IMac – the typical CPU utilization of idle iMac

catalinacpuimacmacosperformance

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%).

activity monitor

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)

enter image description here

Best Answer

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.