windows 10 - In the "High Performance" power plan, why does the CPU always shows 100% usage?

I've got a Dell Inspiron 11, model 3147, with a Pentium N3540 2.16GHz processor.

I've noticed that when I chose the "high performance" power plan (at Control Panel\All Control Panel Items\Power Options), the CPU will immediately go to 100% usage in task manager, and 125% usage in resource monitor. If I change it to "balanced," it will immediately go back down to below 50%. This happens when I have nothing running except task manager and resource monitor.

When at 100% CPU usage, the processes consuming max CPU don't seem to make any sense. For instance, task manager itself will sometimes show as consuming over 50% CPU.

I have run a scan with Windows Defender and didn't find any malware.

The computer seems responsive despite showing 100% CPU usage.

Is it expected that a Pentium N3450 will run at 100% CPU when in "high performance" mode? Or is there a problem with my laptop?

Below is a screengrab of task manager showing 100% CPU usage.