MacOS Sierra / kernel_task problem

I installed Mac OS sierra yesterday night in my MacBook Air13" (4gb) I also use an external SSD (Samsung T3).


Today I could not do any task because of CPU and ram usages.


First, I thought this is because of new OS, but then I check activity monitor and saw kernel_task use around 50-70% percent of CPU.


I wonder, what it is and how I can fix this problem (I found some entries in the forum, but I am not sure this is the same problem or not).


Thank you.

Replies

kernel_task is the main process of mac. Yosemite and El Capitan users had a problem with the kernel_task as it consumed a lot of memory. When I upgraded to Sierra I noticed that this process task takes lesser memory in comparison to the aforementioned. Closing all the running applications and then rebooting Mac solved the problem for me.

Mac mini 2012


Was using Mac Mini for things like Netflix. Now, the kernel task has been consuming 500-600% CPU when I stream video on Netflix. Tried Safari and Chrome browsers with Netflix streaming and the kernel_task in activity monitor spiked above 500% after initially working. Quitting browsers respectgively brought kernel_task back down after a minute of so. In short it's somehow related to how browsers are using memory, whether it's Netflix or Apple I dunno but the problem just started about a month ago. At one point it seemed to just be the browser(s) being open but it was so spikey I'd have to spend more time to confirm it.


Haven't seen this issue pop up for other items.

I'm having the same problem. I've been using my MacBook Pro (mid 2014, 16GB) for heavy development almost everyday. It's really frustrating not to be able to solve this problem in a timely manner. I used to love the Mac OS and still prefer MacBook to other alternatives, but to be fair seems like Apple doesn't care that much about the users.


By the way, not only does the memory usage look suspicous to me, but also the virtual memory size, 72GB in my case (although probably not being fully used or allocated) .


Also, how do we know this is not a malware of some sort? Any info or help would be appreciated.

This is probably not a malware, because reformating the SSD and reinstalling operating OTA did not fix the problem for me.


Please file a bug, if you didn't already. I filled mine in Aug 2016.

I just upgraded to Sierra 10.12.3, but I started having this same problem when I upgraded to Sierra.

I did everything that was suggested in this thread, but still the problem is there.


I have an asus PB278 connected to my macboox pro ( MacBook Pro (Retina, Mid 2012), 2.6 GHz Intel Core i7,16 GB 1600 MHz DDR3,NVIDIA GeForce GT 650M 1024 MB,Intel HD Graphics 4000 1536 MB ) via the mini display port. This works and doesn't have any problem at all, but when i plugged in my other monitor (24 in Dell), this is when i can reproduce the problem mentioned in this thread.


I tried that kext hack. nadah didn't solve it.


Tried turning on and off that automatic graphics swtiching in the energy saver, nope it didnt work.


I tried putting the main menu bar in the macbook screen and not in the external monitor.


Tried all the resets (Smc, pram etc).

For that dell monitor, I bought a vga to mini display port converter (apple), a dvi to mini display port converter(apple) and also a dvi to hdmi cable just to test and see if any of these will make a difference , but unfortunately, some minutes after i connect the monitor and start browsing in chrome, kernel_task will spiked up and will leave your mac unuseable. Also, i noticed even if you dont use Chrome and the kernel_task/fans won't spike up , when you scroll, there seems to be a lag and the experience is not enjoyable. The solution is always to remove that extra monitor (unplugged the Dell, whether it is connected inthe mini dp or hdmi port and the Asus one remains ) and everything will turn back to normal.


This seems to be a common experience for people who are connecting an extra external display to their macbook nd yet apple is all quiet about it?


Anyone who has figure out this problem?

Same happens with me. It is clearly a matter of an external display. It always happens when an external display is attached. I talked to apple today by they simply ignore that it happens. They suggest that it was a problem with my hardware. But, it is a hardware problem that only happens with Siera!

I have this issue too after update to 10.12.4 dev beta 1. But it happening also without connected external monitor.

Same problem here since the last Sierra update ! My Mac is very slow when I use an external monitor.

Same issue here. It's almost impossible to type this message.

2011 Macbook Air.

Come on Apple. What the ****? Are you diliberately trying to slow my computer so that I feel the need to buy a new slick Mac? Because that's exactly what it feels like you are doing.

FYI, this is not unique to laptops or to sierra - I've been fighting this for several versions.


MacMini mid-2011 running dual monitors, 1 mini-display to VGA, one HDMI to VGA


I also run Chrome, so if the person who thinks that getting rid of some extensions would like to share what extensions they nuked so I can make sure I don't have those, I would appreciate it. I haven't yet been able to tease apart cause and effect between chrome helpers and kernel_task.

Having the same issue. Seems it's the external monitor issue everyone is having. Having 2 monitors plugged in (1 HDMI to thunderbolt and 1 HDMI or 2 HDMI to thunderbolts) causes the issue. Serious problem and we need a fix, anyone downgraded to el capitan? Can't seem to find an easy way to do that.... thanks again Apple...

I thought upgrading to Sierra would fix my problem.

I did, however, had some succes with the "graphics switching" fix. (Settings > Energy Saver > untick Automatic Graphics Switching).

I unplugged the external monitor (Dell), switched off the automatic graphics switching, let kernel_task ease out and then connected the monitor again.

Everything seems okay now..but for how long? I don't know.


It's worth a shot I guess.

I'm also having this problem on my first generation (2012) Retina MacBook Pro running macOS Sierra 10.12.3, with one external monitor connected via HDMI.


I thought at first I was imagining that it was the external display causing a problem, but as soon as I unplug it everything goes back to normal.

The same is happening to me. Sometimes I use my second display for a whole day without a problem and sometimes it happens within minutes. My kernel CPU Usage goes up to 500%. This has been happening since I upgraded to Sierra, then no fix until now.

I'm running a Macbook pro retina 15" late 2013.


Maybe this has something to do with Geforce Drivers? dunno.


Still APPLE HAS TO SAY SOMETHING ABOUT THIS!!!!

The kernel_task consuming the CPU seems to be a feature of MacOS, to manage/lower the temperature of the CPU. The idea is, the kernel_task is blocking the CPU for other processes to lower the power consumption of the CPU and reduce the temperature by this.


See: http://apple.stackexchange.com/questions/193947/cpu-usage-is-too-high-with-yosemite-and-an-external-monitor


It would fit to some occasions when seen:

- Only with External Monitors

- Certain monitor adapters having an effect

- When charging the MacBook

- When system runs virtual machines


This still begs the question, why are so many experiencing high temperatures after an update?


Until then cooling has helped me.