To Phil who replied to this thread:
I had been monitoring the task manager, but it shows everything
in idle, even when throttling is occurring. I see the CPU at 97-98% for
System Idle Process. Really, cannot find anything software that
is causing this. I am growing suspicious of CPU. It is dual
core. Is there any way to know if CPU temps are abnormally high?
Try downloading HWMonitor from CPUID - System & hardware benchmark, monitoring, reporting and it will report your CPU temperature.
Has it always done this?
It might just be the way the fan controller is designed, it goes very slow to be quiet, then at some point has to ramp to cool the CPU, then goes quiet, then ramps up again. You may have settings in the BIOS that can adjust this.