Here is plugin for automatic temperature control, if somebody want try it. Tried on dm800se and vu ultimo. For vu ultimo use "Control with" as "pwm" only, "vlt" has no effect for VU.
It is no fast regulation, will be patient... you can set approximately Voltage, PWM too for less time
And I do not know, how much it will be good for fans, when will be changed rpm time to time.
"Threshold pwm/vlt" ... when is changed VLT (PWN is 0 or 255), set this value as starting PWN again (for less jumps in rpm)
And set "Check time" to 1s, I forgot default on 30s.