I am experiencing some really strange fan behavior. Every 2-5 minutes there is a brief (yet very irritating) blip in fan speed on my radiator fans. I have custom loop water cooling, and the water in and out temp sensors attached to the radiator. Even with the system idle, the fan speed blips like shown in the attached picture of AI suite. I have tried disabling extreme quiet and running the fans off DC and PWM control (BIOS changes).
The offending fans are 3x EK vardar f3 1850RPM fans all connected to chassis fan 2 header with a fan splitter. I can tell no other fans in my rig do this, as each different fan makes a characteristic noise. This behavior is not due to faulty fans, as when I provide the PWM signal off my oscilloscope's wave gen, the issue does not occur, infact the fan speed does not drift by more than 3RPM. Significantly better than the motherboard blips are a minimum of 50RPM.
When connected to the MBO, the frequency of the blips is increased by using the system, so I'm wondering if the fan speed is affected by not just the selected temp sources.
Although strangely the blips do not occur if the fan curve is perfectly horizontal, only when there is some gradient. The blips are made more frequent/severe by a steeped gradient. This makes me think its some kind of smoothing technology to predict system temps.
Can anyone shed any light on whats going on here. I'm getting pretty close to implementing my own fan controller into the arduino I already have in my case to handle the Aura-->Individually addressable led strip interface. That should mean the fans actually respond properly to water temperature changes, rather than randomly blipping for no reason.