I cannot confirm that the fan noise is different in MacOS compared to Elive, simply for the reason that I no longer have MacOS installed. Sorry. However, what I can say is that Elive seem to manage the fan, and that it knows what the CPU temperature is. So the fan noise is not constant, it varies depending on the CPU temperature (which in turn varies with the CPU load).
So in all likelihood, everything works as it should and the problem is either that I am doing too "heavy" things - like playing a Youtube video - or - more likely - the fan is not doing it's job too well because of dust accumulated inside the casing. Would you have a link to a document or video that explains how to take it apart? I have only been able to locate videos of other Macbook models. Mine is a white early 2009 Macbook (without "Pro") model.
Interesting, but not soo good on a netbook where screen estate is in short supply. I have only 600 pixels on the "y-axis" on this little bugger...
