Q-fan settings and buying a variable speed detectable and variable fan: WTF

Discussion in 'Asus' started by kgs, Jan 3, 2004.

  1. kgs

    kgs Guest

    I just bought an Asus P4C800-E deluxe, but don't have a cpu or ram yet. So:

    I need to buy a fan with 3-wire; I've got a couple 2-wire already.

    A 2-wire type fan has power supplied only, and the power is connected not to
    the mobo, but via a molex connector to the wires that come directly from
    the power supply, on the same power chain that powers the CD/HD/Floppy. If
    you have a connector for CHA_FAN on the mobo it is probably a 3-wire
    type,which allows mionitoring of the fans speed as well as supplying the
    power, all on the same 3-pin plug, at the mobo.

    I am going to try to get to the bottom of the fan speed monitoring problem
    with respect to variable speed fan type options. They are cheap. For
    instance,
    Vantec has an 80mm that has the following specs: 23.8-41.6 cfm,
    25.5-37.5dBA, 1950-3400 RPM.

    These are the things you have to look for
    because Asus has alluded to Q-fan as " The Asus Q-fan technology smartly
    adjusts the fan speeds according to the system loading to ensure quiet, cool
    and efficient operation".

    I don't know if this is just alarm/ set it yourself, etc...
    Probably hocus pocus. There is nothing on the web site I can find. I could
    read it a thousand times and not know the first thing about what they're
    talking about. Anybody got any info about this?

    Are all fans adjustable? i.e. just change the power supplied and that
    changes the speed. Are the resulting speeds always determinable? Do you
    need a special variable adjustable, and variable monitorable fan type? In
    theory I assume that at least all of the fans I will discuss here are in
    fact monitorable using pcProbe, or whatever it is called now, whether in
    bios, or the os, or both.

    If the problem arises, how does a layman determine the correct heat setting
    to use, e.g. Intel site? Anybody got any pointers. e.g H65C, M55C, L35C.
    How do you get the specific information to apply to your specific processor.
    Especially 2.4C, 2.6C, or 2.8C(don't know yet): are all similarly oc'able?


    This could mean many things: when the computer shuts down, when the alarm
    goes off, when the fan comes on, when the fan goes off, the minimum
    allowable fan setting, the maximum fan speed setting, or any countless
    combination... I can think of a similar number of good reasons for having
    this technology.

    I think the ideal possiblity is, since the mobo has cpu and mobo temp sensor
    settings, and obviously (some?)fan speeds are adjustable, that you use the
    feature settings this is designed for to set the max allowable temp that you
    want to allow, before (i) the fan speeds up, or turns on, (ii) the settings
    causing the excess heat are changed, (iii) a warning is given, (iv) the
    computer shuts down... You see I'm back to the beginning again.

    The bios options under Power for Q-Fan are enable/disable
    When enabled select Fan Spped Ratio; any one of: 11/16 12/16 13/16 14/16
    15/16. 11/16 is the minimum fan speed ratio. Select a higher ratio if you
    installed additional devices and the system requires more ventilation.

    Can someone who knows please clear this up


    BTW, the POWMAX LP-8800C 350W ATX psu I have says on the box "supports fan
    speed monitoring". Other than the connections for the disk drives, it only
    has a 4-pin and 20-pin connector, which I think would be standard for this
    type anyways. Will I get a power supply fan speed with this? Does the
    signal come through the 20- or 4- pin connection. Alternatively, there is
    also a 3-pin PWR_FAN, as well as the CHA_FAN and CPU_FAN. The CHS and PWR
    fans obvoiously get the job done of determining their fan speeds through
    these 3-pin connectors, which also supply the power to the fans. Is it
    possible that this would connect into the psu's fan. If this is the case,
    could I have this option, and what would I have to do to enable it. What
    were they talking about when they said "supports fan speed monitoring"?
     
    kgs, Jan 3, 2004
    #1
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  2. kgs

    Mistoffolees Guest

    There are very few problems with properly mounted fans, regardless of
    their location. In all of our recent installations, the heatsink/fan
    that is supplied with the retail Intel P4 CPU's have done quite well,
    although a little noisy, depending on the computer case. These Intel
    fans are 3-wire, the third wire is the tachometer lead, but also have
    their own thermal control. Consequently, the Q-Fan setting is disabled
    with these fans. It is Winter in Southern California but the CPU's run
    between 25 to 35 deg. C. under normal load at around 2,900 RPM.

    We have also played with the ThermalTake P4 Xaser heatsink/fans under
    normal speed and variable speed control. Normal speed is high and loud
    but same temperatures are achieved at around 3,100 RPM.

    Bottom line is that Q-Fan is effective mainly for high-RPM HSF's that
    do not have its own thermal control...just to minimize the noise as
    the HSF's tend to be effective in a well-ventilated case. A good CPU
    temp for a P4 CPU can range from 25 to 50 deg C., depending on the
    load conditions. And optimum fan speed for HSF's with manual controllers
    is whatever obtains minimal fan noise at acceptable operating temp.

    As for the other motherboard fan leads, there is no speed control for
    fans connected to PWR or CHA. The third pin is for the tachometer.
    And the PSU fan is normally independent of the motherboard.
     
    Mistoffolees, Jan 3, 2004
    #2
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  3. kgs

    Paul Guest

    It is hard to tell from the photo of the motherboard in the manual,
    but the board could be using a Winbond W83627THF SuperI/O chip, which
    includes a hardware monitor. The datasheet I have was downloaded from:

    http://www.winbond-usa.com/products/winbond_products/pdfs/PCIC/627thf.pdf

    On page 115, it says this chip only has PWM fan control outputs for
    up to two fans, so three motherboard fans cannot be controlled
    independently. Also, this chip is a "dumb" fan controller, in that
    software has to update the "duty cycle" setting every time the fan speed
    needs to be adjusted. Maybe this is done by the BIOS code - I have
    no way of knowing that for sure. It is also difficult to guess at
    what the control algorithm would be in the BIOS. The BIOS has the
    ability to monitor some temperatures, and based on this the BIOS could
    adjust the duty cycle - the BIOS could even monitor the fan RPMs recorded
    by the Winbond chip, and adjust the duty cycle to achieve a fixed fan
    speed at a given motherboard temperature. To know more, I would have to
    connect a meter to the fan voltage and watch what happens when the processor
    heats up.

    Note that when using the retail Intel HSF provided with your processor,
    the Intel fan also has a temperature control feature. There is a thermistor
    on the Intel HSF that measures air temperature. The thermistor is monitored
    by a control circuit inside the Intel fan, and the voltage to the fan
    is adjusted based on the ambient temp in the case.

    With the two control features enabled, sometimes you can get extreme swings
    in fan speed, such as the inability to get a good maximum fan speed when
    the processor is running hot. To fix this, you could either buy a CPU fan
    that doesn't monitor the air temperature, you could short out the thermistor
    on the Intel fan to get it to run at higher speed, or you could disable
    Q-fan and rely on the Intel HSF thermistor to make the necessary adjustment.

    Because a fan without the tachometer output is a few cents cheaper to make,
    the market is flooded with two wire fans. This is unfortunate, as if all the
    fans had tacho output, you wouldn't have to do a lot of searching to find
    a good fan with RPM monitor.

    The original posters questions:
    Fan speed changes in proportion to voltage. Many fans are guaranteed to
    spin between 7 volts and 12 volts supplied. Since the fan speed changes
    in relation to the resistance to air flow, the speed is not regulated and
    there can be large variations from unit to unit. To regulate the fan speed,
    there are regulator chips (Maxim makes one) that watch the tachometer
    output and adjust the voltage to achieve a constant speed - I've only
    seen one product that uses a chip like that. Fans don't list this voltage
    versus speed thing as a feature as such, but motherboards or other devices
    vary the voltage to the fan, if a noise control feature is desired. As
    the original poster noted, not all fans have the tacho output, so neither
    hardware nor software closed loop control of speed is possible with a dumb
    two pin fan.

    Fan voltage can be adjusted via a variable resistor (many drive bay
    controllers do that) or a variable voltage can be achieved by using
    pulse width modulation (PWM) and a capacitor as an integrator. The PWM
    method is efficient and doesn't heat up the transistor used to switch
    the current appreciably - this is why PWM is used on a motherboard, to
    avoid yet another source of heat. Since the transistor is small, there
    is usually a limit to the current that can be controlled via PWM -
    exceeding the current limit burns out the transistor and leaves you with
    a dead fan header.

    HTH,
    Paul
     
    Paul, Jan 4, 2004
    #3
  4. Just as a footnote, i own this board, and CPU-Z confirms that the Winbond is
    in fact a W83627THF.
     
    Philip Callan, Jan 4, 2004
    #4
  5. kgs

    kgs Guest

    "As for the other motherboard fan leads, there is no speed control for
    fans connected to PWR or CHA. The third pin is for the tachometer.
    And the PSU fan is normally independent of the motherboard."

    On the p4c800-e dlx there are 3-pin power & monitoring connectors for
    cpu/cha & pwr fans.

    There is also a thermal thermal sensor cable to conect to the psu.

    The key word here I guess is CONTROL. I have yet to discover if there is a
    control for the cpu fan. Is this in fact true, and is this adjusted by the
    asus BIOS and/or software?

    My psu box POWMAX LP-8800C says "supports fan speed monitoring" ! Does this
    mean it allows others to achieve this?

    So for case fan options, now that I am about to buy, and everything is
    riding on this as of now, to connect to the mobo CHA_FAN all I need is a
    3-wire fan and that will allow tach monitoring, but no control, which is not
    not an option w/ asus bios, or o/ s/w with anything other than the CPU_FAN
    for the purpose o running a cool and quiet pc. All I need to find out is
    what bios, or o/ s/w does exactly. These fans are pretty cheap even in red.

    I'll need to figure out what this means:
    I want to know what monitoring
    is done by asus, and what the result is when selecting a different fan.
    Fans have differnt cfms/rpms/dBAs/VAs, and POSSIBLY the ability to monitor
    and change these values. One fan will not behave the same as another. p2-27
    of the p2c800-e deluxe manual says the "3-pin CPU_FAN, PWR_FAN, CHA_FAN fan
    connectors support cooling fans of 350mA~740mA (8.88Wmax.) or a total of
    1A~2.22A (26.64W max.) at +12V". I don't know if is the variable
    output(controllable range), or if any value in between is the max fan rating
    to connect, and if it makes a diffrence if the fan types allows supports
    monitoring and adjustment, or if all 3-wire fans do all of the above. What
    about adding other built-in fan functionality inline with the 3-pin at the
    mobo. I want cool, but I don't neccesarily want to bypass an already
    existing technology, especially since I am ignorant as to the cause and
    effects, and needs. What about attaching a reostat & tach inline on the
    CHA_FAN jack on the mobo.

    Can you split the fan load at the CHA-FAN connector, (and monitor) for (i)
    output fan @ rear top, and (ii) input fan @ front (don't get me started
    about HD cooling in the process).

    I'm just upgrading to this mobo and soon will get el4200 ram, and a 2.4C-~3C
    processor, and will probably want to see what it can do, in comparison to
    published results. Don't know what heat to expect.
     
    kgs, Jan 4, 2004
    #5
  6. kgs

    kgs Guest

    Theoretically you could get a seperate temperature sensor to connect b/t the
    mobo and a placement in the hottest part of the psu (the highest number is
    probably the one you want). This value may enter the ASUS equation.

    But in order to respond to the mobo/cpu/psu temp readings by controlling the
    CHA, PWR, and OTHER.... fans, (apparently the cpu fans are monitored and
    adjusted based on the equation), you need to disconnect the fans from the
    the mobo. If you disconnect them then you have no assurance then are
    running, and you don't know their speed. If they were plugged into the
    mobo, and the speed monitoring option was on, an alarm beeps, and flashes,
    and you see speed 0, where normally you would be ok.
     
    kgs, Jan 4, 2004
    #6
  7. kgs

    kgs Guest

    Unless you can control the speed inline (how about one of the many
    faceplates). Can you then still have your speed read monitored by
    bios/software, and have your alarm if threshold rotaion monitored this way?

    At this point I'm going to need 476 componentsm, in place of an answer.
     
    kgs, Jan 4, 2004
    #7
  8. kgs

    kgs Guest

    These things come with temp sensors for each of, say, 4 fan speed control
    knobs. Sometimes the temp sensor is in the fan itself. Don't know if it
    must be for this to work. Could you get a unit with individual temp sensors
    that are not part of the fan, and could I use one of these to connect to
    psu. This would't be advantageous in the equation, but at least I'd know
    the temp. And I could get a bunch of other fans and put them all over the
    pc. My psu has over temp and over power safeguards. Good thing b/c I
    wouldn't know how hot to set my sensor before it e-mails the CIA.

    BTW, if using a dual channel kit of EL4200 RAM with an ASUS P4C800-E
    deluxe, and using the (not add~$300.00) 2.4C/2.6C/2.8C/3.0C cpu, for example
    @1:1 @~280/560/1160FSB @3-3-4-7 @2.85V (w/ appropraite voltages and timings
    supplied by anandtech.com) considered the best, as many sites say it is, is
    this not considered overclocking, if it is indeed the best (don't try to get
    better), and does that not indicate that it is going to get hot, to the
    point that I may be prepared to need extra cooling.

    Another site with similar results w/ma obo and ram, which may be better for
    me, for cooling, for a change are at ...

    fyi, I needed to find out about these fan thingies anyways.
     
    kgs, Jan 4, 2004
    #8
  9. kgs

    kgs Guest

    winbond.com, no legitreviews.com

    I have read all the reviews, and I'm gonna copy-cat as much as possible,
    because there is a known means to an end. I will be preparing to tackle
    any cooling issues if req'd at any time. I have 2 questions: (1)How much do
    I
    need for my specific purpose, and if you can (2), should I get the
    specific processor.

    I am upgrading because here in Toronto, using Rogers hi-speed cable
    internet, I have recently discovered the newsgroups. These contain upwards
    of 10, 000, 30,000, 100,000 messages in each group. I get a six pack
    dispered throughout about eleven groups each day. I mark for download, and
    then finally
    combine and decode them, currently using OE. My old 192 MB, cusl2-c w/
    eleron600(I know ) just crashes, hangs, waits, etc.. to excess.

    Q1

    How much EL4200 does a serious homegrown OE nntp user need: (2x256), or
    (2x512)? I don't have the chance to play around. I can only do things once
    at a time.

    I am upgrading to an ASUS P4C800E-deluxe. I plan on also getting the 2.6C
    box cpu, because it seems like a sweet spot, and is not the baby in the C
    series. I assume the 2.4, 2.6, 2.8, and 3.0 behave the same. From reviews

    I assume the 3.2 behaves somewhat differently, maybe more ocable. It is
    also

    lot more money. If recommended I could also get the 2.4C(~$???),
    2.8C(add~$50), or 3.0C(unlikely)(add ~$150). I just tried to fill in this
    2.4C(~$???) value above from a www site to get my facts all in a row, and
    found the 2.4 and 2.6 similarly priced. I have read a couple times in
    reviews that the 2.4C has been used and they said it was used because it
    was very overclockable. I assumed this would be true similarly about any of
    the C b/t 2.4C-3.0C. I also assumed the articles I was reading may be older,
    and that the 2.4C was probably the sweet spot when the article was written,
    and they would have achieved similar(and therefore better) with a 2.6C.

    Q2

    Any comments on the 2.4C vs 2.6C question.



    don't worry, the best is yet to come, wait for ALL-IN Wonder post.
     
    kgs, Jan 4, 2004
    #9
  10. kgs

    kgs Guest

    kgs, Jan 4, 2004
    #10
  11. kgs

    Mistoffolees Guest

    Let's slow down for a moment. We are getting into the minutiae but
    not resolving some important questions. These include issues such
    as the utilization of the P4C800-E motherboard, e.g., business,
    home, gaming, etc.? Or the price category that is wanted, e.g., low
    middle or high end? Other interesting points include what operating
    system, e.g., Win9X vs. Windows 2000 vs. Windows XP or Linux? And
    what is the local environment --- Central Australia, Alaska, if
    you get the point.

    OK. Answer these first for it will ultimately determine the type
    of P4 CPU that will be needed, amount of RAM, other peripherals,
    etc., all of which will have a bearing on PSU, cooling needs, case,
    etc. To have an optimal system, all of these need to be factored.
    Enabling or disabing Q-fan is one of the most minor questions that
    is involved in assembling a P4C800-E. And whether or not the case
    fans (i.e., non-CPU) are 2-wired or 3-wired is inconsequential if
    one is not concerned about their rotation speeds. The important
    point is to have an computer running as optimally as what can be
    reasonably achieved.

    And as for CPU fans, there are 3 variations: (a) Fixed speed, as
    typical of most, but can be varied by the motherboard under Q-Fan;
    (b) Variable speed, usually with its own thermal sensor, as with
    the Intel HSF's provided with the retail, or "boxed", CPU's; and
    (c) Variable speed controlled by external thermal sensor *or*
    potentiometer, e.g., ThermalTake Xaser.
     
    Mistoffolees, Jan 4, 2004
    #11
  12. kgs

    kgs Guest

    ya, and, and what does Q-fan do, to what, and why. Hardware usage in this
    respect is based on hardware usage. Monitoring is monitoring. Varying is
    varying. What varies. What is variable. What monitors. What is
    monitorable. One thing may need varying while the other product does not.
    I have not see any mention of dB meteres in cases. MAybe there should b.
    What varies, and monitors when otherwise it may not be monitorable, or
    variable. So see my question(s).

    I am ignorant.
    Ovrclocking makes heat.
    You cannot overclock higher than using an ASUS P4C800-E with EL4200 Dual
    channel RAM. I would love you too show me how to OC higher, and then I
    would ask you again, does c make heat. Is OC'ing the reason you want to
    controll heat, above what stock cooling is supplied, or not supplied.
    The 2.4C to 30C are cousins. They overclock and behave similarly. I know
    exactly what V and timings are possible to achieve max OC'ing.
    The 3.2C is a different chip architecture, and behaves and OC's differently.
    It is more OC'able, GHz for GHz
    You must not have too much heat.
    Components all work differently, including the integration of a decent fan.
    Noise is bad.
    Big or small I can connect them all.


    I agree with you.
    I cannot tell you exactly what I will be doing all the time.
    So I don't exactly know how much cooling I'm gonna need. But I'm gonna be
    hot either way. Guaranteed.
    I'll go into the system later.
    Duty-cycle and Q-fan are all I'm trying to work through. The selection of
    fan may allow or not allow the system to work as a whole. It may or may not
    work. The selection of cooling components will have a great effect on what
    I assume is a good idea. Just gotta find out what the idea is.
    Assume I have the ability to OC as much as anybody, and play a reallty
    intense game as much as anybody, and I have determined the right connections
    of all my hardware. Then the most efficient fans which run for the least
    amount of time, at the lowest noise level, and can handle any heat I can
    throw at it, with the least amout of human input, is the best. What, what?

    I'll get to the more serious problems when I build the all in wonder post.
     
    kgs, Jan 5, 2004
    #12
  13. kgs

    kgs Guest

    If you buy a 550W psu and only need 230W (as ASUS recommends for an average
    system on p.2-28 of the manual) you are generating a lot more heat than you
    need. But if the "duty-cycle" is much better, you may actually develop less
    heat.
     
    kgs, Jan 5, 2004
    #13
  14. kgs

    kgs Guest

    Shazam.
    pc ics, superi/os OR
    http://www.winbond-usa.com/products/winbond_products/pdfs/PCIC/627hf.pdf
    pp39-70...

    It looks like 3 fans can be turned on or off and the speed can be varied
    according to various temp ranges.

    So it looks like I'll need a 3-pin with tach output that is variably speed
    controllable. Do I need a therm.... equipt fan mister?

    I'd like an efficient one that is quiet, and conforms to the fan specs on
    p2-27 of the manual (avail at asus.com). Possibly in red colour , not
    UV, or LED. To match the SATA, and soon to be IDE and FLOPPY round red.

    the "3-pin CPU_FAN, PWR_FAN, CHA_FAN fan
    connectors support cooling fans of 350mA~740mA (8.88Wmax.) or a total of
    1A~2.22A (26.64W max.) at +12V". I don't know if is the variable
    output(controllable range), or if any value in between is the max fan rating
    to connect
     
    kgs, Jan 5, 2004
    #14
  15. kgs

    kgs Guest

    Shazam.
    pc ics, superi/os OR
    http://www.winbond-usa.com/products/winbond_products/pdfs/PCIC/627hf.pdf
    pp39-70...

    It looks like 3 fans can be turned on or off and the speed can be varied
    according to various temp ranges.

    So it looks like I'll need a 3-pin with tach output that is variably speed
    controllable. Do I need a therm.... equipt fan mister?

    I'd like an efficient one that is quiet, and conforms to the fan specs on
    p2-27 of the manual (avail at asus.com). Possibly in red colour , not
    UV, or LED. To match the SATA, and soon to be IDE and FLOPPY round red.

    the "3-pin CPU_FAN, PWR_FAN, CHA_FAN fan
    connectors support cooling fans of 350mA~740mA (8.88Wmax.) or a total of
    1A~2.22A (26.64W max.) at +12V". I don't know if is the variable
    output(controllable range), or if any value in between is the max fan rating
    to connect
     
    kgs, Jan 5, 2004
    #15
  16. kgs

    kgs Guest

    Shazam.
    pc ics, superi/os OR
    http://www.winbond-usa.com/products/winbond_products/pdfs/PCIC/627hf.pdf
    pp39-70...

    It looks like 3 fans can be turned on or off and the speed can be varied
    according to various temp ranges.

    So it looks like I'll need a 3-pin with tach output that is variably speed
    controllable. Do I need a therm.... equipt fan mister?

    I'd like an efficient one that is quiet, and conforms to the fan specs on
    p2-27 of the manual (avail at asus.com). Possibly in red colour , not
    UV, or LED. To match the SATA, and soon to be IDE and FLOPPY round red.

    the "3-pin CPU_FAN, PWR_FAN, CHA_FAN fan
    connectors support cooling fans of 350mA~740mA (8.88Wmax.) or a total of
    1A~2.22A (26.64W max.) at +12V". I don't know if is the variable
    output(controllable range), or if any value in between is the max fan rating
    to connect
     
    kgs, Jan 5, 2004
    #16
  17. kgs

    GHalleck Guest

    Go buy a Dell or a Compaq or a HP. Their engineers would have already
    done all of the calculations and the worrying for you. :))
     
    GHalleck, Jan 5, 2004
    #17
  18. kgs

    Paul Guest

    I agree with Mistoffolees, you have to slow down a bit. The idea is, you
    post an article on USENET with a descriptive title, and then you wait for
    an answer or answers to appear. If the person responding to you asks for
    more information, then a reply with the information is useful.

    By placing many interesting and diverse questions in 12 posts, I am overwhelmed
    and cannot respond to each and every post. It would take me all day to
    write twelve detailed replies etc. I hope you were not expecting a reply to
    each of those posts to be drafted. What takes you five minutes to ask,
    takes me an hour to answer.

    Sometimes it is useful to start separate threads for unrelated questions,
    but even then, you could be in for some flameage if you place a whole bunch
    of questions in a group in close time proximity to one another. The group
    expects you to do some research on your own, so that your questions can
    be focused on the things you are uncertain about, as opposed to writing
    a very broad answer covering every possible combination of hardware.

    On the one hand, I hate to be a "net nazi", but on the other hand I want
    you to understand how best to get the information you need, by not alienating
    the people who can potentially answer your questions. (I only mention this
    because you said you weren't happy that people hadn't responded to your
    other posts...)

    Also, this is a non-binary group, which means that attaching JPEG files would
    normally be frowned on. Some people effectively have to pay per byte of
    download, and a large binary in an otherwise text-only group is an expensive
    and unwelcome surprise (people in Europe pay for local phone service by
    the minute, so they are paying for your 1MB scan of the PSU as we speak).
    The people in sci.electronics use some alt.binaries group for their
    schematics and the like, but I don't remember right off hand which one
    they use.

    Back to your questions:
    Fan speed monitoring means they will offer you the tachometer signal coming
    from the power supply fan. Examine your power supply carefully and you will
    find a two wire cable with a three pin style connector on the end. The
    two wires carry the tachometer signal and a ground signal. If this three
    pin connector is connected to a motherboard three pin fan header, then
    the monitor chip can count fan revolutions and make them available while
    Windows is running, via Motherboard Monitor (MBM) or Asus Probe.

    Another option some power supplies offer, is PSU temperature sensing. If
    you have a power supply with this feature, you will find a two wire cable
    with a two pin connector. This connects to a two pin header on the motherboard
    with a name like TRPWR or the like. Inside the PSU will be a thermistor
    (a NTC negative temperature coefficient resistor) whose resistance changes
    with temperature. At 25C, this thermistor will have a resistance of 10K ohms
    (at least that is the defacto standard), so an Asus TRPWR header will give
    reasonably accurate readings near 25C. (Note: Do not attempt to add a
    thermistor to the PSU yourself - there are lethal DC voltages in there
    and you never know whether the bleeder resistors on the big electrolytic
    capacitors are doing their jobs or not. And draining the caps by placing
    a screwdriver blade across the two electrodes on a cap can deafen you!)
    The waste heat from a power supply is for the most part a linear function
    of the output current. Say the motherboard is drawing 100 watts from the
    power supply, and the power supply has a stated efficiency of 80%. This
    means it draws (1/0.80)*100W = 125W from the wall, and 25W is discarded
    as heat. If you are drawing 230W at the output, then the waste heat is
    57.5W. If a 350W and a 550W supply have the same 80% efficiency rating,
    and each is asked to deliver 230W, they both waste 57.5W in the form of
    heat. To reduce heat, find the most efficient supply you can. Computer
    PSUs are not very efficient, and finding even an 80% efficient computer
    PSU is difficult. Check the specs on Fortron supplies and compare them
    to some of the others.
    First of all, to monitor fan speed you need the tachometer signal.
    If three wires come from the fan body, then the tach signal exists.

    Fans which draw large currents from +12V or fans equipped with a
    variable or switchable resistor to vary fan speed, tend to have a
    four pin (disk drive style) Molex connector to provide the power.
    When you buy a fan with this option, there may be a single wire
    with a three pin connector on the end. The single wire carries the
    tachometer signal, and when the three pin connector is connected
    to a three pin header on the motherboard, you can monitor the
    fan speed. Then, an alarm function will work properly.
    If the motherboard supports a fan control option, it will quite likely
    be called Q-fan by Asus. Since the CPU fan is associated with whatever
    device is used to monitor the CPU temperature, it makes sense that only
    the CPU fan is controllable. The other fans are generally not controlled
    by the motherboard. You can control other fans in your computer with
    third party drive bay controller boxes (Thermaltake Nexus?), but at
    least some of these cheap controllers use a simple variable resistor
    and the design quality is terrible (high failure rate).

    For chassis fans, I would recommend you read as many specs as you can,
    especially on sites like http://www.quietpc.ca/casefans.html or the like.
    Sleeve bearing fans are quieter than ball bearing fans, but on the
    cheap ones, the bearings become noisy/dry out in a matter of days. An
    exception might be the Panasonic Panaflo sleeve bearing fans. A large,
    low RPM fan is quieter than a small high RPM fan. Many cases have
    space for a 80mm fan and that makes a good choice for a chassis fan.
    (Since you are in Canada, take a look at bigfootcomputers.com for
    Panaflo fans. Use the search engine and search on Panaflo for a list
    of what is available.)

    Acoustic sound insulation material placed inside the case is generally
    not a good idea, if you believe the people who report a significant
    temperature rise after the padding is added inside the case.

    To start with, don't go overboard with fans. I recommend one fan in the
    back of the case plus the fan in the PSU as a minimum. Add the fan to
    the front of the case if you find the motherboard temperature is
    climbing too much. People who have eight fans in their case probably
    don't need all of them in order to ensure their electronics have a long
    life.

    Hard drive temperature is important, but in combination with the room
    humidity level. If your computer is in an air conditioned room, there
    is little to worry about, as the humidity will be 40% or so. If the
    computer is going to be in an un air conditioned space, then you should
    think a little about drive cooling. Buying a low power drive is a good
    start - check http://storagereview.com/comparison.html and see their
    "net drive temperature" chart for some good choices in low delta T
    drives.

    For your CPU fan, you can use the Intel HSF that comes with the retail
    CPU. This is a quality product with a reasonable fan for the job. Since
    the fan has a built in thermal control function, you can rely on it alone
    or you can use Q-fan as well. Some experimenting will be needed to see
    what combination of controls gives you consistent CPU temperatures.

    A Zalman CNPS7000 HSF is the current champion in terms of quiet and cool,
    but check the engineering information on the page carefully, such as
    dimensions and the like, because this thing is big and heavy.
    bigfootcomputers.com has these, as does bytewizecomputers.com .
    Replacing the Intel HSF with one of these will at least make the CPU
    cooling inaudible.

    http://www.zalman.co.kr/english/product/cnps7000a-alcu.htm

    That should give you some ideas to get started. Note that when battling
    noise, that once one source is made quiet, another part will become audible.
    The computer can never be too quiet. You could always do what the guys
    with the Delta 6800 RPM fans do, and turn up the stereo.

    HTH,
    Paul
     
    Paul, Jan 5, 2004
    #18
  19. only to be over-ruled by the accountants and marketing...
     
    dazed-and-confused, Jan 5, 2004
    #19
  20. kgs

    kgs Guest

    Thank you. I am keeping vey busy. I am trying to learn as much as
    possible.. I just considered going throuth the asus manual front to back for
    the third time and asking a question, or making a statement about everything
    in it that applies to me, or may apply in the future.

    My question was originally is Pc Probe/Q-fan/BIOS and my P4C800-E deluxe
    mobo going to require a fan of a certain type and why, because I need a new
    one and like being prepared. I was probably going to go to bigfoot for my
    very next purchases anyways. I will do as you say. But if I ask any more,
    such as anything, the majority of which I have already asked, I am sure not
    to get a staight answer. Granted I may jump the gun, and it wil take me
    several readings before I get everything understood. Non-intentionally, the
    effect of my posts is that I plow through to the most probable solution. I
    do not think I support mis-information or extraneous matter. I don't care
    to explain. I'll be back and would be happy to hear from anybody. And I
    hope others are learning from my journey.
     
    kgs, Jan 6, 2004
    #20
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