So the CPU is used at less than 10%, the temperature is 45°C and the fans spin at 6000 RPM, is that correct?
That is okay at less than 10% CPU use. How warm is your room? It's summer in the northern hemisphere.
Btw, why do you think 45°C is too hot? If the CPU temperature would be 75°C at 10% CPU use despite the fans whirling at 6000 RPM, than you have a problem.