What's the PWR_FAN header for?

Discussion in 'Asus' started by milleron, Jul 29, 2005.

  1. milleron

    milleron Guest

    On my A8N-SLI Premium, one of the fan headers is labeled "PWR-FAN."
    I've assumed that it's the proper place to connect the three-pin fan
    header plug from my PSU (Antec TruePower II). I don't think the
    manual says anything more about it than to label it.
    Clearly, it would NOT be there to provide power to that particular
    fan, so I deduce that it's there to provide rpm monitoring for the PSU
    fan.

    But the only fan speeds I can find reported are the CPU and the
    CHA1_FAN. This is true in BIOS, Asus Probe, Lavalys Everest, and
    nVidia Monitor. What am I missing or misunderstanding here?

    Thanks,

    Ron
     
    milleron, Jul 29, 2005
    #1
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  2. milleron

    Ed Guest

    On Fri, 29 Jul 2005 01:39:32 GMT, milleron
    <> wrote:

    >On my A8N-SLI Premium, one of the fan headers is labeled "PWR-FAN."
    >I've assumed that it's the proper place to connect the three-pin fan
    >header plug from my PSU (Antec TruePower II). I don't think the
    >manual says anything more about it than to label it.
    >Clearly, it would NOT be there to provide power to that particular
    >fan, so I deduce that it's there to provide rpm monitoring for the PSU
    >fan.
    >
    >But the only fan speeds I can find reported are the CPU and the
    >CHA1_FAN. This is true in BIOS, Asus Probe, Lavalys Everest, and
    >nVidia Monitor. What am I missing or misunderstanding here?
    >
    >Thanks,
    >
    >Ron


    See 2-24 of the manual (PDF), it's just another fan header.
     
    Ed, Jul 29, 2005
    #2
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  3. milleron

    timmy Guest

    thats correct. no voltage, just a psu rpm monitor...

    On Fri, 29 Jul 2005 01:39:32 GMT, milleron
    <> wrote:

    >On my A8N-SLI Premium, one of the fan headers is labeled "PWR-FAN."
    >I've assumed that it's the proper place to connect the three-pin fan
    >header plug from my PSU (Antec TruePower II). I don't think the
    >manual says anything more about it than to label it.
    >Clearly, it would NOT be there to provide power to that particular
    >fan, so I deduce that it's there to provide rpm monitoring for the PSU
    >fan.
    >
    >But the only fan speeds I can find reported are the CPU and the
    >CHA1_FAN. This is true in BIOS, Asus Probe, Lavalys Everest, and
    >nVidia Monitor. What am I missing or misunderstanding here?
    >
    >Thanks,
    >
    >Ron
     
    timmy, Jul 29, 2005
    #3
  4. milleron

    Paul Guest

    In article <>,
    wrote:

    > On my A8N-SLI Premium, one of the fan headers is labeled "PWR-FAN."
    > I've assumed that it's the proper place to connect the three-pin fan
    > header plug from my PSU (Antec TruePower II). I don't think the
    > manual says anything more about it than to label it.
    > Clearly, it would NOT be there to provide power to that particular
    > fan, so I deduce that it's there to provide rpm monitoring for the PSU
    > fan.
    >
    > But the only fan speeds I can find reported are the CPU and the
    > CHA1_FAN. This is true in BIOS, Asus Probe, Lavalys Everest, and
    > nVidia Monitor. What am I missing or misunderstanding here?
    >
    > Thanks,
    >
    > Ron


    The Premium manual lists CPU, CHA1, CHIP as the three fan
    speed monitoring channels. It would seem they ran out of
    channels, and considered the CHIP header to be more important
    than the PSU header. Now, normally, there would be no need
    to put +12V on that header, but perhaps +12V and GND are the
    only connections.

    Assuming your board has an ITE IT8712 hardware monitor chip,
    there are actually five fan control channels and five fan
    monitoring channels. If the motherboard has a GAME/MIDI header,
    two pins from the fan control group and two pins from the
    fan monitoring group, are hijacked to make joystick interface
    pins. That leaves three channels of fan control and three
    channels of RPM monitoring. Seeing as the manual lists
    CPU, CHA1, CHIP as the monitor headers, any other headers
    are at best just power plugs for fans. You could check to see
    if they have power, by plugging in a fan (with the power off!).

    Paul
     
    Paul, Jul 29, 2005
    #4
  5. milleron

    milleron Guest

    On Fri, 29 Jul 2005 01:47:16 -0400, (Paul) wrote:

    >In article <>,
    > wrote:
    >
    >> On my A8N-SLI Premium, one of the fan headers is labeled "PWR-FAN."
    >> I've assumed that it's the proper place to connect the three-pin fan
    >> header plug from my PSU (Antec TruePower II). I don't think the
    >> manual says anything more about it than to label it.
    >> Clearly, it would NOT be there to provide power to that particular
    >> fan, so I deduce that it's there to provide rpm monitoring for the PSU
    >> fan.
    >>
    >> But the only fan speeds I can find reported are the CPU and the
    >> CHA1_FAN. This is true in BIOS, Asus Probe, Lavalys Everest, and
    >> nVidia Monitor. What am I missing or misunderstanding here?
    >>
    >> Thanks,
    >>
    >> Ron

    >
    >The Premium manual lists CPU, CHA1, CHIP as the three fan
    >speed monitoring channels. It would seem they ran out of
    >channels, and considered the CHIP header to be more important
    >than the PSU header. Now, normally, there would be no need
    >to put +12V on that header, but perhaps +12V and GND are the
    >only connections.
    >
    >Assuming your board has an ITE IT8712 hardware monitor chip,
    >there are actually five fan control channels and five fan
    >monitoring channels. If the motherboard has a GAME/MIDI header,
    >two pins from the fan control group and two pins from the
    >fan monitoring group, are hijacked to make joystick interface
    >pins. That leaves three channels of fan control and three
    >channels of RPM monitoring. Seeing as the manual lists
    >CPU, CHA1, CHIP as the monitor headers, any other headers
    >are at best just power plugs for fans. You could check to see
    >if they have power, by plugging in a fan (with the power off!).
    >
    > Paul


    Thanks, Paul. So it looks as though the header marked "PWR_FAN" is,
    in reality, for any fan OTHER THAN the "PWR FAN" because all the PSU
    fan requires is rpm monitoring, but the only thing that header
    actually provides is power. Asus was really stupid on this one, then.

    Ron
     
    milleron, Jul 29, 2005
    #5
  6. milleron

    milleron Guest

    On Thu, 28 Jul 2005 22:36:56 -0500, Ed <> wrote:

    >On Fri, 29 Jul 2005 01:39:32 GMT, milleron
    ><> wrote:
    >
    >>On my A8N-SLI Premium, one of the fan headers is labeled "PWR-FAN."
    >>I've assumed that it's the proper place to connect the three-pin fan
    >>header plug from my PSU (Antec TruePower II). I don't think the
    >>manual says anything more about it than to label it.
    >>Clearly, it would NOT be there to provide power to that particular
    >>fan, so I deduce that it's there to provide rpm monitoring for the PSU
    >>fan.
    >>
    >>But the only fan speeds I can find reported are the CPU and the
    >>CHA1_FAN. This is true in BIOS, Asus Probe, Lavalys Everest, and
    >>nVidia Monitor. What am I missing or misunderstanding here?
    >>
    >>Thanks,
    >>
    >>Ron

    >
    >See 2-24 of the manual (PDF), it's just another fan header.


    Thanks for the reply, but I did read the manual before posting.
    Although the PWR_FAN header is pictured there on 2-24, it certainly
    does not state that it's "just another fan header" and definitely does
    not say anything about its rpm-monitoring capability. In fact, it
    gives no information about it (other than that it's not governed by
    Q-Fan), which is why I posted the question here.



    Ron
     
    milleron, Jul 29, 2005
    #6
  7. milleron

    milleron Guest

    On Fri, 29 Jul 2005 04:19:58 GMT, timmy <> wrote:

    >thats correct. no voltage, just a psu rpm monitor...


    If it's an rpm monitor, where is the rpm result reported?????

    >
    >On Fri, 29 Jul 2005 01:39:32 GMT, milleron
    ><> wrote:
    >
    >>On my A8N-SLI Premium, one of the fan headers is labeled "PWR-FAN."
    >>I've assumed that it's the proper place to connect the three-pin fan
    >>header plug from my PSU (Antec TruePower II). I don't think the
    >>manual says anything more about it than to label it.
    >>Clearly, it would NOT be there to provide power to that particular
    >>fan, so I deduce that it's there to provide rpm monitoring for the PSU
    >>fan.
    >>
    >>But the only fan speeds I can find reported are the CPU and the
    >>CHA1_FAN. This is true in BIOS, Asus Probe, Lavalys Everest, and
    >>nVidia Monitor. What am I missing or misunderstanding here?
    >>
    >>Thanks,
    >>
    >>Ron


    Ron
     
    milleron, Jul 29, 2005
    #7
  8. milleron

    RonK Guest

    Some power supplies have a separate lead that can be plugged into the Fan
    Header on the motherboard. The motherboard will then controll the power
    supply fan or it will just monitor the speed of the fan.


    "milleron" <> wrote in message
    news:...
    > On my A8N-SLI Premium, one of the fan headers is labeled "PWR-FAN."
    > I've assumed that it's the proper place to connect the three-pin fan
    > header plug from my PSU (Antec TruePower II). I don't think the
    > manual says anything more about it than to label it.
    > Clearly, it would NOT be there to provide power to that particular
    > fan, so I deduce that it's there to provide rpm monitoring for the PSU
    > fan.
    >
    > But the only fan speeds I can find reported are the CPU and the
    > CHA1_FAN. This is true in BIOS, Asus Probe, Lavalys Everest, and
    > nVidia Monitor. What am I missing or misunderstanding here?
    >
    > Thanks,
    >
    > Ron
     
    RonK, Jul 29, 2005
    #8
  9. "RonK" <> wrote in message
    news:tZwGe.6718$...
    > Some power supplies have a separate lead that can be plugged into the Fan
    > Header on the motherboard. The motherboard will then controll the power
    > supply fan or it will just monitor the speed of the fan.
    >


    Yes, my Antec NeoPower 480 has a 3-pin fan sensor on it.
    The trouble is that the A8N-SLI Deluxe does not give you the ability to read
    the RPM anywhere.
    There is nothing in the BIOS, Asus Probe does not show the reading either.
    So far I have tried:

    Sandra
    Speed Fan
    MBM5
    Everest

    And not one of them is able to read the information form the header.
     
    Pete M Williams, Jul 29, 2005
    #9
  10. milleron

    Tom Dauphin Guest

    On the P4C800 the header reads the power supply fan fine, if you have a
    supply with the lead. It outputs it to the Asus Probe program. Funny they
    wouldn't do that on your board as well.
    "milleron" <> wrote in message
    news:...
    > On Fri, 29 Jul 2005 01:47:16 -0400, (Paul) wrote:
    >
    >>In article <>,
    >> wrote:
    >>
    >>> On my A8N-SLI Premium, one of the fan headers is labeled "PWR-FAN."
    >>> I've assumed that it's the proper place to connect the three-pin fan
    >>> header plug from my PSU (Antec TruePower II). I don't think the
    >>> manual says anything more about it than to label it.
    >>> Clearly, it would NOT be there to provide power to that particular
    >>> fan, so I deduce that it's there to provide rpm monitoring for the PSU
    >>> fan.
    >>>
    >>> But the only fan speeds I can find reported are the CPU and the
    >>> CHA1_FAN. This is true in BIOS, Asus Probe, Lavalys Everest, and
    >>> nVidia Monitor. What am I missing or misunderstanding here?
    >>>
    >>> Thanks,
    >>>
    >>> Ron

    >>
    >>The Premium manual lists CPU, CHA1, CHIP as the three fan
    >>speed monitoring channels. It would seem they ran out of
    >>channels, and considered the CHIP header to be more important
    >>than the PSU header. Now, normally, there would be no need
    >>to put +12V on that header, but perhaps +12V and GND are the
    >>only connections.
    >>
    >>Assuming your board has an ITE IT8712 hardware monitor chip,
    >>there are actually five fan control channels and five fan
    >>monitoring channels. If the motherboard has a GAME/MIDI header,
    >>two pins from the fan control group and two pins from the
    >>fan monitoring group, are hijacked to make joystick interface
    >>pins. That leaves three channels of fan control and three
    >>channels of RPM monitoring. Seeing as the manual lists
    >>CPU, CHA1, CHIP as the monitor headers, any other headers
    >>are at best just power plugs for fans. You could check to see
    >>if they have power, by plugging in a fan (with the power off!).
    >>
    >> Paul

    >
    > Thanks, Paul. So it looks as though the header marked "PWR_FAN" is,
    > in reality, for any fan OTHER THAN the "PWR FAN" because all the PSU
    > fan requires is rpm monitoring, but the only thing that header
    > actually provides is power. Asus was really stupid on this one, then.
    >
    > Ron
     
    Tom Dauphin, Jul 30, 2005
    #10
  11. milleron

    milleron Guest

    On Sat, 30 Jul 2005 15:44:17 GMT, "Tom Dauphin"
    <> wrote:

    >On the P4C800 the header reads the power supply fan fine, if you have a
    >supply with the lead. It outputs it to the Asus Probe program. Funny they
    >wouldn't do that on your board as well.


    Well, this board does have a game-port header, so, as Paul explained,
    Asus seems to have pirated a connection from the PWR_FAN header to
    make the game port functional. It's the best explanation I've had so
    far. I have my PSU plug connected to the PWR_FAN header, and there's
    no readout ANYwhere.
    Too bad, because I'm really curious about how much variation there is
    in the TruePower II's fan.
    Interestingly, Paul has a reference stating that on my board, the CHIP
    header provides monitoring. However, I do have a small 80mm fan with
    rpm sensing connected there, and there's no readout for that one,
    either. The only two I can see are CPU and CHA1_FAN which, probably
    not coincidentally, are the only two headers on this board controlled
    by Q-Fan.

    >"milleron" <> wrote in message
    >news:...
    >> On Fri, 29 Jul 2005 01:47:16 -0400, (Paul) wrote:
    >>
    >>>In article <>,
    >>> wrote:
    >>>
    >>>> On my A8N-SLI Premium, one of the fan headers is labeled "PWR-FAN."
    >>>> I've assumed that it's the proper place to connect the three-pin fan
    >>>> header plug from my PSU (Antec TruePower II). I don't think the
    >>>> manual says anything more about it than to label it.
    >>>> Clearly, it would NOT be there to provide power to that particular
    >>>> fan, so I deduce that it's there to provide rpm monitoring for the PSU
    >>>> fan.
    >>>>
    >>>> But the only fan speeds I can find reported are the CPU and the
    >>>> CHA1_FAN. This is true in BIOS, Asus Probe, Lavalys Everest, and
    >>>> nVidia Monitor. What am I missing or misunderstanding here?
    >>>>
    >>>> Thanks,
    >>>>
    >>>> Ron
    >>>
    >>>The Premium manual lists CPU, CHA1, CHIP as the three fan
    >>>speed monitoring channels. It would seem they ran out of
    >>>channels, and considered the CHIP header to be more important
    >>>than the PSU header. Now, normally, there would be no need
    >>>to put +12V on that header, but perhaps +12V and GND are the
    >>>only connections.
    >>>
    >>>Assuming your board has an ITE IT8712 hardware monitor chip,
    >>>there are actually five fan control channels and five fan
    >>>monitoring channels. If the motherboard has a GAME/MIDI header,
    >>>two pins from the fan control group and two pins from the
    >>>fan monitoring group, are hijacked to make joystick interface
    >>>pins. That leaves three channels of fan control and three
    >>>channels of RPM monitoring. Seeing as the manual lists
    >>>CPU, CHA1, CHIP as the monitor headers, any other headers
    >>>are at best just power plugs for fans. You could check to see
    >>>if they have power, by plugging in a fan (with the power off!).
    >>>
    >>> Paul

    >>
    >> Thanks, Paul. So it looks as though the header marked "PWR_FAN" is,
    >> in reality, for any fan OTHER THAN the "PWR FAN" because all the PSU
    >> fan requires is rpm monitoring, but the only thing that header
    >> actually provides is power. Asus was really stupid on this one, then.
    >>
    >> Ron

    >


    Ron
     
    milleron, Jul 30, 2005
    #11
  12. milleron

    Tom Dauphin Guest

    I've got an Antec 480 and it typically runs at about 1850 rpm at idle and
    maybe 2300 rpm in 2D Apps. In 3D games it typically runs at about 4500 rpm.
    This is with ambiant room temps of about 82 degrees this time of year.
    "milleron" <> wrote in message
    news:...
    > On Sat, 30 Jul 2005 15:44:17 GMT, "Tom Dauphin"
    > <> wrote:
    >
    >>On the P4C800 the header reads the power supply fan fine, if you have a
    >>supply with the lead. It outputs it to the Asus Probe program. Funny they
    >>wouldn't do that on your board as well.

    >
    > Well, this board does have a game-port header, so, as Paul explained,
    > Asus seems to have pirated a connection from the PWR_FAN header to
    > make the game port functional. It's the best explanation I've had so
    > far. I have my PSU plug connected to the PWR_FAN header, and there's
    > no readout ANYwhere.
    > Too bad, because I'm really curious about how much variation there is
    > in the TruePower II's fan.
    > Interestingly, Paul has a reference stating that on my board, the CHIP
    > header provides monitoring. However, I do have a small 80mm fan with
    > rpm sensing connected there, and there's no readout for that one,
    > either. The only two I can see are CPU and CHA1_FAN which, probably
    > not coincidentally, are the only two headers on this board controlled
    > by Q-Fan.
    >
    >>"milleron" <> wrote in message
    >>news:...
    >>> On Fri, 29 Jul 2005 01:47:16 -0400, (Paul) wrote:
    >>>
    >>>>In article <>,
    >>>> wrote:
    >>>>
    >>>>> On my A8N-SLI Premium, one of the fan headers is labeled "PWR-FAN."
    >>>>> I've assumed that it's the proper place to connect the three-pin fan
    >>>>> header plug from my PSU (Antec TruePower II). I don't think the
    >>>>> manual says anything more about it than to label it.
    >>>>> Clearly, it would NOT be there to provide power to that particular
    >>>>> fan, so I deduce that it's there to provide rpm monitoring for the PSU
    >>>>> fan.
    >>>>>
    >>>>> But the only fan speeds I can find reported are the CPU and the
    >>>>> CHA1_FAN. This is true in BIOS, Asus Probe, Lavalys Everest, and
    >>>>> nVidia Monitor. What am I missing or misunderstanding here?
    >>>>>
    >>>>> Thanks,
    >>>>>
    >>>>> Ron
    >>>>
    >>>>The Premium manual lists CPU, CHA1, CHIP as the three fan
    >>>>speed monitoring channels. It would seem they ran out of
    >>>>channels, and considered the CHIP header to be more important
    >>>>than the PSU header. Now, normally, there would be no need
    >>>>to put +12V on that header, but perhaps +12V and GND are the
    >>>>only connections.
    >>>>
    >>>>Assuming your board has an ITE IT8712 hardware monitor chip,
    >>>>there are actually five fan control channels and five fan
    >>>>monitoring channels. If the motherboard has a GAME/MIDI header,
    >>>>two pins from the fan control group and two pins from the
    >>>>fan monitoring group, are hijacked to make joystick interface
    >>>>pins. That leaves three channels of fan control and three
    >>>>channels of RPM monitoring. Seeing as the manual lists
    >>>>CPU, CHA1, CHIP as the monitor headers, any other headers
    >>>>are at best just power plugs for fans. You could check to see
    >>>>if they have power, by plugging in a fan (with the power off!).
    >>>>
    >>>> Paul
    >>>
    >>> Thanks, Paul. So it looks as though the header marked "PWR_FAN" is,
    >>> in reality, for any fan OTHER THAN the "PWR FAN" because all the PSU
    >>> fan requires is rpm monitoring, but the only thing that header
    >>> actually provides is power. Asus was really stupid on this one, then.
    >>>
    >>> Ron

    >>

    >
    > Ron
     
    Tom Dauphin, Jul 30, 2005
    #12
  13. milleron

    timmy Guest

    are you sure it's not a "vre" header ? Maybe it is in fact just a
    miss- labelled power fan header...

    Like paul suggested, just plug a fan into it and see if it is powered.

    Another thing you could try is disconnect the chassis fan header and
    hookup the fan to the pwrfan header...now check you bios. It may be
    visible there now and the limitation is that only 2 headers may be
    reported at any one time. This was the case with an intel board I
    had...
    FYI

    On Fri, 29 Jul 2005 19:21:38 GMT, milleron
    <> wrote:

    >On Fri, 29 Jul 2005 04:19:58 GMT, timmy <> wrote:
    >
    >>thats correct. no voltage, just a psu rpm monitor...

    >
    >If it's an rpm monitor, where is the rpm result reported?????
    >
    >>
    >>On Fri, 29 Jul 2005 01:39:32 GMT, milleron
    >><> wrote:
    >>
    >>>On my A8N-SLI Premium, one of the fan headers is labeled "PWR-FAN."
    >>>I've assumed that it's the proper place to connect the three-pin fan
    >>>header plug from my PSU (Antec TruePower II). I don't think the
    >>>manual says anything more about it than to label it.
    >>>Clearly, it would NOT be there to provide power to that particular
    >>>fan, so I deduce that it's there to provide rpm monitoring for the PSU
    >>>fan.
    >>>
    >>>But the only fan speeds I can find reported are the CPU and the
    >>>CHA1_FAN. This is true in BIOS, Asus Probe, Lavalys Everest, and
    >>>nVidia Monitor. What am I missing or misunderstanding here?
    >>>
    >>>Thanks,
    >>>
    >>>Ron

    >
    >Ron
     
    timmy, Aug 1, 2005
    #13
  14. On Sat, 30 Jul 2005 15:58:32 GMT, milleron <>
    wrote:

    > I have my PSU plug connected to the PWR_FAN header, and there's
    >no readout ANYwhere.
    >Too bad, because I'm really curious about how much variation there is
    >in the TruePower II's fan.


    Just plug it into the RPM-monitored header that isn't the CPU fan. Since
    the PSU fan isn't powered by header, any fan-speed control of the board
    won't affect it, you'll just get the current rpm readout.

    Cheers - Jaimie
     
    Jaimie Vandenbergh, Aug 3, 2005
    #14
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