What is the typical CPU utilization of idle iMac?

I am new to macOS. I recently purchased a 2019 iMac (Retina 4K, 21.5 inch).

               .OMMMMo           OS: macOS 10.15.1 19B88 x86_64 
               OMMM0,            Host: iMac19,2 
     .;loddo:' loolloddol;.      Kernel: 19.0.0 
   cKMMMMMMMMMMNWMMMMMMMMMM0:    Uptime: 18 mins 
 .KMMMMMMMMMMMMMMMMMMMMMMMWd.    Packages: 28 (brew) 
 XMMMMMMMMMMMMMMMMMMMMMMMX.      Shell: bash 3.2.57 
;MMMMMMMMMMMMMMMMMMMMMMMM:       Resolution: 2048x1152 
:MMMMMMMMMMMMMMMMMMMMMMMM:       DE: Aqua 
.MMMMMMMMMMMMMMMMMMMMMMMMX.      WM: Quartz Compositor 
 kMMMMMMMMMMMMMMMMMMMMMMMMWd.    WM Theme: Blue (Dark) 
 .XMMMMMMMMMMMMMMMMMMMMMMMMMMk   Terminal: Apple_Terminal 
  .XMMMMMMMMMMMMMMMMMMMMMMMMK.   Terminal Font: SFMono-Regular 
    kMMMMMMMMMMMMMMMMMMMMMMd     CPU: Intel i3-8100 (4) @ 3.60GHz 
     ;KMMMMMMMWXXWMMMMMMMk.      GPU: Radeon Pro 555X 
       .cooc,.    .,coo:.        Memory: 4009MiB / 8192MiB 

I have noticed that the Acivity Monitor reports the CPU utilization at around 75% -- even when I have all programs closed. About 65% reports as "System" usage, 10% "User", and 25% "Idle".

When I sort the processes by "% CPU" the kernal_task process is using the vast majority of the CPU (~250%).

Is this typical, or is it something to be concerned about?

Edit: added screenshot of Activity Monitor

Edit 2: added screenshot of Activity Monitor and output from ps -al command after booting into Safe Mode (see below)

Solution 1:

A new Mac may use a considerable amount of resources building the database for Spotlight. This may take several hours. but on a new machine, without a lot on it, maybe as low as 30 minutes. If you see a lot of resources being used I'd be concerned. My older iMac is currently just sitting here doing nothing but I have 7 web pages open. Activity monitor says the System is being used 6% of the time, user uses about 20% of the time and its ldle the remaining 74% of the time. Is this consistent with what you are seeing? These values are given on the CPU page to the right of the CPU Load plot.

Even when you are doing nothing, many processes are running in the background as you can tell by the amount of processes listed when you use activity monitor.

Solution 2:

Over time, you should be less than 1-2 % CPU with no processes needing to do work.

That process manages thermal and does other work. What does activity monitor look like, top 20 cpu users? https://support.apple.com/en-us/HT207359

What’s the ambient temperature of the air around the mac?

Also, check the memory, network and disk tabs of activity monitor. If you have IO happening (cloud download, network, spotlight indexing) then even with all apps you normally think of as being quit, the system can run for hours or days if there is work to be done in the background. The good thing, is these background tasks yield if you have front apps to run, so I would walk away for 6 hours and let things run, then check again.

In your case, sort by all CPU time and quit everything you can like Firefox and watch for 15 minutes to see if kernel is quieted. The energy tab also is great for seeing the last day and hour what’s stoking the kernel task fires.