# reducing noise

## zgredek

Is there any (simple, software) way of reducing the rpms of a CPU fan?

Thanks.

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## SinoTech

I think not, but most new bios's came with an option called "smart temperature fan". There you cn set a desired temperature, and if it is reached the CPU fan gets slowed down.

Another way would be to buy an extern controller letting you control the CPU fan by yourself manually (Didn't really know how that works, but think the fan is conected to the controler, which itself is connected to your MoBo).

Can't think of another way in the moment.

Regards,

Sino

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## zgredek

 *SinoTech wrote:*   

> 
> 
> I think not, but most new bios's came with an option called "smart temperature fan". 
> 
> 

 

Not mine  :Confused:  The fan speeds up/slows down acording to the temperature, but:

 - Its 'reaction' is a *way* to slow

 - The temp. ranges are worgly chosen.

 *SinoTech wrote:*   

> 
> 
> There you can set a desired temperature, and if it is reached the CPU fan gets slowed down.
> 
> 

 

That would be nice!  :Wink: 

 *SinoTech wrote:*   

> 
> 
> Another way would be to buy an extern controller letting you control the CPU fan by yourself manually (Didn't really know how that works, but think the fan is conected to the controler, which itself is connected to your MoBo).
> 
> Can't think of another way in the moment.
> ...

 

The last idea is the one I know about, but I just don't feel like spending money on something that should *just work*...

Thanks for your time.

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## SinoTech

Perhaps you should post a little bit more about your system, so people can give you more suggestions. e.g. notbooks having intel centrino supporting speed stepping and the fan speed gets automatically adjusted (Works nice for me). There're also some more CPU's supporting speed stepping.

Regards,

Sino

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## widan

 *zgredek wrote:*   

> Is there any (simple, software) way of reducing the rpms of a CPU fan?

 

Depending on your motherboard, it can be done with lm_sensors. There is a "fancontrol" script that is able to change fan speed depending on temperature.

 *SinoTech wrote:*   

> Another way would be to buy an extern controller letting you control the CPU fan by yourself manually (Didn't really know how that works, but think the fan is conected to the controler, which itself is connected to your MoBo).

 

Sometimes it is not even connected to the motherboard, just to the PSU and the fans (at least for the multi-channel fan controllers). It's just a variable resistor and a power transistor to drive the fan with reduced voltage.

 *zgredek wrote:*   

> Not mine  The fan speeds up/slows down acording to the temperature, but:
> 
> - Its 'reaction' is a *way* to slow
> 
> - The temp. ranges are worgly chosen.

 

If it's an AMD or Intel stock HSF, then the behaviour is normal. They do have temperature control, but they seem to sense case temperature more than actual heatsink/CPU temperature, so they usually spin like mad (generating a lot of noise in the process) when the case gets warmer.

Also be careful not to reduce fan speed too much... most heatsinks are not designed to work well with low airflow, so the CPU can get hot quite fast.

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## frugal_guy

A common program for controlling fans in Windoze is Speedfan and the folks who provide that program maintain a list of motherboards that support controlling fan speeds through software.  You can try looking up your motherboard here.

If it's there, fancontrol should do what you want.

You might also want to check out Silent PC Review for other suggestions on quieting down your machine.  (they appear to be down at the time I write this  :Sad:  )

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## zgredek

 *Quote:*   

> A common program for controlling fans in Windoze is Speedfan and the folks who provide that program maintain a list of motherboards that support controlling fan speeds through software. You can try looking up your motherboard here. 
> 
> If it's there, fancontrol should do what you want.

 

My mobo is not listed there, does this mean that fancontrol will not work?  :Crying or Very sad: ... 

Hardware: Asrock 775Dual-915GL mobo, the cpu is some weird P4 2.6ghz. 

@widan

 *Quote:*   

> Depending on your motherboard, it can be done with lm_sensors. There is a "fancontrol" script that is able to change fan speed depending on temperature.

 

Cheking fancotrol, and:

```
# fancontrol

Loading configuration from /etc/fancontrol ...

egrep: /etc/fancontrol: No such file or directory

egrep: /etc/fancontrol: No such file or directory

egrep: /etc/fancontrol: No such file or directory

egrep: /etc/fancontrol: No such file or directory

egrep: /etc/fancontrol: No such file or directory

egrep: /etc/fancontrol: No such file or directory

egrep: /etc/fancontrol: No such file or directory

Some mandatory settings missing, please check your config file
```

It seems some it requires some configuration...

 *Quote:*   

> 
> 
> If it's an AMD or Intel stock HSF, then the behaviour is normal. 
> 
> 

 

Yes, it's Intel monster-stock hsf  :Mad: 

 *Quote:*   

> 
> 
> They do have temperature control, but they seem to sense case temperature more than actual heatsink/CPU temperature, so they usually spin like mad (generating a lot of noise in the process) when the case gets warmer. 
> 
> 

 

How good it's a 3500 rpm one, not ~5000rpm (I've seen such!  :Rolling Eyes: ). Another point is that the fan speed does *not* always follow the changes of temperature  :Shocked:  (temp. reported by lm_sensors, I know this may not be accurate). When the temperature is, let's say, 34C (is that much?!) it works at 2700rpms, but sometimes spins up to ~3000, which is makes the box audible from almost everywhere...

 *Quote:*   

> 
> 
> Also be careful not to reduce fan speed too much... most heatsinks are not designed to work well with low airflow, so the CPU can get hot quite fast.
> 
> 

 

If only I *could* do that  :Wink: .

Thank you guys for the tips, really helpful (especially that fancontrol thingy  :Very Happy: ), now I going to make it work (and will probably need assistance), so I'd appreciate any help  :Wink: 

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## widan

 *zgredek wrote:*   

> It seems some it requires some configuration...

 

You need to run "pwmconfig" first to set it up.

 *zgredek wrote:*   

> How good it's a 3500 rpm one, not ~5000rpm (I've seen such! ).

 

There is a lot worse. At one time (several years ago) I had a 60mm Delta Black Label fan (this thing), that was rated at 6800 rpm and 46.5 dB. It was very loud (I think it was called the "Delta screamer"). Most fans made by Delta are very noisy (but also very powerful, that's why they are/were used by overclockers). The worst seems to be the Vantec Tornado fans (the 92mm one is rated at 4800 rpm and 56.4 dB  :Shocked: ).

 *zgredek wrote:*   

> Another point is that the fan speed does *not* always follow the changes of temperature  (temp. reported by lm_sensors, I know this may not be accurate). When the temperature is, let's say, 34C (is that much?!) it works at 2700rpms, but sometimes spins up to ~3000, which is makes the box audible from almost everywhere...

 

The Intel fan senses case temperature more than actual CPU temperature, which is the one lm_sensors measures. So it will not react instantly to CPU temperature changes, but will react when the case air heats up (so with some delay). Also in a case with little airflow, case air temperature can reach 30-40°C quite easily, so the fan will accelerate even with the CPU idle.

From this page from SPCR (I put a link to Internet Archive, as SPCR site is still down for the moment), where they tried to heat up the Intel fan:

 *Quote:*   

> 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.
> ...

 

Even if your particular Intel HSF looks a bit different than the one in the article (there have been a few different models), I guess the fan behavior is quite similar.

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## zgredek

 *widan wrote:*   

>  *zgredek wrote:*   It seems some it requires some configuration... 
> 
> You need to run "pwmconfig" first to set it up.
> 
>  *zgredek wrote:*   How good it's a 3500 rpm one, not ~5000rpm (I've seen such! ). 
> ...

 

I repeated the experiment with a dryer (not 1200W  :Wink: ). It took 10-15 secs for the fan to speed up to the max (only after a few seconds the noise was unacceptable), which came out to be 4500rpms, not 3500  :Shocked:  ...

But, it takes at least a couple of minutes (edit: 10-15 mins  :Shocked: ) to slow the fan down to a normal human-bareable value (which I claim is not more than 3000rpms)... It's still at 4400rpm while I'm writing this...

Something must be wrong here... Mobo temp is 38C, cpu 30C (again - is that much?).

If only I had more (any!) docs/specs regarding the sensors on the board... Yes, I'm desperate. Having to terminate the work just because that <__> thought 37C is too much is annoying.

I'm thinking about some passive cooling (water?  :Rolling Eyes: ), any ideas?

2) pwmconfig does *not* stop the fan(s). It seems nothing can be done right know...

EDIT: I think another serious point is air flow... It seems that whenever I put on the cover (yes, it's off usually) and the CPU is idle the fan gets mad... It's a matter of 10 minutes and I've got 3000 rpms without any reason... Some cases use a kind of an internal tunnel which goes around the hsf making it suck air more easily... Maybe that's the reason? As the computer lies just below a window I though I'd open it a see what happens... The rotation speed dropped down pretty fast...

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## widan

 *zgredek wrote:*   

> I'm thinking about some passive cooling (water? ), any ideas?

 

Seems SPCR is up again: main site and forums. You can look there for some ideas on how to quiet your PC. Yes there are passive watercooling systems, but they are expensive.

 *zgredek wrote:*   

> 2) pwmconfig does *not* stop the fan(s). It seems nothing can be done right know...

 

Some sensor chips can't do PWM regulation, so they won't be able to control the fans.

 *zgredek wrote:*   

> EDIT: I think another serious point is air flow... It seems that whenever I put on the cover (yes, it's off usually) and the CPU is idle the fan gets mad... It's a matter of 10 minutes and I've got 3000 rpms without any reason... Some cases use a kind of an internal tunnel which goes around the hsf making it suck air more easily... Maybe that's the reason? As the computer lies just below a window I though I'd open it a see what happens... The rotation speed dropped down pretty fast...

 

If you look at the previous posts, I said the fan is controlled more by case temperature than CPU temperature in fact. When you close the case, if you don't have some means of taking the hot air out of the case, the fan will speed up quickly, as the inside air will heat up. And yes, the air ducts can help (either by allowing the CPU fan to get cool outside air, or by blowing the hot air from the heatsink out of the case).

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## SirYes

Maybe you should invest in a better cooling system? Like one of Zalman's with a big radiator plus a big and slow fan? Or maybe water cooling? Because if you trim fans too low, you risk the possibility of overheating CPU and/or other components. Obviously replacing a fried CPU+motherboard cost more that a good fan.

BTW, last year I installed a "ThermalTake Schooner Fanless VGA Cooler" to replace a noisy fan on a GeForce card. The result is unbelievable! Now only the two 7200RPM SATA hard drives make the most noise in my home PC.  :Wink: 

BTW.2, IIRC the air tunnel you've mentioned is required for newer P4, exactly because of possible issues with cooling. I have an AMD64 for over a year now and I'm happy! It's cool & quiet until I compile something big, like gcc or KDE for example...

HTH

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## frugal_guy

 *zgredek wrote:*   

> My mobo is not listed there, does this mean that fancontrol will not work? ...
> 
> Hardware: Asrock 775Dual-915GL mobo, the cpu is some weird P4 2.6ghz. 

 

I have a new ASRock 939Dual-SATA2 and it does not allow fan speed control so I suspect you're out of luck here.

It does sound like you have a problem with airflow through your case.  SPCR is the best place to get info on how to fix this.  In addition, you may want to replace case fans or your CPU cooler to get better, and quieter performance.  SPCR has reviews and forums focused on this.

Water cooling is most likely overkill.

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