re apply the thermal paste, make sure to use about a pea sized dot in the middle, and let the cooler spread it out
and remember to clean off the cpu+heat spreader, best with 90% alcohol, but 70% works well too
reapplied the thermal paste and cleaned the cpu+cooler, nothing changes...
EDIT: the RPM goes down while the processor temp is not changed. does it mean the cooler becomes more efficient?