONOMA 14.4 was installed, I noticed when I run FB game “Kernel_Task” would run over time, but I do not detect any fan noise.

I Googled up what “Kernal_Task” is, I found out it is a program that controls the cooling fan. So I noticed my iMac would get really hot by touching the back of my unit.

I tried to restart or even shut down to let it cool for a few times, it didn’t work, “Kernal_Task” will stay running extremely high, and my iMac hot.

Until I finally realized if I put it down to “Sleep Mode” it would reset the “Kernel_Task” issue, but it only resets it, not fix it.


I followed the instruction from Apple Online Help from an advisor, I have ran it through Safe Mode, and eventually format the whole thing with a fresh clean MacOS the issue still persist. So finally I contacted Apple Support again, they advise that I need to contact a Senior Advisor, and which lead to an appointment to bring my unit in for a physical check up.


At the check up, they determined the fan is faulty, and it needs to be replaced.

After a week and some money spent, I got my unit back, restarted it via TimeMachine, ran a few test to and so far it looks like it is working fine now. It still runs a bit hot, as I can still feel quite a lot of heat venting from the unit, but at least the Kernel_Task is not running at 70% of my CPU.

I think my situation was, the update somewhat killed my fan, so instead of notifying me what could the the issue, SONOMA is running over time try to initiate the fan.


I am happy I was able to fix it, but I still think that SONOMA 14.4 some what trigged the problem.


The point I wanted to make is, I have very simple and clean Mac setup. I kept plenty of space available on my HDD, I don’t have any VPN, Mac Cleaner program installed, that could cause the problem. I have unplugged all external Hub, printer accessories during my trouble shooting, so it was not caused by fault external devices.


Possible cause of the issue combining my personal experience and what I found online with who has similar issue, and spoke to people with the same issue:

  1. Updating to SONOMA 14.4.1 “could” fix the issue. My friend had the same issue on his MacBook with M1 chip, after updating to 14.4.1 it is fixed.
  2. SONOMA 14.4 is a massive update, so it requires a lot of CPU processing, which probably triggered the overwhelming work on my fan, and eventually killed it. This is my case. So the only solution is to replace the fan.
  3. SONOMA 14.4 has many compatibility issues with either hardware of software, which cause some kind of conflict in programming, and SONOMA is stuck at a loop trying to correct it.
  4. SONOMA 14.4 is not an efficient MacOS, it requires a lot of more CPU usage, or cause more hardware heating, so if you have an older unit, either the fan needs cleaning or the fan is not working efficiently, the program is unable to resolve the issue by software correction, instead it is telling the fan to run faster, harder, but in this vicious cycle, it just cause your computer to run even hotter until something fails. So probably the best solution is to get your unit cleaned up or get a hardware check, because your fan is probably dying or dead.


I still think the culprit is SONOMA 14.4, and maybe as a conspiracy Apple is trying to force you to upgrade to a newer unit, or maybe Apple has just got more MS and releasing more half baked software and have the consumer to test their program for them. I can’t really say, but for the future, I will definitely delay my updates unless it is totally necessary.

In the past, I had faith with Apple, updating whenever I could, and never had an issue, and my iMac could usually last for 5-7 years with no problem.

Surely, with more program update, and especially with AI advancement, my computer is running much slower as it would be in the past, but it would still be useable. I mean, I was still using my 10 year old MacBook Air during my iMac downtime.

Apple do make good products, and I love their eco system, that’s why I have not switched, but I would be cautions with their updates now, since I don’t know wha it’s their business strategy now a days.


And most importantly, do make Backup frequently, TimeMachine is still one of the best backup system I have every seen. My system was 99% functional, with only the exception of Loupedeck require re-installation.

I already was prepared for the worse case scenario I would need to get a new unit, but with my TimeMachine backup, at least I would still have all my work in tack.

Apr 7, 2024 6:45 PM in response to DsTg1015

Latest update.

Apple came back with the inspection and confirmed my cooling fan is bad, and a replacement fan should fix the problem.

I will see when I get it back this week.

But still, I think the SONOMA 14.4 triggered the kill on my fan, because overheating and fan on all the time with MacOS SONOMA is all over the internet.


As far as I could suggest is that, if you hear you kernel_task is high, but you do not hear the fan running high, you better go to Apple to check your fan, because your fan might be dead, so instead of end up with a burnt CPU, I think it's cheaper to get it repaired.

Other than that, format, reinstall, update to SONOMA 14.4.1 or even down grade, seem to fix some of the user's issue, but I do see someone with 14.4.1 start to have overheating after update.


I don't know what is the real cause, although I think it is SONOMA, but these are just the fix I see on the web that might help.

Jun 4, 2024 4:20 PM in response to CABKNY

  • Do you have a Trading View extension installed on Safari or is Safari open to that page?
  • Are you seeing high network usage when using the Network tab in Activity Monitor?
  • Is Time Machine currently performing a backup or failing to backup?


I would suggest posting the free EtreCheck report using the Additional Text option when posting. It will not provide any personal information, but will show what is running on your computer even if you have not launched any apps. It may also provide some insight if there has been any Kernel Panics reported recently.

Using EtreCheck - Apple Community

Jun 17, 2024 8:44 AM in response to etresoft

You're a genius. My iMac is silent rn in the first 50 mins of use without the dongle. Absolutely silent. 0% CPU, kernal task 2.1%, cpu timeon the kernal task is back to ) from when the dongle has been removed so it's at 50.11! Which is a very positive correlation! Kudos sir!


Solve: I detached the HooToo video dongle (currently sold out/unavailable on Amazon) and just rebooted. Ordered mac video extension. Will report back.


I'm going run some more tests right now for performance, but I'd say the overall "feel" of the computer is "mint".


I really appreciate this, I can't afford to "fix" this right now. Best.

Jun 20, 2024 5:20 PM in response to CABKNY

UPDATE.


So I'm back up and running for now, but it doesn't feel 100% stable as I had a kernel_task flare up mid-day, however now is calm. So a few notes to those out there dealing with this immensely frustrating bug.


IMMEDIATE FIX:


  • NO USB/USB-C connections and the iMac runs fine. If you have a kernal_task / CPU issue, disconnect everything, hard reset should get you to square one to further assess issues.


So as long as you don't need external monitors or anything connected to your iMac and you're reading this, thats the current fool proof solve. I have every program on my mac running with YouTube.tv, Netflix, Podcasat app, Apple TV, Notion, etc and stock trading software running and "kernal_task" is at 4.2% and the computer is silent. This is at a 3 hours test. NGL, it's pretty frustrating seeing this test pass and know that this is entirely a new OSX update causing a hardware issue (USB/HDMI/USBC). To think that was not quality assured is another example of how Apple is no longer Apple.


CLEANING:

Clean your iMac thoroughly, vacuum vents, ram area, air dust everything etc. If you have a protective cover around your iMac make sure it doesn't cover the bottom vents. I detailed every inch I possibly could of my iMac. I will say I work in a sun room, and my bottom iMac vents weren't very dirty/dusty, but did have more junk than I expected when I used a DustBuster with a long thin nozzle to clean them.


OS X:

Delete everything in your downloads folder, clean out every cache and application memory log. Now, most forums and solves I found on the internet said to Reset everything on your iMac, PRAM, NAM. I did not do this, just a hard restart, and through detailed physical cleaning. I do plan to do do these resets however, just providing as much context as possible.


TESTS:

Base case: My setup is an 3.6 GHz 10-Core Intel Core i9 iMac, 128 GB 2667 MHz DDR4, with two monitors, an LG via USB-C, and Samsung via HDMI. Both monitors are fairly new. LG is brand new like 2022. Samsung is like 2020. I initially had them attached via a cheap dongle to USB-C. As everyone else on this forum, once I installed Sonoma, that was it. " kernel_task " pain. Someone on this forum pointed out that the cheap video dongle could be the issue. Here are my tests.


  • Attached Samsung HDMI connector via Apple video dongle (Avd): no issues 2 hours. All programs, streaming video running. No LG monitor attached.


  • with Samsung via Avd HDMI; Attached LG USB-C connector via Avd: Dongle will not recognize monitor via LG USB-C via Avd.


  • with Samsung via Avd HDMI; Attached LG monitor via Apple USB-C Cable via Apple video dongle: Dongle will not recognize monitor via Apple USB-C via Avd.


  • Attached LG USB-C connector direct to iMac, with HDMI connection via Avd: All programs, streaming video running for 2 hours no issues; this setup lead to "kernal_task" flare up mid day. I have since CLEANED and DELETED everything on my iMac per the note above and am stable for now. If I get a kernal_task flare up on this configuration my next step would be PRAM reset path and fresh OSX install, preferably the previous version of the OSX.


So for now, the Avd has calmed my computer down and kernel_task is at 1.6% and I have the HDMI via the Avd and the USB-C monitor directly into the iMac with the factory USB-C from LG, not an Apple USB-C (I see a slight difference in girth re the LG vs Apple USB-C cables. Yes I bought a new USB-C "woven" cable). While I loose the ability to connect anything else to my iMac via USB-C and I'm not even going to connect anything via USB, I don't even want to experience even the slightest instance of " kernel_task " pain. I plan to recharge my phone, keyboard and mouse via laptop.


This bug is so bizarre and suspicious imo, if anyone has any questions, please reply and I'll share any more I can.


Jun 4, 2024 5:34 PM in response to CABKNY

CABKNY wrote:

Same. Totally obnoxious. Sonoma update. I uninstalled all applications, look at this window, I have nothing even running. Yes i've restarted and cleaned my cache, still have CPU time that is constant. Seems very strange that older macs are targeted here.

That is the operating system throttling performance due to a hardware fault. The hardware could be external. The only time I ever experienced this was because of a cheap, 3rd party video dongle. Replaced the dongle and problem was solved.

Apr 2, 2024 8:02 PM in response to DsTg1015

I have formatted, down grade my MacOS, still not fixed.

a friend told me that 14.4.1 which came out days later would fixe the problem, upgraded to that, still no fix.

Eventually I sent it in for repair inspection, they told me my fan is dead.

I will not know if replacing the fan will fix the problem. I’m crossing my fingers now.


The cost and the wait for repair is not really a big deal for me, but I am still suspicious that 14.4 killed my fan.

After all, I have found tons of posts on Reddit, Apple Help Community, the over heating issue is happening across many platforms, iMac, MacBook, MacBook Air, while most complains about over heating or fan is always on that killed their battery (if it is a laptop).

I also came across, I think it is a MacBook M2, that after updating to 14.4.1 starts to have this issue.


I think it is a MacOS bug that triggered the kernel_task program error into an infinite loop, then lead to overheating issue in SONOMA, and in some platforms the problem would persist.


My computer has always been kept quite simple, while majority of the time I only runs Adobe Lightroom Classic and Photoshop, and my drive would kept with over 30% of storage space.

I would kept my Task Monitor running at all time to monitor my CPU and memory load, and before the 14.4 update everything was fine, so I am more concerned it should be an MacOS bug.


Apple really need to fix this.

Apr 5, 2024 9:28 AM in response to DsTg1015

First remove these categories of apps and post the EtreCheck report that was already suggested. There will be no other way to verify any software that is conflicting with your System. This is obviously not a wide spread issue and is related to your particular situation with the software that has been installed. It is not unusual to have extensions installed on your system previously that are no longer compatible with a new version of the OS and will just be migrated over:

  • Cleaners
  • Optimizers
  • Antivirus
  • VPN

Mar 24, 2024 8:13 AM in response to DsTg1015

What you describe could be Lack Of Empty Space on the drive.


It could also be a combination of Processes running in the Background that are consuming a lot of RAM


Download the Application Etrecheck  ( External Link ) directly from the Developer.


The Application is Not a " Silver Bullet "  and is  only a tool to examine the Hardware / Software used on this computer 


This is a Diagnostic Tool that makes no changes to the computer Hardware / Software used on this computer 


The application is free or paid from added features. 


The Report will Not Reveal Any Personal Information. 


Post back the Full Report - copy and paste - >>>> using the Additional Text Icon ( 3rd Icon to last ) <<<<


Lastly - should you decide to use and post the Report now or at a later time, we are willing to have a very close look and offer some insights 

Apr 20, 2024 8:18 PM in response to KoshAlwaysHere

So far the Kernel_Task (the program that manages the cooling fan) has been running at less than 5% at most of the time, and the problem has not occurred again.

But I still believe 14.4 had the issue, and they fixed it in 14.4.1.

Probable cause is the GPU was running too hot, and which requires a lot of cooling, so on an older unit, such as mine, it killed the fan. And for luckier people, they just need to clean their fan, and the problem should not occurred, but that's if they do upgrade to 14.4.1.

Those who still have overheating issue with 14.4.1 is probably because they need to clean their fan or their fan is dying.

Mar 24, 2024 5:53 PM in response to Owl-53

"What you describe could be Lack Of Empty Space on the drive."


Actually I have at least 25% of free space, and I freed up some more thinking it was lack of free space, too.

So I have over 30% of free space on my 1TB drive.

And I had not used more drive space since the issue started, while only thing I could think of is it probably start to happen after I updated to SONOMA 14.4.

I have contacted the Support Advisor, they sugguested running through Safe Mode to see if it persist, if not I'll have to reinstall my MacOS, which I really don't like to do that.

I have searched the web and found that quite a few people on different device has similar problem (search for SONOMA CPU heating issue).

I have seen other solves including stop Refreshing Wallpaper, and restart SMC twice, which I will try to see if that works.

Apr 11, 2024 5:17 AM in response to KoshAlwaysHere

KoshAlwaysHere wrote:

Ditto, same issue.

Different issue. kernel_task usage of 60-70% is some serious operating system problem, most likely caused by 3rd party system modification software.

And over 1000% CPU usage.

This is a hardware failure. The system is throttling the CPU to try to give you enough time to backup your data before you take your computer to Apple for repair. In some circumstanced, the failed "hardware" can be external. The only time I experienced this was due to a cheap VGA dongle from Amazon. I replaced it with an Apple dongle and never had the problem again.

May 2, 2024 4:15 AM in response to DsTg1015

In my work laptop, which is a 2019 Intel chipset Macbook 15", the same issue happened post v14.4.1 upgrade exactly. The day the device was upgraded, I started having issues running my regular office applications in it. After reading this chain, I understood that, yeah I missed that noisy fan sound, that I used to hear earlier rarely.

My laptop is well ventilated, and constantly in the right environment where the room temperature is 30 degrees Celcius or less.

But since it is a work laptop, the office is replacing it with M2, as officially Apple didn't release any notes that suggest that *things* are hitting the fan after upgrading to 14.4.1. But we all know what exactly happened here. In my office, several IT cases were filed, all are the same story, and all are Intel chipset laptops of 2019 or a little later model.

This thread has been closed by the system or the community team. You may vote for any posts you find helpful, or search the Community for additional answers.

SONOMA 14.4 Kernel_Task CPU usage extremely high

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