Cpu fan rpm don't change

[imported_stu3s]

Hi!

I have a problem with my cpu fan. Lately it is fixed at 2500 rpm (with small variations 2450-2550), and cpu temperatures go up until 60ºC when playing something. In idle it's ok -> 35ºC. For a prescott is nothing of the other world, however this as never happened, and jump from 35 to 60 it's not very normal i think!

Before they increased until 50ºC with the fan @4000rpm or more. I do not understand why the fan stoped increasing rotations!

I have a Asus p4p800SE and the stock cooler of intel. It seems like that the fan is manual set for 2500rpm. In the bios the Q-fan technology is enable and ' can't find anything else that is related with the fan speed.

Does anyone know what seems to be the problem?

 

[imported_stu3s]

I think i found the problem.

The stock cooler for prescott runs maximum at 12v and 2500rpm, u can not increase the speed only decrease to 7v@1200rpm and 5v@680rpm.
However the speed on Intel HSF is controlled by a thermistor in the hub of the fan wich measures the ambient temp inside the case.
It's full winter here, so the temp inside my house are pretty low.

"The big gun was brought out: A 1200W hair dryer.
A thermal sensor mounted on the edge of the fan frame recorded the temp, which jumped from ~26°C to nearly 40°C in a matter of 10 seconds of pointing the hot hairdryer at the HS. The fan speed, which had been 2500 RPM at 12V, jumped to ~5800 RPM almost instantly. Taking the dryer away slowed it back down to ~2500 RPM in less than 30 seconds.

A bit more experimentation showed that even at 30°C, the fan speed climbed up to ~3000 RPM. So with the 30~40°C temperatures that prevail around the CPU in a case, the fan would ramp up and probably keep the Prescott P4-2.8 from climbing not much above 60°C. It does become much louder, with a pronounced screaming whine when the RPM goes beyond 3,000."