I built my girlfriend a machine a few months back and have never been able to determine the cause of her CPU fan surging. I have downloaded an array of monitoring services such as CPU Core Temp, Fan Speed, etc, and isolated it to the CPU case fan. I applied a hefty amount of Arctic Silver upon build so I do not feel this is an issue and have 120 MM fans on the NZXT Whisper case.
The problem seems to occur most frequently when doing routine tasks such as when the screensaver triggers or when working on Word documents while streaming music. The temps will rise to around 40C and then drop to about 30C once the fan "Revs up", then the process repeats about 5 seconds later. It has become an extreme annoyance and I am lost pondering the solution/causation.
Has anyone else encountered similar issues or have any suggestions? I have a Gigabyte 990FXA-UD3 mb, and AMD FX6200 CPU running stock cooler.