Hello guys!
Anyone out there with high CPU usage issues by kernel_task when you have two monitors connected by Thunderbolt? CPU usage at 1300%. I have to shut down one monitor.
Have tested all the betas and the GM and nothing. In Yosemite works quiet.
My setup;
MacBookPro 15 Retina 2012
2.3 Core i7
16 GB RAM
2 monitors LG
Hi Junqueira,
The following should fix the high kernel_task CPU usage:
Let us know if this fixes it for you...
Max.
Confirmed this help.
I was facing this problem a lot.My CPU usage would reach above 1000 percent and most of it would be by Kernel_task. Whenever we connect second display or use heavy applications ,it requires more gpu/cpu power so our computer heats up more. If the temperature rises too high, Mac Os will run a dummy process "Kernel_task" to reserve cpu usage but keep it idle to reduce load of cpu and protect the computer from burning. As the temperature lowers it will release the resources. The problem in my case was accumulation of dust in the CPU and GPU fan.It had probably sucked it through the side vents. I cleaned it and it works like breeze. I even changed the thermal paste on my CPU and GPU as it had become hard over time and excessive heating. Hope this helps.
Hello @RobbySingh, I suspect it might be the case with me as well. How did you get your CPU and GPU fan cleaned? Did you have to unscrew and open up your Mac Book?
@joeltom21, yes you need to open up your case. But, if you are in US, you can make a Genius Bar appointment at apple store and ask them to open you laptop and clean the fans. They don't charge for this and very safe way to do it as they have appropriate pentalobe screwdriver etc. I had exact same issue with with my MBP, where connecting external monitors would make a 2019 model useless duet o kernel_task cpu usage. When I got the fans cleaned at Apple store, my MacBook was back in game. I am now able to connect two monitors with no issues whatsoever. My MBP runs without any noise where as earlier it used to due to the dust trapped in fans reducing their cooling efficiency.
I was having this problem recently also. Depending on what year your Macbook Pro is... if you have the power (charging) cable plugged into the left side. I would recommend first trying to move the power to the right side of your laptop. This is apparently a known issue with 2019 MBP's especially with the 16 inch model. Also, I found that because i had purchased a magnetic adapter online for my power cable, when i removed it, the high kenel task magically disappeared. Id recommend trying the same!
For whom having external monitors, like I have 2, we also have to make sure external monitors are in good operating temperature too. My symptom was my Mac book was working great in the morning, but began to have this issue in the afternoon. This issue showed up very consistently after entering into summer here. Finally, my solution is to have one fan to cool down my external monitors so that I can continue my work in the afternoon without any problem now. Hope this can help people similar to my.
Do we have any solution for this issue? I’ve been running into the exact same thing with my external monitor connected. Resetting the SMC only helps temporarily but the issue returns after sometime. I have to consistently disconnect my external monitor in order to restore the CPU (kernel_task) spin and then reconnect.
There ought to be a solution out there for this. I’m really hoping Apple support can step in to help with this.
I have the same issue - but only since I upgraded to MacOS Monterrey :( - I need to work with an additional external monitor and especially with the current heat wave it's not possible - I even bought a cooling pad with 5 fans - still the issue persists :(
Same happen to my Macbook Pro 15" 2017 and it seems this issue started after upgrade to MacOS Monterey. It caused the whole laptop freeze and unusable. Can't believe such a premium laptop have this kind of problem! I even formatted my harddisk and reinstalled the Monterey but the issue still persists! Resetting the SMC did not help but disconnecting the monitor immediately see kernel_task dropped. Reconnecting back the monitor will not immediately trigger the problem but after awhile the problem came back.
Hi, I am also am having the same issues and had to disconnect the second monitor. I tried all sort of combination to see if the kernel_task reduces the load but no luck. only when I disconnect the second monitor it seems it goes back to normal. I haven't tried to clean and re paste the CPU and the fans but when I look at the fans it is very clean. not sure if this really an issue. I also run the Macs fan control app to control the fan speed and the temp but I think this is not related to the issue. I also tried the SMC reset and NVRAM etc., but last only few minutes and its back again.... I am very frustrated.. I am running Montery on my mid 2015 MBP... any help really would be appreciated. thanks
Same issue with my 2016 Macbook Pro 15". It was a dual monitor setup, one being a super ultra wide and one regular. No issues whatsoever until all of the sudden it was slower than molasses. Turns out my MacBook was extremely hot (In clamshell mode) even though I'm running fans at full blasts and CPU only reads 50-62 degrees Celsius. Opened the laptop for about minute and it cooled down immediately and kernal usage dropped like a brick on the CPU. My system CPU usage went from 85% to 5% after the laptop cooled down while being open. I read one response on here regarding the charging thunderbolt cable being on the left side, so I've switched to the right to check on how it would handle clamshell mode now. For now it seems fine, though I'm sure that may change here in a couple hours. Respond here and I'll try to report back with an update.
Having the same issue here. I use a dual monitor setup both at home and at work. Funny thing is that it seems only to happen at home. The temperature in both places is around the same. I have in both cases a ultra wide 4K 38" Monitor. At home I connect it through USB-C, the problem seems to disappear shortly after I disconnect the dual screen or reboot the mac. However at work, I don't seem to have the issue, and it is conneced with a display port with an adapter to USB-C
the only way to solve this issue, especially after updating your OS, is by connecting external display/s through HDMI adapter, instade of USB-C.
its working like a charm.
Shame on you Apple.. updating is slowing down your macbook, so you think you need to buy the new one.
Hi Modimoni, thank you for this feedback. I'm in the same trouble, I cannot plug anymore my two screens, it makes my Kernel_Task goes super high, it's super frustrating. The problem I have is my screens doesn't have HDMI plug, they only have USB-C plug. It's LG ULTRAFINE DISPLAY 27". Do you have any suggestions to help ? Many thanks.
I see so many same issue on this topic and it seems there is really no solution as I have tried every single possible things recommended and suggested in the internet..! I think this is a design flaw either software/maybe also hardware by Apple on this models. Apple really should give their position and fix on this..!
Unfortunately same issue here :(
I was having this issue and solved it by adjusting the refresh rate of the external monitor.
In my case it was originally set to 27 hertz. The only other option was 30 hertz. A soon as I switched to 30, the CPU usage dropped. I wouldn't have thought that increasing the refresh rate would ease the CPU usage, but it did.
2019 16" Macbook Pro
I had a same problem for a long time.
I tried everything to fix this issue but no luck.
Finally, I've found a way to fix it.
Just open up the bottom cover and clean the fans and heat-sink.
Like many others in the thread, after opening the back cover, disconnecting the battery and cleaning out the dust with brushes and compressed air, the high cpu usage when using an external monitor seems to have decreased.
Helpful youtube videos:
https://www.youtube.com/watch?v=KyMjUCB-hhU : this was way more difficult than i expected. I felt i should have just gone to an apple store when doing this
https://www.youtube.com/watch?v=tBrKXhkfnAE : this video goes into removing a lot more things than just the battery to apply thermal paste, i didn't do any of that - can be risky to remove and replace a lot of parts. in my case my macbook didn't turn on after i put the back cover on initially and i was freaking out a bit. But it turned out i didn't connect the battery wires properly, i didn't need to lift the 2 small plastic clips for removing the black wire with the S pattern initially, but that lead to the ends not being connected properly when i put it back. the lesson was to follow the video very closely.
Tools i used:
Brushes: https://www.amazon.com/dp/B074LZ649V?psc=1&ref=ppx_yo2ov_dt_b_product_details
Screwdriver: https://www.amazon.com/dp/B07TXFYP5G?psc=1&ref=ppx_yo2ov_dt_b_product_details
FIX to drop kernel_task CPU load when using a 2nd monitor in Monterey:
System Preferences -> Battery -> Power Adapter -> DISABLE/UNCHECK "Automatic graphics switching"
I have tried a lot of things, but this one seems to do the trick while using a 2nd monitor. Besides, you can always re-enable it when you are "on the go", i.e. on battery.
My laptop is under warranty. 2020 i5 16GB. I took it to the shop before reading this thread and found that the error was coming from my external monitors. I was told there was no problem and that the fans were clean, so it's not a solution for me.
With the pre-Monterey version it didn't happen to me. It's a pity. I would say that in version 12.6 they have patched something because I don't get crashes, although it does slow down the computer, with the kernel_task going up to 30-40% and the CPU_speed_limit going down to 50..... It only happens when I make video calls. Without connecting monitors I don't have any problems. I have several colleagues in the company who also have this problem, and another who does not with the same laptop model.
I connect the monitors via HDMI to a hub that connects to the laptop via USB-C. Maybe a different hub would help?
I find it very serious that this is happening. Very bad done by Apple for not providing solutions in my humble opinion.
I have the same problem with my macbook pro 2017, out of support. I've tried almost all recommendations in this forum and others without luck. My external monitor is a Dell and the problems started when I updated to Monterrey. Recently I updated to Ventura 13.0 and the problem remains. Has anyone been able to fix it or a workaround?
Still suffering from this, as I have been for the last two versions of MacOS. Prior to Monterey, no problem, since then, hideous degradation when using my 27" Apple T-Bolt display, which I prefer to do actual work on. I got on chat with an Apple support tech, he thought it should go away with Ventura, but no dice, sadly. It's making my machine unusable, for all purposes, and it's an i9 with 32GB! Doesn't matter how many cycles you can pull, if the OS eats them. I've loved my Mac gear for the last 15 years, but this is shaking my faith.
Has anyone tried connecting to your external display via HDMI only? (I don't have a dongle to try it)
