CPU0: Temperature above threshold CPU0: Running in modulated clock mode

I get the errors above on my new server. The motherboard is Gigabyte with a P4 3GHz LGA775 processor.
I want to disable this warning but the results on Google didn't help.
I'm sitting next to the machine, the fan is working, it's installed correctly. The heatsink is not hot at all and the whole system is not that hot!!
According to the BIOS the temperature of the CPU just after switch-on is 64°C! It goes up to 77°C when I didn't even boot the system. BIOS says the CPU fan is running at 2556rpm.
With lm_sensors I get totally different results. The CPU temperature is 30°C less than in the BIOS. When I try to extract a large archive, I get several warnings (see title) and the temperature (lm_sensors value + 30) rises to 109°C!!
Anyone with similar problems or a solution to switch off these warnings?

 

 

 

 

Top