Noisy CPU fan

Discussion in 'Computer Information' started by goo_lu1, Jan 16, 2006.

  1. goo_lu1

    goo_lu1 Guest


    I find my PCs (no matter PII, P4) produce big noise after power up and
    most of the noise being produced by CPU fan. I haven't tried
    overclocking in any of these PCs and I even open the case to improve
    ventilation but with no improvement. I would like to know how can I
    reduce that noise due to CPU fan ?
    goo_lu1, Jan 16, 2006
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  2. goo_lu1

    BC Guest

    Good web site with all sorts of hints, tips, and techniques for quieting
    a PC.

    P4's tend to be noisy, in my experience. Athlon 64 CPU with Cool &
    Quiet: very nice.

    Several cases are known to reduce noise some.

    In my office, I use a Mac Mini: silent. I believe that iMacs and Apple
    G5s are designed to run very quietly--all the G5s I have observed
    running have been silent--fans blow at a very leisurely pace.


    BC, Jan 16, 2006
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  3. goo_lu1

    JD Guest

    I assume from your post that it is intel CPU's you are using which are
    notorious for producing a lot of heat.
    you should replace your "reference" heat sink and fan (HSF) for a more
    efficient one, there are also other quieter and more expensive options
    like water cooling, refrigeration units.

    Here is an example of a heat-sink when used with an 120mm fan is near
    silent, Thermalright XP-120. (
    JD, Jan 16, 2006
  4. goo_lu1

    goo_lu1 Guest

    JD 寫é“:

    But PCs in my office are not that noisy. They all use PII, PIII or P4
    CPU and because of business use, they will only use common H/W like
    IBM, HP, etc. I don't believe good heat sink will be used. However, I
    find nearly no noise at all even I sit just beside my office PCs. I
    don't know why my DIY PC will generate such intolerable noise.
    goo_lu1, Jan 16, 2006
  5. goo_lu1

    goo_lu1 Guest

    I faced such noise problem since I built my first Pentium PC. I don't
    think changing to Mac is a solution for me.
    goo_lu1, Jan 16, 2006
  6. goo_lu1

    Mistoffolees Guest

    BC wrote:

    Have you seen the size of the heatsinks used in the Mac's or
    any other computer which utilizes low-RPM fans?
    Mistoffolees, Jan 16, 2006
  7. goo_lu1

    JD Guest

    It could simply be the case you have used is flimsy and the vibrations
    from the cpu, hard drive and optical drives are magnified by this, also
    check that your cabling is not touching the fan.
    JD, Jan 16, 2006
  8. goo_lu1

    kony Guest

    - Run a continuous full-load test to determine the max temp
    seen with the present heatsink and ambient (room) temp.
    Prime95's Torture Test, Large In-Place FFTs setting is a
    fair attempt at that.

    - After it had been running at least 30 minutes, note the
    temp, and the fan speed and noise level. If the fan speed
    had not risen much or the CPU temp is not very high, your
    present 'sink has a bit of margin to cool the CPU adequately
    with a lower speed fan on it instead of the present fan

    - If it's a retail boxed 'sink that uses a proprietary fan,
    you have to either fabricate an alternate mouting method for
    a (presumably standard) alternate fan or replace entire
    'sink with one that accomodates a standard fan.

    - If the temp from Prime95 test was very high or the fan
    RPM went up significantly, beyond the prior level you had
    already considered too loud, it will most likely be
    necessary to replace entire heatsink (assuming present 'sink
    is mounted properly and present chassis cooling is
    sufficient, leaving the efficiency of the heatsink base
    itself as the remaining variable).

    - Choose a large diameter, minimum 80mm, x 25mm thick fan.
    Compare the original fan current rating or RPM spec to find
    a fan with a little lower rating, or perhaps a lot lower
    rating if your replacement heatsink is good enough to allow
    it, retain low temps. Generally speaking, the upper limit
    on the fan should be about 3000 RPM, 0.15A or so as a median
    value, perhaps slightly higher for use on a board with
    fan-throttling circuit to control it but not much higher,
    and even lower, about 0.12A or 2400 RPM without such a fan

    Ultimately fan speed depends on CPU heat production too.
    The P4 will need above range most likely but if you found a
    sufficiently large heatsink and fan for the P2, it might
    allow running a fan far slower, even under 1000 RPM. PII
    often don't have heatsinks to accomodate such fans though so
    it may take a great deal of searching to find one or
    devising an alternate mounting method, perhaps metal straps
    and bolts by drilling small holes in heatsink fins to mount
    them, or nylon wire-ties, or another method depending on the
    specifics of the sink(s) available. The main thing to avoid
    is a small diameter and thin fan, to not use a 50 mm x 10 mm
    thick fan as was all too common on generic PII 'sinks. Such
    a small fan would have to run at much higher RPM.
    kony, Jan 16, 2006
  9. goo_lu1

    sbb78247 Guest

    It is a nice unit, but with the originally spec panaflow 120x38 it is on the
    loud side. (just took one out). With a 120x25 it would probably be
    quieter, but it would seem you give up air flow for db.
    sbb78247, Jan 16, 2006
  10. JD ??:

    But PCs in my office are not that noisy. They all use PII, PIII or P4
    CPU and because of business use, they will only use common H/W like
    IBM, HP, etc. I don't believe good heat sink will be used. However, I
    find nearly no noise at all even I sit just beside my office PCs. I
    don't know why my DIY PC will generate such intolerable noise.
    We use Dells' here at work. When the PC is initially powered on, there is
    no CPU fan noise, actually during most of the workday the CPU fan is silent.
    It is only when I stress the CPU by compiling an application that I hear the
    CPU fan speed up and it is very noticable. The CPU fan speed will usually
    drop back down after the compile has finished.

    On your own DIY PC, is the CPU fan always running at full speed? What about
    the noise from the case fans? You haven't described this "noise". Is it
    noisy because the fan's bearings have lost their lubrication? Is the noise
    coming from the power supply fans?

    If you built your DIY PC without regard for low noise, then you'll usually
    end up with a noisy DIY PC. If you would have built it with a low noise
    power supply, and low noise case fans and low noise CPU fan then you'll end
    up with a quiet PC. Also current high end video cards seem to have very
    noisy fans.
    Homer J. Simpson, Jan 16, 2006
  11. goo_lu1 Guest

    Those HP, IBM usually use a very large heatsink without fan on heatsink.

    JD ??:

    But PCs in my office are not that noisy. They all use PII, PIII or P4
    CPU and because of business use, they will only use common H/W like
    IBM, HP, etc. I don't believe good heat sink will be used. However, I
    find nearly no noise at all even I sit just beside my office PCs. I
    don't know why my DIY PC will generate such intolerable noise.
, Jan 17, 2006
  12. goo_lu1

    goo_lu1 Guest

    JD 寫é“:
    The cases are all metallic (in fact heavy in my point of view) so it's
    not flimsy. Also, I didn't notice observable vibration from CPU, HD or
    optical drives. No touch between cable & fan, no doubt.
    goo_lu1, Jan 17, 2006
  13. goo_lu1

    goo_lu1 Guest

    Homer J. Simpson 寫é“:
    The noise came out from the moment I powered on the PC till it's shut
    down, no matter I ran any application or just left it alone.
    In some of the DIY PCs, I hadn't installed any case fan but I removed
    the case cover plates to help ventilation.
    Lost lubrication ? How to check ? I used CPU fan came with the CPU
    No, because I had tried turning on power supply fan alone and I didn't
    heard that noise. Actually, after you opened the cases, you will easily
    found out the noise source. I'm sure it's the CPU fan (sometimes
    display card fan can add to the noise).
    Where to find low noise CPU fans ? How they distinguish from fans
    packaged with CPU modules ?
    That's my case with some DIY PCs. Yet, just now I'm building a P4 PC
    (478 socket) w/ ATI Radeon VE Dual Display card which has no fan
    attached (no case fan). I could clearly hear noise generated from CPU
    fan as I powere up the motherboard.
    goo_lu1, Jan 17, 2006
  14. goo_lu1

    goo_lu1 Guest 寫é“:
    Will heatsink caused noise generated from CPU fan went away ? Will CPU
    got heat to make big noise from the moment it powered up ? In my DIY
    PC, the PC noise was heard and stayed at similar level from the moment
    I pressed on power on switch. Actually in my years of work I never
    encounter a office use PC with that noise in my DIY PCs & the brand
    names not limited to HP, IBM, but also Acer, Compaq, etc.
    goo_lu1, Jan 17, 2006
  15. goo_lu1

    Plato Guest

    I've seen those. I've also seen Dells with large heatsinks that come
    with hood over the cpu/sink that runs to an external case fan.
    Plato, Jan 17, 2006
  16. goo_lu1

    jaykchan Guest

    I used to have this problem with a P4 from Dell. Turned out this was a
    common problem. I asked Dell to send me a replacement CPU/Case fan
    with the specific request that it had to be quiet. They refused to
    admit that some of their fans were noisy; but they sent me a quiet fan
    anyway. I needed to pay for it because the PC was out of warranty.
    Now, the PC is very quiet -- not quiet enough to leave it ON during the
    night near my bed, but is quiet enough that I don't know it is ON if I
    don't pay attention (and I am very sensitive to noise).

    If your PC or the CPU fan is still under warranty, you may want to ask
    the vendor for a replacement fan, and hope for the best. If it is out
    of warranty, you may need to order a quiet CPU fan from one of the
    sources that some newsgroup members have already suggested to you. You
    "may" also need to replace the heatsink with an oversized heatsink just
    in case the quiet CPU fan doesn't spin as fast as the noisy one.
    Better yet, order the quiet CPU fan and the oversized heatsink together
    in one unit; then you are sure that they match. You need to check the
    space around the CPU to make sure there is enough room for the
    oversized heatsink though.

    I don't think this is a good idea to run the PC with the case opened
    for a long time if you want to improve ventilation. Your PC doesn't
    sound like it is overheating, and opening the case may actually cause
    problem. The case is probably designed in a way that the case is
    supposed to be closed to channel the air through the various components
    inside the case in order to cool the components. If you open the case,
    the air flow may go all over the places in an undefined pattern. Some
    components may not get cooled properly. If you really want to open the
    case, you may want to point a household fan at the inside of the case.
    I am not an expert in this area. But this was what I was told when I
    was dealing with IBM XT back in 198x. A modern PC may not have this
    problem; but I always play safe and not leave the case opened for a
    long time especially in a hot summer.

    Hope this helps, and wish you a Happy New Year in advance.

    Jay Chan
    jaykchan, Jan 18, 2006
  17. goo_lu1

    goo_lu1 Guest

    For PII CPU, it's definitely out of warranty. The PC had one PII CPU w/
    its own fan (I think it's not likely to replace with a third party fan,
    right ?). No other fan used (graphic card has it's own heat sink and no
    fan, also no case fan used). No case fan used. This PII PC is noisy.
    I'm sure the PSU fan was not noisy.
    The motherboard used was intel which already has its on board heat
    sink. So I suspect further heat sink or case fan could help.
    You mean I need to replace the default intel PII CPU fan with one third
    party fan ? Any suggested model if so ?
    Yes, I don't think its overheating. Actually, I didn't open the case
    for my PII PC. I just did it on my Althon PC w/ WinFast S610 graphics
    card (which has it's own fan). Most of the noise came from that
    graphics card fan.

    With my new P4 PC, the noise mainly came from the CPU fan (original
    intel CPU fan) because that motherboard had on on board graphics port
    i.e. I didn't need to add any graphics card w/ any fan. But the noise
    from this PC was much lower compared w/ the Althon PC.
    goo_lu1, Jan 19, 2006
  18. goo_lu1

    jaykchan Guest

    I thought you were sure that the noise is coming from the CPU fan.
    After reading this, I have a feeling that you are actually not very
    sure. You may want to check if the noise is really coming from the CPU
    fan before adding/changing anything. You can check if the noise is
    coming from the power supply by simply use a stick to stop the fan in
    the power supply for a couple seconds to see if the noise is gone. If
    the noise is gone, this means the noise was coming from the fan inside
    the power supply. If the noise is still there, you may want to check
    if the noise is coming from the hard disk. You can do this by
    disconnecting the power cable from the hard disk and powering up the
    PC. If the noise is gone, this means the noise was coming from the
    hard disk. By doing this process of elimination, you can find out the
    source of the noise. Don't stop the CPU fan though; some CPU may not
    survive a short moment without cooling.
    I don't have any suggestion. You may want to ask around here, or check
    the web site that sells silent PC components.

    Good luck with your search.

    Jay Chan
    jaykchan, Jan 19, 2006
  19. goo_lu1

    Zaphod B Guest

    Here's a pretty good article with a couple of good solutions.


    Zaphod B

    "He grinned two manic grins, sauntered over to the bar
    and bought most of it."

    **The Restaurant at the End of the Universe**
    Zaphod B, Jan 19, 2006
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