Vostro 5481 - fan control

I'm using a Vostro 5481 with Ubuntu for some months now and I realized that the fan goes on pretty late, resulting in lots of CPU throttling. I tried to control the fan speed manually, but the BIOS overrides the value every some milliseconds. Please DELL, publish a BIOS update with an option to disable the BIOS fan control. Or, if you don't want to do this, provide at least two options in the BIOS: "conservative fan control" and "aggressive fan control" so that your users can chose whether they want a silent laptop with average performance or a more noisy laptop with maximum performance. 

Thanks and best
Marc