Noisy CPU fan

Hi,

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 wrote:
Hi,

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 ?



http://www.silentpcreview.com/

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.

HTH,

BC

goo_lu1 wrote:
Hi,

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 ?


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. (www.thermalright.com/product_default.htm)

JD 寫�：


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

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.

Here is an example of a heat-sink when used with an 120mm fan is near
silent, Thermalright XP-120. (www.thermalright.com/product_default.htm)

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

BC wrote:

snipped

http://www.silentpcreview.com/

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.

HTH,

BC


Have you seen the size of the heatsinks used in the Mac's or
any other computer which utilizes low-RPM fans?

goo_lu1 wrote:
JD 寫�：



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


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.

Here is an example of a heat-sink when used with an 120mm fan is near
silent, Thermalright XP-120. (www.thermalright.com/product_default.htm)



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.

On 16 Jan 2006 11:47:35 -0800, "goo_lu1"
wrote:

Hi,

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 ?

- 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
controller.

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.

JD wrote:
goo_lu1 wrote:
Hi,

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 ?


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.
(www.thermalright.com/product_default.htm)

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

Speak the truth and leave shortly there after.

"goo_lu1" wrote in message
ups.com...

JD ??:


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

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.

Here is an example of a heat-sink when used with an 120mm fan is near
silent, Thermalright XP-120. (www.thermalright.com/product_default.htm)

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.