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BigSur high CPU use. WindowServer and Kernel_task always on top.

Three times. I downgraded three times from BigSur to Catalina and it seems that I am going to do it again.

I expected the latest BigSur 11.3 will solve the high CPU consumption, but it is not.


To give it the latest opportunity I request for help to this forum to try anything to get BigSur running normal.

Mi MacBookPro13,1 (2016, i7 2,4Ghz, 16GB ram) runs slow and it get completely unusable when I need to do normal task (mainly with Microsoft suite: PowerPoint, Teams, OneDrive and Outlook).


Here a screenshot of the same computer running Catalina from a clean boot:


Look at System processes: 0,95% CPU. None app running, just the activity monitor.


Now, the same computer running BigSur, same clean boot, just after a fresh installation from a bootable USB of BigSur 11.3.... but....


WindowServer always on top with 66% of CPU going to 80%, even more sometimes.

And Kernel_task always there too with 5% of CPU going to 15%, 30%.


I know this is not normal as I have a MacMini 2015 (i7, 3,0Ghz, 16GB) running BigSur without problems using less than a 1% from a fresh boot. It seems the operating system is not the problem (or it is a specific problem with this hardware).


Is there any way to fix this? Or BigSur consumes so much CPU in this kind of MBP? and I am forced to go back to Catalina again?.


The computer is clean and BigSur is just installed, so any idea is welcome and I can test anything without risks. Not high expectations as I have read tons of post on internet and none of them worked by now.


Thanks a lot in advanced!!.

Regards







Posted on May 2, 2021 11:21 AM

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8 replies

May 2, 2021 12:40 PM in response to Old Toad

Thanks a lot Old Toad!!,


I run EtreCheck and it gave me one major issue and two minor.


The major one is related to my corporate Anti.Virus (Microsoft ATP Defender) which perhaps is not compatible. I will check the Microsoft support website of this product to see if there are other users with the same issue.

I do not know the change in the BigSur OS from Catalina, as this software worked perfect in Catalina.


Minor issues are related to two things:

  • Other corporate software, Cisco Anyconnect, which is a VPN client that we need to connect to the corporate network
  • An issue with Time Machine, as I have an old time capsule to do my backups, but I have so many that I wanted to delete some of them. As it is impossible in the user interface of time machine today, I needed to use tmutil from the terminal and it seems same hard links got wrong.


I am going to uninstall both apps and I will test it again to see off those were the root problem.

As this is the corporate software I have to have installed, I guess I will back to Catalina again :).



Thanks a lot!!!




May 2, 2021 12:08 PM in response to Straycat123

Welcome, Straycat123, to Apple Support Communities!


Since I don’t see any other processes using much CPU, besides the Window Server (which handles Graphical User Interface [GUI] tasks for your Apps), it’s hard to see why your «MacBookPro13,1 (2016, i7 2,4Ghz, 16GB ram) runs slow»., or even why the Window Server is using «66% of CPU going to 80%, even more sometimes.»


The typical issue with slow response, high CPU usage for Big Sur, relative to Catalina, is old, incompatible software: including background tasks for such software and driver software for add-on hardware.


High «kernel_task» CPU usage is due to system/kernel extensions as well as hardware driver software.


Are you running any “Anti-Virus”, “Cleaner”, “Optimizer”, etc. software? Such could easily do such!


By the way, the CPU % is not showing the percentage total CPU usage, relative to total possible, but is only showing the percentage of a single CPU core, equivalent: so, for a four core machine, it can go up to 400%, for multithreaded workloads.


Have you checked your software (and add-on hardware) for compatibility with Big Sur?


One should always perform such a check before upgrading (not a mere update) to a new Operating System (OS).

May 2, 2021 1:59 PM in response to Straycat123

Here's some food for thought: there is no reason to ever install or run any 3rd party "cleaning", "optimizing", "speed-up", anti-virus or security apps on your Mac.  This user tip describes what you need to know and do in order to protect your Mac: Effective defenses against malware and other threats - Apple Community.  


There are no known viruses, i.e. self propagating, for Macs.  There are, however, adware and malware which require the user to install although unwittingly most of the time thru sneaky links, etc.   


Anti Virus developers try to group all types as viruses into their ad campaigns of fear.  They do a poor job of the detecting and isolating the adware and malware.  Since there are no viruses these apps use up a lot of system resources searching for what is non-existent and adversely affect system and app performance.


There is one app, Malwarebytes, which was developed by a long time contributor to these forums and a highly respected member of the computer security community, that is desshoigned solely to seek out adware and known malware and remove it.  The free version is more than adequate for most users.  


With that in mind you might talk with your IT personnel at work and see if you can forgo the Microsoft junk.


As for the VPN as long as you're using it to connect directly to your company's servers it is a good thing. Public VPNs are worthless from a privacy standpoint: Public VPN's are anything but private.  


If you can uninstall the Microsoft Defender temporarily to test its affect on your Macs performance you'll have additional ammo for the talk with the IT people. If they insist on a anti-virus app see if they will let you use ClamX. It appears to be the most benign A/V app in regards to Mac's performance.


Another tact you can take is to boot into Safe Mode according to Start up your Mac in safe mode - Apple Support and see if the problem persists. Reboot normally and check again.


NOTE: Safe Mode boot can take up to 10 minutes as it's doing the following; 

• Verifies your startup disk and attempts to repair directory issues, if needed

• Loads only required kernel extensions (prevents 3rd party kernel/extensions from loading)

• Prevents Startup Items and Login Items from opening automatically

• Disables user-installed fonts 

• Deletes font caches, kernel cache, and other system cache files


Again, more info for the IT personnel. Good luck.

May 3, 2021 10:45 AM in response to Straycat123

There is no reason to ever install or run any 3rd party "cleaning", "optimizing", "speed-up", anti-virus, VPN or security apps on your Mac.  This user tip describes what you need to know and do in order to protect your Mac: Effective defenses against malware and other threats - Apple Community.  


There are no known viruses, i.e. self propagating, for Macs.  There are, however, adware and malware which require the user to install although unwittingly most of the time thru sneaky links, etc.   


Anti Virus developers try to group all types as viruses into their ad campaigns of fear.  They do a poor job of the detecting and isolating the adware and malware.  Since there are no viruses these apps use up a lot of system resources searching for what is non-existent and adversely affect system and app performance.


There is one app, Malwarebytes, which was developed by a long time contributor to these forums and a highly respected member of the computer security community, that is desshoigned solely to seek out adware and known malware and remove it.  The free version is more than adequate for most users.  


Unless you're using a true VPN tunnel, such as between you and your employer's or bank's servers, they are useless from a privacy standpoint: Public VPN's are anything but private.  



May 2, 2021 12:45 PM in response to Halliday

Hello Halliday,


Thanks a lot for your answer. Probably you are right!!.

Running Etrecheck I discovered that I am having issues with two apps:

  • Microsoft ATP Defender: which is my corporate anti virus (as you suggested). Sadly I can not quit it, so, I am going to visit Microsoft support website to see if there are other users with the same issue or a new version compatible.
  • Cisco AnyConnect: our corporate VPN Client. I can not avoid it, so, I will do the same.


I will contact with my corporate IT service to request a BigSur compatible version, if they exists. As I work with Mac as my own device, the company allows it but they usually are not able to give us the same support than if I used the corporate PC under windows (I can not do this, :):):), no way)


Thanks a lot for your quick, and accurate, clue.

Regards

May 2, 2021 11:54 AM in response to Straycat123

Download and run Etrecheck. Etrecheck is a diagnostic tool that was developed by one of the most respected users here in the ASC and recommended by Apple Support  to provide a snapshot of the system and help identify the more obvious culprits that can adversely affect a Mac's performance.


IMPORTANT:

Before running Etrecheck assign Full Disk Access to Etrecheck in the Etrecheck's Privacy preference pane so that it can get additional information from the Console and log files for the report:


Also click and read the About info to further permit full disk access.



Copy the report



and use the Additional Text button to include the report in your reply.



Then we can examine the report and see if we can determine what might be causing the problem.


May 3, 2021 1:15 AM in response to Straycat123

Hi all,

Just to help other users with the same problem.


I reinstalled BigSur from scratch and I can confirm that the high CPU consumption was due to Microsoft ATP Defender (my anti-virus) and Cisco AnyConnect (my VPN client).

Both are not BigSur compatible or there is something to do from my corporate IT department to properly set additional configuration profiles needed.

I found the info here:

https://docs.microsoft.com/en-us/microsoft-365/security/defender-endpoint/mac-whatsnew?view=o365-worldwide


In order to confirm the stability of BigSur in a MBP 2016 i7 2,4Ghz, 16GB ram, I add a screenshot of the system monitor with the same behavior then I had with Catalina, less than 1% of CPU and no WindowServer or Kernel_task running on top.



I ran Etrecheck too getting no issues major or minor.


Thanks a lot to Old Toad and Halliday for your great support with this!!.

Regards.

BigSur high CPU use. WindowServer and Kernel_task always on top.

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