CPU fan sometimes starts at 100% when booting and never slows down

14 Apr 2015

Specs:
MB: Sapphire PC-AM3RS890G (AMD)
CPU: AMD Phenom II X4 965
CPU fan: well, I don't remember. Not the stock one though.
Cool'n'Quiet is enabled.

The CPU fan sometimes starts at 100% (quite some noise) when booting the PC and never slows down, even if I wait minutes/hours. However, if I reboot it works again.
I know that it's normal that when booting the fan is at 100%, but only for the first seconds.

I don't want to update the BIOS since it looks like it's risky.

So I thought about chipset drivers. I'm downloading Sapphire chipset drivers for my MB. Do you think this could solve the problem?
Is there any risk in installing chipset drivers? AMD is known for driver issues.

carwiz · 14 Apr 2015

After installing Windows and getting a stable system, the motherboard drivers should have been the first thing to go on your PC. I'm not familiar with AMD so the drivers might help. Otherwise, it's probably a setting in the BIOS. I don't see a BIOS update for your board.

whs · 14 Apr 2015

I have one desktop which does that too. After booting I put it into sleep and then resume from sleep. That stops it.

16 Apr 2015

whs said:

I have one desktop which does that too. After booting I put it into sleep and then resume from sleep. That stops it.

Well, there must be a definitive solution too, though.

carwiz said:

it's probably a setting in the BIOS.

For example?

carwiz · 16 Apr 2015

For example; Active or Passive monitoring, fan speed settings, etc. Maybe you have the wrong fan(s). "PC/Desktop" in your specs isn't much detail to go on so you'll have to check your BIOS and/or Motherboard manual.

17 Apr 2015

Specs are in OP.

30 Apr 2015

Installing the chipset drivers didn't help...

carwiz · 30 Apr 2015

Did you load all the drivers from your CD/DVD supplied with the motherboard? Apparently, your motherboard needs the "PC-Health" utility/driver installed to control the fan speed as defined in the BIOS. The BIOS settings for FAN1/CPU FAN are entered in a speed step table corresponding to CPU temperatures. But it says this only works if the monitor utility is installed.

Also make sure you are using the correct fan(s) and the correct fan headers on the MB. Do NOT parallel fans using Y-connectors with this motherboard. Each header will support only 340mA.

carwiz · 30 Apr 2015

Forgot to mention:

You DO need to review the fan speed settings in the BIOS. (As mentioned earlier)

This setup has temperature steps in degrees Celsius. For each temperature step, there's a fan speed given as a percent of maximum fan speed (Fan dependent). So if you use 2000rpm fans and you set the percent to 50, the fan runs at 1000rpm starting at the temperature entered. I saw no response options in the MB documentation so I would not run the fan less than 50% (or about 1000rpm) for any temperature.

01 May 2015

Thanks for trying to help.
I don't understand much of what you're talking about, however the fan speed is working fine as it is, except the occasional problem in OP; the fact that the problem is irregular/occasional, made me conclude recently that there's just some hardware problem with the mobo; in fact it doesn't really make sense to edit anything at all in the BIOS or anywhere else. Things just have to work, advanced options are just for advanced needs. And in fact, things works, mostly.
The idea of an hardware problem / faulty MB is strengthened by the fact that I didn't have this problem before and that I recently got another problem that may be related to the mobo: I've extended my RAM and only 8 on 11 GB is usable, the other "are hardware reserved". There are a lot of internet pages/forums where this problem does happen and a lot of non-working solutions are given; I tried them all and the only one that makes sense and that I've not tried yet is to check for bent pins on the cpu.
I think these two problems I have could simply be related to this, since in the past I've manually mounted a new fan and probably I did something wrong.
As soon as I buy a new thermal paste I'll open the case and I'll re-install the fan and check the CPU pins.
Hopefully this will solve both the problems I have (the fan and the RAM ones).