rb99:
Don't know if this might help to compare how your fan sound to this, as in any significant difference in tone -
https://www.youtube.com/watch?v=k1M4SwRjwDE
Thanks, I'll have to have a listen later when my main computer is on, my tiny Elitebook fan is screaming like it's trying to reach orbit! I am working it hard though, I'm using the internet...
Initial thought is that one sounds like my old fan did, gets louder as fan speed goes up. My current one develops harmonics and extra noises once the fan speed goes over a certain level.