While doing some stress tests i monitored the temperature of my HP N40L. The N40L mainboard has 3 sensors: CPU, Nothbridge and Ambient. The room where the servers are located has a temperature of 20°C. Surprisingly the fan speed did not change, even at full load.
Here are my results:
North Bridge: 37°C
Moderate Load (Both CPUs at 50% and some harddrive activity):
North Bridge: 38°C
North Bridge: 39°C