Hi Nicke,
We sell the ProStar 5694 (P4 desktop CPU) and the 5684 (P4 Mobile) that are the exact same computers as the Sagers. Sager and Prostar are "sister" companies owned by the same families. I use a Prostar 5694 8-10 hours/day everyday and fan noise is not an issue. I believe it does run more than a P4 Mobile but I don't think it is any louder. The 5694 by far is our best seller and customer feedback has been awesome!
Jeff @ Xtremenotebooks.com