Reliable CPU fan speed controller?
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From: JD on 25 Oct 2009 19:35 JD wrote: > Paul wrote: >> JD wrote: >>> Paul wrote: >>>> JD wrote: >>>>> I have a CPU fan that runs all the time at around 4,100 rpm. >>>>> This is completely unnecessary when the weather is cool. I believe >>>>> a speed >>>>> of about 3,000 should be ok at present. >>>>> >>>>> Is there any such program around? I know about SpeedFan but I think >>>>> it's a primitive piece of work. The CPU needs a delicate touch. >>>>> >>>>> I did a search and found >>>>> http://wareseeker.com/free-cpu-fan-speed-control-software/ >>>>> However it's hard to tell whether they are discussing the cpu speed >>>>> or the fan speed. >>>>> Anyone have experience of these? >>>>> >>>>> TIA >>>> >>>> Have you looked at your BIOS functions ? Maybe there is >>>> an option in there to control the fan. >>>> >>>> Paul >>> >>> Great suggestion Paul. >>> >>> I looked in the BIOS and found 2 options for the fan >>> Fan Control - [Enabled} >>> Lowest Fan Speed - [Slow] >>> >>> The first one had no speed control as far as I could see and was the >>> existing >>> setting since the motherboard was installed >>> I set it to the 2nd one and rebooted. >>> It was exactly the same as before - whizzing along at 4,100 + or - a >>> few hundred. >>> >>> I did have this fan plugged into the right socket - it is right >>> beside the CPU. >>> I looked in Control Panel - Add-remove hardware and it was no help. >>> Likewise in the Control Panel itself. >>> Do you know of any other possible location for a fan speed controller? >>> >>> TIA >> >> Maybe the next test, is to try Speedfan. If Speedfan cannot get any >> response from the fan, then it could mean there simply isn't >> a hardware feature there to control the speed with. (It could mean, >> for example, that you've mixed incompatible components together. >> Or that the motherboard makers are cheapskates.) >> >> The rest of this is some background. Mixing a three pin fan with >> a four pin fan header, may deprive you of a control method. And >> that is an example of how you can accidentally be stuck with >> a screaming fan. >> >> ******* >> >> The CPU fan header has a couple features to control fan speed. >> Back in the "three pin header" days, voltage control was used. >> The fan normally runs from 12V. But the motherboard could control >> the voltage, and deliver a variable voltage between 7V and 12V. >> This would take a PWM output from the controller, and require a >> MOSFET or transistor near the fan header, plus a capacitor, >> to convert the pulse width modulated control signal, into >> a voltage. It costs the motherboard maker some money to do that. >> >> X <--- RPM (from fan to motherboard, for monitoring) >> X ---> 7 to 12V to power fan >> X --- Ground >> >> If you're using Speedfan, Speedfan may find the registers that >> control the PWM output. The register can be programmed, and >> the hardware chip is then outputting a PWM signal. But if the >> motherboard maker wants to save money, they don't bother to >> install the interface circuit (the MOSFET and capacitor). Speedfan >> cannot tell those components are missing. So one of the checks >> I make, when someone has this problem, is to look at a picture >> of the motherboard, and see if the appropriate looking components >> are installed nearby. >> >> (Some general rules of thumb. Prebuilt systems from HP/Dell/Gateway >> are the ones most likely to have fan control per header. Which >> means they have the most fan control of all. On an Asus motherboard, >> the cheapest boards have no fan control. A board with QFan has the >> CPU fan controlled. A higher end board with QFan2, has two headers >> under control, one via CPU temp, one via chassis temp. So that should >> give some idea what to expect in terms of working channels. With the >> four pin fan header generation, you're much more likely to have a >> CPU fan control, so the situation should be getting slightly better >> as time passes.) >> >> ******* >> >> The second control method, is of more recent design. Both >> Intel and AMD now use four pin fan headers for CPU. The fourth pin >> is (what a surprise) PWM. What is happening in this case, >> is the responsibility for the MOSFET and capacitor, is now >> up to the fan manufacturer, as they're inside the fan. The motherboard >> has a fan controller interface on it somewhere (I can't say >> right off hand, where this one is located now). The logic >> signal output, running at perhaps 25KHz, is delivered on the >> fourth wire of the fan. The fan runs at full 12V all the time. >> The conversion circuit inside the fan hub, uses the pulse >> width of the PWM signal, to control the voltage delivered >> to the fan. That means the fan can run at 7V, using a >> circuit inside the fan hub to make the 7V from the supplied >> 12V. >> >> X ---> PWM (from motherboard to fan, 25KHz, indicates speed desired) >> X <--- RPM (from fan to motherboard, for monitoring) >> X ---> 12V DC (power from motherboard to fan) >> X --- Ground >> >> So as a consequence of having that fourth wire and control >> method, Intel recommends not attempting to reduce the 12V >> fed to such a fan. That recommendation, is so the MOSFET >> has sufficient signal applied, so it will be biased properly. >> >> Now, imagine what would happen, if you purchased an aftermarket >> heatsink/fan combo, with a three pin connector, and connected >> it to a four pin header. No PWM signal. No variable 12V. >> And hence, no control method. Again, programs like Speedfan >> will feel they're "dialing the knob", but nothing happens. >> >> ******* >> >> There is one other feature, which was used in the past with >> Intel fans. They had a thermistor in the fan hub. If the >> computer case air temperature rises, the fan is set to >> spin faster, based on the measurements by the thermistor. >> That feature does not lend itself to control by the user. >> Its purpose is to compensate for the worse cooling situation >> caused by hot case air. So if the computer has poor ventilation, >> the CPU fan may scream a lot more than it would in a cooler >> running case. Any other control method applied, multiplies >> its effect, by the effect provided by the thermistor. So if >> the computer case was very cool, the fan may hardly be >> turning at all. >> >> Speed = Voltage_controlled_speed * thermistor_set_speed >> >> Anyway, my next steps would be some Speedfan testing, and >> some visual inspection. Like, checking whether there is a >> three pin fan connected to a four pin header. On an older >> motherboard, whether the appropriate components are next >> to the three pin headers, and so on. As far as I know, there >> isn't a programmatic way of determining whether the controls >> are actually hooked up and working. A program could certainly >> observe the RPMs, and notice that nothing is happening, but >> I'm not aware of any program bothering to carry out such an >> analysis for the user. >> >> During the transition from three pin to four pin CPU fan >> header, Asus made some motherboards with dual control >> methods. The four pin header could be controlled as if >> it was a three pin header. There was a BIOS setting, >> that determined whether voltage control or PWM >> control was used. And that means, on a small range of >> motherboards, there is yet another BIOS setting to check >> for. That practice was soon discontinued, in favor of >> pure PWM control for four pin fan headers. Meaning >> that the providers of aftermarket coolers, should >> provide proper four pin fans, if they expected >> satisfied customers. When you buy a retail CPU now, >> from either Intel or AMD, you should expect to >> find a four pin fan packaged with the retail CPU. >> >> Paul > > Thanks again Paul. I haven't read the above yet. Today I > used the Intel Active Monitor and it has a window called > Set Sensor Thresholds. There all the voltages can be allowed > to vary a little e.g. 12V is set to vary from 13.2 to 10.8. Same > for CPU core (+1.52V), set to go from 2.325 to 0.725. > There is no variation for the processor fan. > Back tomorrow :-) Just checked my fan and find that there are 3 wires coming from it - black, red and yellow. According to the Intel manual there are 3 wires and it indicates that no fan control exists. The SpeedFan I started up while the Intel monitor was running. I noticed the green line of the SpeedFan varying in length and, while I was watching, the CPU core voltage started to flicker in response. It was responding to the movements of SpeedFan. It even knocked the core voltage down to zero a few times. Then I shut SpeedFan down. I'm not sure that it is refined enough to use with 1.5v products. It also seems that the flickering problems I had earlier were caused by SpeedFan.
From: Paul on 25 Oct 2009 20:15 JD wrote: >> >> Thanks again Paul. I haven't read the above yet. Today I >> used the Intel Active Monitor and it has a window called >> Set Sensor Thresholds. There all the voltages can be allowed >> to vary a little e.g. 12V is set to vary from 13.2 to 10.8. Same >> for CPU core (+1.52V), set to go from 2.325 to 0.725. >> There is no variation for the processor fan. >> Back tomorrow :-) > > Just checked my fan and find that there are 3 wires coming > from it - black, red and yellow. According to the Intel manual > there are 3 wires and it indicates that no fan control exists. > > The SpeedFan I started up while the Intel monitor was running. > I noticed the green line of the SpeedFan varying in length and, > while I was watching, the CPU core voltage started to flicker in > response. It was responding to the movements of SpeedFan. It > even knocked the core voltage down to zero a few times. > Then I shut SpeedFan down. I'm not sure that it is refined > enough to use with 1.5v products. It also seems that the flickering > problems I had earlier were caused by SpeedFan. So are you using a three wire fan on a three pin header ? What combo of parts have you connected together ? If you mention the make and model of motherboard, maybe I can find a picture and see whether there are any components of interest near the fan headers. Paul
From: JD on 25 Oct 2009 21:52 Paul wrote: > JD wrote: > >>> >>> Thanks again Paul. I haven't read the above yet. Today I >>> used the Intel Active Monitor and it has a window called >>> Set Sensor Thresholds. There all the voltages can be allowed >>> to vary a little e.g. 12V is set to vary from 13.2 to 10.8. Same >>> for CPU core (+1.52V), set to go from 2.325 to 0.725. >>> There is no variation for the processor fan. >>> Back tomorrow :-) >> >> Just checked my fan and find that there are 3 wires coming >> from it - black, red and yellow. According to the Intel manual >> there are 3 wires and it indicates that no fan control exists. >> >> The SpeedFan I started up while the Intel monitor was running. >> I noticed the green line of the SpeedFan varying in length and, >> while I was watching, the CPU core voltage started to flicker in >> response. It was responding to the movements of SpeedFan. It >> even knocked the core voltage down to zero a few times. >> Then I shut SpeedFan down. I'm not sure that it is refined >> enough to use with 1.5v products. It also seems that the flickering >> problems I had earlier were caused by SpeedFan. > > So are you using a three wire fan on a three pin header ? > > What combo of parts have you connected together ? > > If you mention the make and model of motherboard, maybe I can > find a picture and see whether there are any components of interest > near the fan headers. > > Paul Thanks again Paul. Motherboard: D845GEBV2 Here is the link to the Intel board connectors http://www.intel.com/support/motherboards/desktop/d845gebv2/sb/cs-020055.htm
From: Paul on 25 Oct 2009 23:41 JD wrote: > Paul wrote: >> JD wrote: >> >>>> >>>> Thanks again Paul. I haven't read the above yet. Today I >>>> used the Intel Active Monitor and it has a window called >>>> Set Sensor Thresholds. There all the voltages can be allowed >>>> to vary a little e.g. 12V is set to vary from 13.2 to 10.8. Same >>>> for CPU core (+1.52V), set to go from 2.325 to 0.725. >>>> There is no variation for the processor fan. >>>> Back tomorrow :-) >>> >>> Just checked my fan and find that there are 3 wires coming >>> from it - black, red and yellow. According to the Intel manual >>> there are 3 wires and it indicates that no fan control exists. >>> >>> The SpeedFan I started up while the Intel monitor was running. >>> I noticed the green line of the SpeedFan varying in length and, >>> while I was watching, the CPU core voltage started to flicker in >>> response. It was responding to the movements of SpeedFan. It >>> even knocked the core voltage down to zero a few times. >>> Then I shut SpeedFan down. I'm not sure that it is refined >>> enough to use with 1.5v products. It also seems that the flickering >>> problems I had earlier were caused by SpeedFan. >> >> So are you using a three wire fan on a three pin header ? >> >> What combo of parts have you connected together ? >> >> If you mention the make and model of motherboard, maybe I can >> find a picture and see whether there are any components of interest >> near the fan headers. >> >> Paul > > Thanks again Paul. > > Motherboard: D845GEBV2 > > Here is the link to the Intel board connectors > > http://www.intel.com/support/motherboards/desktop/d845gebv2/sb/cs-020055.htm > The documentation refers to a fan control ASIC. http://downloadmirror.intel.com/15323/eng/D845GERG2_D845GEBV2_TechProdSpec.pdf The SuperI/O chip appears pretty basic. This one has only two tachometer (RPM) channels. Apparently, a separate chip is used to provide both fan control, and the ability to monitor more fans than the two the LPC47M172 supports. And that ASIC remains unnamed in the above Intel document. ( LPC47M172 ) http://www.smsc.com/index.php?pid=106&tid=249 I found one thread, that mentioned LM85B as a possibility for a separate fan control. http://www.national.com/opf/LM/LM85.html http://www.national.com/images/pf/LM85/20035301.pdf (pretty rich set of functions) It is a 24 pin chip. http://www.national.com/ds/LM/LM85.pdf Chip might look like this. http://www.national.com/packaging/folders/mqa24.html Here is a picture of what Speedfan might show, if this chip was on your board. Apparently it is a manufacturing option. Too bad there isn't an easy way to determine what options are on board. http://i214.photobucket.com/albums/cc178/whelderwheels613/Untitled-2.jpg ( http://www.maximumpc.com/forums/viewtopic.php?t=71981 ) If you had both, they're connected via the following busses. LPC SMBUS (serial, low speed) | | | | LPC47M172 LM85B The difference between the two busses, is that if you use two software programs to monitor the SMBUS, you can get some bad readings in both programs. The SMBUS really needs a software semaphore, so that only one program accesses the bus interface at a time. There is no industry wide agreement on that, and as a result, programs can get corrupted readings if two programs are at work. LPC should be much better in this regard. I would not expect corrupted readings over LPC. What happens on SMBUS, is a second software program, can cause a serial bus transfer to be aborted while the first software program is waiting for its data. (The thing using the bus, could be the BIOS.) In this picture, you can see that both chips are present. The first "Fan1,Fan2" is coming from LPC47M172. The second "Fan1,Fan2,Fan3,Fan4" comes from the LM85B. It is anyone's guess as to how the three fan headers are connected to those six interfaces. http://i214.photobucket.com/albums/cc178/whelderwheels613/untitled-1.jpg So your board is more complicated than the average board. All the motherboards I have here, have only one chip. Perhaps a picture of your board ? http://imgk-a.dena.ne.jp/exk5/20090326/216/128345580_1.jpg In that picture, I can't positively identify the LM85B. It might be up near the top of the picture, to the left of the DIMM sockets. I don't see anything near the fan headers, to do the PWM conversion. The LM85B only has 8ma drive on its open drain PWM control signals, so that isn't enough to drive a fan directly. So there has to be something else to do it. My guess at this point would be, if you see the weird "Fan1,Fan2" "Fan1,Fan2,Fan3,Fan4" in Speedfan, then assume the LM85B is present. And it wouldn't make sense to install the LM85B without also installing any fan header interfacing components. So if the LM85B shows up, you should be able to adjust a fan and hear the speed change. If all you see is "Fan1,Fan2", then you've got the LPC47M172, which only monitors two fans and doesn't attempt to control them. All the control functions would be in the LM85B. My best guess, Paul
From: JD on 27 Oct 2009 15:21
Paul wrote: > JD wrote: >> Paul wrote: >>> JD wrote: >>> >>>>> >>>>> Thanks again Paul. I haven't read the above yet. Today I >>>>> used the Intel Active Monitor and it has a window called >>>>> Set Sensor Thresholds. There all the voltages can be allowed >>>>> to vary a little e.g. 12V is set to vary from 13.2 to 10.8. Same >>>>> for CPU core (+1.52V), set to go from 2.325 to 0.725. >>>>> There is no variation for the processor fan. >>>>> Back tomorrow :-) >>>> >>>> Just checked my fan and find that there are 3 wires coming >>>> from it - black, red and yellow. According to the Intel manual >>>> there are 3 wires and it indicates that no fan control exists. >>>> >>>> The SpeedFan I started up while the Intel monitor was running. >>>> I noticed the green line of the SpeedFan varying in length and, >>>> while I was watching, the CPU core voltage started to flicker in >>>> response. It was responding to the movements of SpeedFan. It >>>> even knocked the core voltage down to zero a few times. >>>> Then I shut SpeedFan down. I'm not sure that it is refined >>>> enough to use with 1.5v products. It also seems that the flickering >>>> problems I had earlier were caused by SpeedFan. >>> >>> So are you using a three wire fan on a three pin header ? >>> >>> What combo of parts have you connected together ? >>> >>> If you mention the make and model of motherboard, maybe I can >>> find a picture and see whether there are any components of interest >>> near the fan headers. >>> >>> Paul >> >> Thanks again Paul. >> >> Motherboard: D845GEBV2 >> >> Here is the link to the Intel board connectors >> >> http://www.intel.com/support/motherboards/desktop/d845gebv2/sb/cs-020055.htm >> > > The documentation refers to a fan control ASIC. > > http://downloadmirror.intel.com/15323/eng/D845GERG2_D845GEBV2_TechProdSpec.pdf > > > The SuperI/O chip appears pretty basic. This one has only two tachometer > (RPM) > channels. Apparently, a separate chip is used to provide both fan > control, and > the ability to monitor more fans than the two the LPC47M172 supports. > And that > ASIC remains unnamed in the above Intel document. > > ( LPC47M172 ) > http://www.smsc.com/index.php?pid=106&tid=249 > > I found one thread, that mentioned LM85B as a possibility for a separate > fan control. > > http://www.national.com/opf/LM/LM85.html > > http://www.national.com/images/pf/LM85/20035301.pdf (pretty rich set of > functions) > > It is a 24 pin chip. > > http://www.national.com/ds/LM/LM85.pdf > > Chip might look like this. > > http://www.national.com/packaging/folders/mqa24.html > > Here is a picture of what Speedfan might show, if this chip was on > your board. Apparently it is a manufacturing option. Too bad there > isn't an easy way to determine what options are on board. > > http://i214.photobucket.com/albums/cc178/whelderwheels613/Untitled-2.jpg > > ( http://www.maximumpc.com/forums/viewtopic.php?t=71981 ) > > If you had both, they're connected via the following busses. > > LPC SMBUS (serial, low speed) > | | > | | > LPC47M172 LM85B > > The difference between the two busses, is that if you use two > software programs to monitor the SMBUS, you can get some bad > readings in both programs. The SMBUS really needs a software > semaphore, so that only one program accesses the bus interface > at a time. There is no industry wide agreement on that, and > as a result, programs can get corrupted readings if two programs > are at work. LPC should be much better in this regard. I would > not expect corrupted readings over LPC. What happens on SMBUS, > is a second software program, can cause a serial bus transfer > to be aborted while the first software program is waiting for > its data. (The thing using the bus, could be the BIOS.) > > In this picture, you can see that both chips are present. > The first "Fan1,Fan2" is coming from LPC47M172. The second > "Fan1,Fan2,Fan3,Fan4" comes from the LM85B. It is anyone's > guess as to how the three fan headers are connected to those > six interfaces. > > http://i214.photobucket.com/albums/cc178/whelderwheels613/untitled-1.jpg > > So your board is more complicated than the average board. All the > motherboards I have here, have only one chip. > > Perhaps a picture of your board ? > > http://imgk-a.dena.ne.jp/exk5/20090326/216/128345580_1.jpg > > In that picture, I can't positively identify the LM85B. It might > be up near the top of the picture, to the left of the DIMM sockets. > I don't see anything near the fan headers, to do the PWM conversion. > The LM85B only has 8ma drive on its open drain PWM control > signals, so that isn't enough to drive a fan directly. > So there has to be something else to do it. > > My guess at this point would be, if you see the weird > "Fan1,Fan2" "Fan1,Fan2,Fan3,Fan4" in Speedfan, then assume > the LM85B is present. And it wouldn't make sense to install > the LM85B without also installing any fan header interfacing > components. So if the LM85B shows up, you should be able > to adjust a fan and hear the speed change. > > If all you see is "Fan1,Fan2", then you've got the LPC47M172, > which only monitors two fans and doesn't attempt to control > them. All the control functions would be in the LM85B. > > My best guess, > Paul Many thanks again Paul. You are a huge help. Yesterday I spent an hour online looking for a good quality picture of the motherboard and failed, even on the Intel web site. The images were far too small to see any writing on the board. Of course I never even dreamed of visiting Japan to look for it ;-) You are a resourceful guy! Were you thinking of a geisha girl when you visited? Then I opened up the computer and had a closer look. The case fan (only one) is connected to the power supply and not to the board. I looked around for other connections and there were no more than appeared on the schematic we looked at a few days ago. I'll change that case fan connection to the motherboard when I get a plug for the connection and some time. I also looked in the area to the rear of the CPU between the AGP card and the power supply. There is the 12V board supply connector and two other small connectors beside the AGP card. These are for ATAPI and the rear case fan - not installed. I started up Speedfan and it does indeed show 4 fans. In the few minutes it was running it knocked the CPU-core voltage reading down to zero 3 times and each time the Intel monitor popped up a warning. That SpeedFan prog makes me worry. The CPU fan has been running and whining at about 4,300 rpm while all the temperatures are showing 25 C. Dumb design this system. I'm still trying to get through all your post above. Back soon, I hope. Thanks again for your efforts. |