Fans have weird logic and spool behaviour

[nikoelt]

Not sure how everyone is going with their fans but mine are really weird.

I have my laptop aggressively undervolted to -145mv at Core, -100mv iGraphics -75mv Cache and the temperatures are really good on both windows and MacOS. But the fans seem to be broken. I often find myself at 35' (which in Australia is basically ambient temperature) and the fans spooled to 100% concorde afterburner setting. Only to then spool down to 0% which is 1800/1700rpm respectively at 36-40'. It then goes to maximum once again above 40'. Manual controls on iStat Pro sometimes reduces the fans back down, sometimes they do nothing. I yet to find a pattern in this behavior

Bios is set to Silent mode (not that the modes seem to change anything to begin with)

Any suggestions?

[kendreaditya]

I tired to look into the this issue a couple of weeks ago, but since then have moved back to windows. But from what I remember, the SMCDellSensors.kext is what is used to control the fans. The kext only sets the fans at 3 states: low, med, and high. I don't know what dictates which fan setting, so I don't know what causes the weird fan behavior. You could try and install Macs Fan Control as that allows you to directly control your fans.