I built a ST61G4 for a client and they have been complaining about the noise, so last week I replaced the 80mm fan with a nexus and cut out the restrictive grill in the back. It was a big improvement but then the Northbridge fan was the loudest component. I had a zalman fan controller and reduced the speed on the 40 mm fan as much as I could until the fan started making a pronounced clicking. I then unplugged the 40mm fan altogether and the machine is really quiet. The Northbridge is recording between 47 and 52 deg C. originally the temp was ~37 degC My next step is to remove the fan from the original heatsink and check the temps. My CPU (p4 2.8c) is running nice and cool at 32C. I would like to put a larger heatsink in it but I don't want to glue it on. I understand that gluing is the only way to put a Zalman on. Does anyone have any ideas on a passive heatsink that uses the hooks at the corners. Also does anyone have any experience with the temp. of the NB and at what temp I should be getting worried. Thanks Doug