Variable fan max speed? Why?

[tinynja98]

Hello there!

I have been using the software SpeedFan for quite a while now and i noticed that the maximum speed of the stock Intel CPU fan varies a lot from boot to boot (not sure if we can say that ). What i mean is if i boot my pc right now and set the speed of the CPU fan to 100%, let's say it turn at around 2400rpm. If i shutdown my pc then reboot it and do the same thing, the cpu fan might turn at 2800rpm max speed. Right now, as i am typing this post, the max speed is around 2000rpm, but i have already seen it go at 3000rpm 2 months ago. However, the maximum rpm of the cpu fan never changes in the same boot, even after putting the computer into hibernate mode.

So my question is what do you think can be causing this variability?

PC Specs:
i7 920 @ 3.2GHz with Stock Intel Cooler
Intel DX58SO Motherboard
Coolermaster V650 PSU

 

[Lutfij]

Are you sure your BIOS for the motherboard are up to date? Have you made sure your CPU temps are in order and not going to alarming areas when your fan speeds seem to be low? If not then the C states must be at play and perhaps a small error on Speedfan's part as the same issue with rpm's was found when I used AiProbe II alongside CPU-Z and if I cranked up my pump speed my motherboard would report an fan/rpm failure on the pump fan header.Can you please pass on your full systems specs?

One other thing to note is to see what your stock cooler speeds are within BIOS, nothing would beat that monitoring tool!