CPU and system fan revs change?

[Aradur]

I notice from the bios the CPU fan toggles between speeds of 4500 rev and
3518 ...is this natural? - its an Akasa AK785 ball bearing
DC 12V.
Also system fan does the same - 1506 rev to 1454 ? The PSU
is an Antec 480 TruePower.

System is AMD Athlon XP 1.7 on Gigabyte GA-7VTXE

Thanks.

 

[Clint]

Yes, my Antec TruBlue power supply does the same thing. It's done to reduce
noise when the extra cooling isn't needed.. And my MB varies the speed of
the CPU fan, depending on the temperature as well. It's an ASUS
motherboard. You can turn off that feature in the BIOS (for the CPU fan,
not the PSU fan).

Clint

 

[Aradur]

Thanks for that. Ref the Antec TrueBlue...I've recently bought and installed
mine and
wondered if that was the case. Any idea where to find out what's the range
of the fan speeds against temps?. Also do you know if its possible to
manually adjust the fan speed?...I didn't receive much documentation from
Antec.
Thanks.

 

[Aradur]

What order of high and low revs do you get for high and low temps?
As I say my revs seem to vary between 3515 and 4500 for the CPU and 1454 and
1506 for System fan speed.
My CPU temp varies between 50deg C and 69 for no load and after an hour of
full load; and System temps = 41/51C.
Thanks.
-------------

 

[Clint]

Idle (cover off)
CPU temp: 39
CPU fan speed: 2163
MB temp: 30
PSU fan speed: 1548

Load (Prime95 for 30 minutes, cover on)
CPU temp: 58
CPU fan speed: 2576
MB temp: 39
PSU fan speed: 1713

This is with the stock HS and fan. One thing I did was take off the old
thermal pad, lapped the HS, and put it back on with Artic Silver 3 thermal
compound. That dropped the temps by about 10 degrees C at load. At one
point, I was getting CPU temps over 68 degrees.

I only let Prime95 run for about 30 minutes, cause I want to do some other
stuff with my computer today. Hope this helps!

Clint

 

[DaveW]

The fans sound like they are correctly adapting to the thermal load present.