|Apologies. I don't really know what normal fan RPM speed should be. I just booted up my PC today though and noticed it at 4200 RPM currently. The noise is minimal at the moment, but I'm sure it will climb rapidly.|
The PSU manufacturer is OCZ.
As I finish typing this the cooling fan speed has climbed to about 4500 RPM, and noise is increasing. So I can assume it may be the cooling fan. Might it be a good idea to get a new one?