CPU cooler advice for P5E3 Premium

Discussion in 'Asus' started by Jim, May 29, 2013.

  1. Jim

    Jim Guest

    I'm about to upgrade my CPU to a Q9550 and want to buy another cooler
    for the cpu, I want to be able to have the option so that when pc is
    idling the fan will slow down to cut noise yet when i do heavy intensive
    cpu work it will of course spin up to a higher rpm.
    I'm unsure how this works though do i have to install some kind of 3rd
    party app from Asus or someone else, is it controlled in the bios, if
    it's a windows app what happens when i'm outside windows for example
    making an image as i say outside windows.

    Jim, May 29, 2013
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  2. Jim

    Rob Guest

    Look under the BIOS menus for Hardware Monitor and set the "CPU
    Fan Control" item to "Profile". Once you do this, an new item
    becomes available, "Fan Profile". Set this to "Optimal" for
    completely automatic CPU fan speed control. This is OS
    Also check whether you need a BIOS upgrade before fitting the
    Q9550 - looks like you need version 505 or later for that CPU.
    Rob, May 29, 2013
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  3. Jim

    Jim Guest

    OK thanks for that Rob I have the latest bios (0803) and i think my new
    cpu will work in there ok, mine is a "Intel Core 2 Quad Processor Q9550
    SLB8V 2.83GHz E0 12M 1333" so i'll go into my bios now and set the settings

    Jim, May 29, 2013
  4. Jim

    Paul Guest

    The only other thing I'd add to Robs answer, is try to get a CPU cooler with
    a four pin fan. To match your four pin CPU header.

    While they make three pin CPU coolers, you may not necessarily
    get a speed control feature by doing that. The four pin header
    helps in that respect (PWM control pin).

    RPM_signal (output from the fan)
    PWM (control input to fan, sets fan speed) <---- want this



    "Power Connector 4 Pin"

    Paul, May 29, 2013
  5. Jim

    Jim Guest

    Thanks Paul, funny you should mention that I'm looking for a new CPU
    cooler now, right now i have no plans to OC but i know i will sooner or
    later to get the most out of my CPU as times goes one so i started
    looking for it yesterday.

    Jim, May 29, 2013
  6. Jim

    Jim Guest

    Thanks Paul well i went for my CPU cooler a Noctua NH-CP12P SE14 which
    does only have a 3 pin and it seems the only way to control the fan in
    any way is with a couple of resistors that alter the input voltage,
    however i do have a Reeven Six Eyes fan controller so i may use that,
    which is a bit of a bummer as i wanted the cpu cooler to be automated to
    some degree, oh well such is life i guess i'll set up some kind of
    software that runs in the systray and sounds an alarm if it goes over a
    certain temp.

    Jim, Jun 2, 2013
  7. Jim

    Paul Guest

    So electrically, what you'd want, is something that translates four
    pin PWM 25KHz signal, into three pin analog +12V.

    Example here.


    "The Nanoxia 3-Pin to 4-Pin PWM fan controller is a unique
    adapter that allows you to plug any standard 3-Pin fan
    into your PWM motherboard and have your motherboard
    control your standard fan as if it were a PWM fan!"

    Effectively, that would be using the circuit that comes
    inside the hub of a four wire cpu fan. They're asking $13
    for it, but it would be cheaper than that, to make it.

    The inside of it, is pretty cheesy looking.


    This thread here, addresses the general topic. If I'm reading
    this right, the Nanoxia "quantizes" the fan speed setting.
    The motherboard sends a continuously variable fan speed
    signal, but the Nanoxia chooses to send out 5.1, 6.7, 8.0, 9.3,
    or 10.4 volts (never goes to 12V, due to the drop across
    the pass transistor).


    Whereas this kind of design, is continuously variable, just
    like the motherboard.


    I expect both designs, will be kicking out a bit of heat while
    they do the conversion.

    So it is possible to do conversion, if you're sufficiently
    motivated to track down a good design. That preserves
    all the design intent, of the 4 pin, but with a 3 pin

    Paul, Jun 2, 2013
  8. Jim

    Bob F Guest

    Can't 3 pin fans be controlled by the bios/motherboard? I do that on one of
    Bob F, Jun 5, 2013
  9. Jim

    Paul Guest

    There are two generations of control methods. But they both boil down
    to the same thing. Just slight differences as to where the conversion
    is done.

    On a three pin fan, you want to vary the +12V supply voltage to the fan.
    The three pin fan, generally the fan is "just a DC motor", so changing
    the voltage makes some difference to the speed.

    Your motherboard, would have a transistor of some sort, next to the
    three pin CPU fan header. The signal coming to that transistor is
    PWM, because a PWM method saturates the transistor, keeping power
    dissipation in the transistor low. You could easily use
    other, non-PWM methods to create a voltage, but those
    are less common as a methodology. (I use diodes to drop voltage
    here, and have also on occasion used a 78xx family regulator for
    reducing fan speed.)

    Now, on the four pin fan header, Intel says you're supposed to
    keep the 12V pin at precisely 12V. They say that, because they
    know there is a transistor inside the fan hub, and it works best
    running at 12V. If you feed a reduced voltage to the fan,
    at the same time as you also feed it a PWM signal instructing
    the fan to slow down, the transistor doesn't get biased properly.
    The hub of the fan starts to get warm, or hot.

    So with the four pin interface, the fan gets a constant +12V
    source, as well as the PWM logic signal. The signal runs at
    25KHz, the intent being, any acoustic noise made as a byproduct
    of that signal, is above human hearing. The PWM signal works
    the same way as the old three pin, motherboard-centric solution
    would have worked. The PWM signal operates on a saturated
    transistor inside the fan hub, and the output voltage from
    that operation, feeds the fan motor.

    So all Intel really did, was push the expense of that transistor,
    to the fan manufacturer, and away from the motherboard manufacturer.

    There were some "transition" motherboards, where the four pin fan
    header supported both methods. But the user was responsible for
    setting a control in the BIOS properly. The user had to set it
    to "three pin", when a three pin fan was present (so the +12V
    gets dialed down). Then, if a four pin fan is being used, the
    user has to remember to change the BIOS setting as well, to PWM.
    Then, control is purely via the PWM logic signal, and the +12V
    from the motherboard, stays at a constant 12V level. There were a
    fair number of boards with that option, so you may still run
    into some. The user in that case, is responsible for not
    setting the BIOS to "three pin mode", when a four pin fan
    is present (as Intel wants the 4 pin 12V pin, to run at 12V).

    Paul, Jun 5, 2013
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