# AMD Cool & Quiet fan voltages vs CPU/MB temps?

## commonloon

1st, yes I have searched the forums and google'd... while I expected to find this info I didn't.... AMD's site is filled to brim w/ marketing crap!!   :Shocked:  I wondering if anyone else has seen the specifics from AMD as far as a table that lists Cool & Quiet fan voltages out vs CPU/MB temps? Also, if there is a utility like nvclock, but for mobos that would allow on the fly adjustment of voltages out. I have lm_sensors working thus it would be easy for me to read a temp and make adjustments from that... thanks in advance.

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## DocReedSolomon

not sure if i understand you correctly, but actually my motherboard is takeing care about the fanspeeds.

OTOH: "man fancontrol", there is an /etc/init.d/fancontrol startupscript, but i never felt the need to start that one sofar.

additionally: i dont think the fanspeed is regulated by the voltage. but i could be wrong, though..

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## commonloon

Thanks.... I can probably use fancontrol/ pwmconfig to test out what AMD's Cool & Quiet is doing and sort of reverse engineer the table I'm looking for, and it sounds like it will do just what I'm looking for.

Its my understanding that in general most fan controllers "Undervolt" 12V fans (6-7 volts minimum to get spinning) in order to produce lower (quieter) rpms. I have a fan controller in this box, but my CPU/MB is running so cool (~25C) most of the time I think I could stand to shut off a fan or two when its at idle. I wondering if AMD's internal stuff would do a better job for me w/o any work and/or find something to give me more control over it...

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## DocReedSolomon

well, it is your risk. you have to know what you are doing..

shutting off the CPU Fan - even for a short time - might burn your CPU to hell and gone.

i would not take that risk!

and - as i already mentioned, my mobo and AMDs Cool&Quite does this all by itself for me.

you have been warned   :Exclamation: 

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## commonloon

Yes, "Don't try this at home," thanks...

I'm not exactly a novice and the box has 3 nexus 120 fans and a thermalright 120 heatsink on the CPU. 2 fans are acting on the heatsink in a push-pull configuration. I could probably remove 1 fan completely and the box would be fine, but run slightly hot under load. My preference is to simply have one auto-stop under low load/idle... I actually recently had a 1U dual Xeon server go down because 4 of its 7 fans had died (old server), and it heated up so fast that it wasn't until I had out (was racked) that I figured out why.

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## commonloon

So, here is hopefully a little slightly interesting follow up... I just tried 3 scenarios (note just messing with the primary CPU fan, load is at my baseline w/ qmail and apache and X running but no intensive stuff):

1. AMD's fan control:

```

fermat ~ # sensors

w83697hf-isa-0290

Adapter: ISA adapter

VCore:     +1.50 V  (min =  +1.71 V, max =  +1.89 V)

+3.3V:     +3.25 V  (min =  +3.14 V, max =  +3.47 V)

+5V:       +5.05 V  (min =  +4.76 V, max =  +5.24 V)

+12V:     +11.25 V  (min = +10.82 V, max = +13.19 V)

V5SB:      +5.54 V  (min =  +4.76 V, max =  +5.24 V)

VBat:      +3.07 V  (min =  +2.40 V, max =  +3.60 V)

MB Fan:      0 RPM  (min = 1328 RPM, div = 4)

CPU Fan:  1068 RPM  (min = 5273 RPM, div = 8)

MB temp:     +26 C  (high =   +45 C, hyst =   +40 C)   sensor = thermistor

CPU temp:  +26.5 C  (high =   +52 C, hyst =   +47 C)   sensor = thermistor

```

2. fancontrol/pwmconfig:

```

fermat ~ # sensors

w83697hf-isa-0290

Adapter: ISA adapter

VCore:     +1.50 V  (min =  +1.71 V, max =  +1.89 V)

+3.3V:     +3.25 V  (min =  +3.14 V, max =  +3.47 V)

+5V:       +5.05 V  (min =  +4.76 V, max =  +5.24 V)

+12V:     +11.31 V  (min = +10.82 V, max = +13.19 V)

V5SB:      +5.54 V  (min =  +4.76 V, max =  +5.24 V)

VBat:      +3.07 V  (min =  +2.40 V, max =  +3.60 V)

MB Fan:      0 RPM  (min = 1328 RPM, div = 4)

CPU Fan:   694 RPM  (min = 5273 RPM, div = 8)

MB temp:     +26 C  (high =   +45 C, hyst =   +40 C)   sensor = thermistor

CPU temp:  +26.5 C  (high =   +52 C, hyst =   +47 C)   sensor = thermistor

```

3. SilverStone external fan controller (CPU fan @9V = 940 rpm):

```

fermat ~ # sensors

w83697hf-isa-0290

Adapter: ISA adapter

VCore:     +1.50 V  (min =  +1.71 V, max =  +1.89 V)

+3.3V:     +3.25 V  (min =  +3.14 V, max =  +3.47 V)

+5V:       +5.05 V  (min =  +4.76 V, max =  +5.24 V)

+12V:     +11.31 V  (min = +10.82 V, max = +13.19 V)

V5SB:      +5.54 V  (min =  +4.76 V, max =  +5.24 V)

VBat:      +3.07 V  (min =  +2.40 V, max =  +3.60 V)

MB Fan:      0 RPM  (min = 1328 RPM, div = 4)

CPU Fan:   0 RPM  (min = 5273 RPM, div = 8)

MB temp:     +26 C  (high =   +45 C, hyst =   +40 C)   sensor = thermistor

CPU temp:  +26.5 C  (high =   +52 C, hyst =   +47 C)   sensor = thermistor

```

It seems that if I use fancontroller that I can eek out a little less noise at idle. Definitely split hairs. I'm not sure also if I want to completely rely on software based control.

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## DocReedSolomon

 *commonloon wrote:*   

> 
> 
> It seems that if I use fancontroller that I can eek out a little less noise at idle. Definitely split hairs. I'm not sure also if I want to completely rely on software based control.

 

thats why i use cool&quiet in my BIOS. does everything for me.

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## bLUEbYTE84

Turn on cool n quiet in your BIOS (if there's a setting), have powernow support in kernel and activate the userspace governor (follow the Gentoo Powernow HOWTO) then try this program for voltage adjustments:

http://www.tuxamito.com.es/cpupw/index.php

About me:

I use the powersave governor which always keep the CPU in lowest voltage & freq. and run it fanless. My CPU is a Sempron64 3000+

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## DocReedSolomon

april 1st comeing early?

 *bLUEbYTE84 wrote:*   

> 
> 
> I use the powersave governor which always keep the CPU in lowest voltage & freq. and run it fanless. My CPU is a Sempron64 3000+

 

why do you run a 3000sempron if you *always* run it @ <= 1Ghz?

of course everyone using gentoo likes to give full power to the CPU if the machine is compiling, or does whatever CPU intensive jobs.

without a fan, @what MhZ is your CPU running? just wondering..

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## bLUEbYTE84

I don't do compiling. This machine has a fixed role.

 *DocReedSolomon wrote:*   

> april 1st comeing early?

 

I don't think so.

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## DocReedSolomon

 *bLUEbYTE84 wrote:*   

> I don't do compiling. This machine has a fixed role.
> 
> 

 

you *have* to compile if packages are outdated and you might run into vulnerabilitys.

but OTOH it does not answer my question why you would need a 3000+ if you slow it doen to <=1Ghz.

so, what MhZ are you actually running the machine without cooling the CPU at all? just out of curiousity..

this could work with a 5xxMhZ P2, but i have not seen any sempron yet without cooling the CPU, thats why i am asking.

and lets not forget there is probably a minimum voltage to make this CPU work at all.

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## energyman76b

Hi,

cool'n'quiet has nothing to do with the fan speeds.

The speed of the fan is detemind by the temp of the cpu/cooler. The mainboard monitors the cpu temp and adjusts the fan, or the fan monitors the cooler temp and adjusts itself. The CPU has nothing to do with that.

That said. My extrem cheap motherboard has a nice built-in overheating protection - so when the fan ever stops working and the CPU becomes to hot, the mobo will just shut down (called u-cop). It does not influence the fan speed in any way, which is ok, because my cheapo arctic cooling fan has its own temp control.

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## bLUEbYTE84

 *DocReedSolomon wrote:*   

>  *bLUEbYTE84 wrote:*   I don't do compiling. This machine has a fixed role.
> 
>  
> 
> you *have* to compile if packages are outdated and you might run into vulnerabilitys.
> ...

 

Dude, I'm using Slackware. Why you insist on making assumptions?   :Rolling Eyes: 

This CPU is a Palermo Sempron 64 E3 Stepping. Has C'n Q support and also supports sse3 ins. sets. I'm telling just for the record.

It's default voltage is 1.4 V, default freq:1.8 ghz

Has two P-states, one is the above and the other (low) one is:

1.1V 1.0 ghz.

Too bad I can't set it below 1.1 V (it seems to be prevented by hardware, doesn't let it go below this value)

It's around 50 degrees celcius.

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## DocReedSolomon

 *energyman76b wrote:*   

> Hi,
> 
> cool'n'quiet has nothing to do with the fan speeds.
> 
> 

 

well, it actually has because:

 *energyman76b wrote:*   

> 
> 
> The speed of the fan is detemind by the temp of the cpu/cooler. The mainboard monitors the cpu temp and adjusts the fan, or the fan monitors the cooler temp and adjusts itself.
> 
> 

 

right, but the mainboard BIOS has to support this, otherwise this will not work. and if the mainboard supports this, you do not need aditional programs. thats what the oposter understood already meanwhile, i assume. all he gained was a little less RPMs by doing this manually.

 *energyman76b wrote:*   

> 
> 
>  The CPU has nothing to do with that.
> 
> 

 

correct. the CPUs voltage is handled by powernowd (if installed).

 *energyman76b wrote:*   

> 
> 
> That said. My extrem cheap motherboard has a nice built-in overheating protection - so when the fan ever stops working and the CPU becomes to hot, the mobo will just shut down (called u-cop). It does not influence the fan speed in any way, which is ok, because my cheapo arctic cooling fan has its own temp control.

 

OK; this is getting offtopic, though:

i had to switch this feature OFF, because the CPU FAN WARNING by the BIOS always gets active if i turn my machine ON. it takes a while, to get the CPU FAN SPEED @900RPM, and 900RPM is the minimum i am able to set in my BIOS.

this is an AMD BOXED CPU.

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## DocReedSolomon

 *bLUEbYTE84 wrote:*   

> 
> 
> Dude, I'm using Slackware. Why you insist on making assumptions?  
> 
> 

 

because we are on the gentoo forums?

we do not expect you are running Mac-OSX, Win Vista, Slackware, LFS or whatnot, right?

i dont think commonloon asked for this.

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## commonloon

In my continued obsession to get my workstation running very quiet and very stable (i.e. cool)... I found this good link on temps:

http://www.heatsink-guide.com/content.php?content=maxtemp.shtml

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