noisy fan

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badgolferman

I have just upgraded my computer from a 800 MHz AMD Duron to a 2.0 GHz
Intel based motherboard. The computer is very noisy where it has a
sort of whine coming from the CPU fan. At least that is the only way I
can quiet it is to stop the fan momentarily.

I have replaced the stock Intel fan with a heavy brass heat sink/fan
combination from Thermaltake (sp?) and it varied the whine pitch
slightly. I have tried wiggling and pushing the motherboard and
internal components to find signs of vibration. I have also covered up
external air holes to see if a whistling action is being created. I
have put a pieces of felt beneath it to dampen any floor vibrations.
The computer sits on hardwood floor and has plenty of ventilation.

Nothing seems to stand out for the cause of the whining sound. Can
anyone give me any other ideas? Thanks.
 
hi

best have a look at quietpc.com - they are really helpful with noise
problems. sadly, most standard fans are noisier than anyone really wants
these days, but it's the price to pay for the processing we get nowadays!

i wouldn't stop the fan too often on the cpu - might get expensive!!!!!

cheers

fiev
 
I have just upgraded my computer from a 800 MHz AMD Duron to a 2.0 GHz
Intel based motherboard. The computer is very noisy where it has a
sort of whine coming from the CPU fan. At least that is the only way I
can quiet it is to stop the fan momentarily.

I have replaced the stock Intel fan with a heavy brass heat sink/fan
combination from Thermaltake (sp?) and it varied the whine pitch
slightly. I have tried wiggling and pushing the motherboard and
internal components to find signs of vibration. I have also covered up
external air holes to see if a whistling action is being created. I
have put a pieces of felt beneath it to dampen any floor vibrations.
The computer sits on hardwood floor and has plenty of ventilation.

Nothing seems to stand out for the cause of the whining sound. Can
anyone give me any other ideas? Thanks.
Click to expand...


If the whining subsided when you stopped the fan it seems
pretty clear what made the noise... that your new fan makes
similar noise might be just bad luck? Generally a
ball-bearing fan will always have a certain degree of
'whine' though much less so when at low RPM. Thus you have
to decide if you want the (typical) longer lifespan and
reliability of a ball-bearing fan or can accept the tradeoff
of shorter life for a sleeve-bearing fan (or pay premium
prices for the good sleeve bearing fans like Panaflo or
Papst). Ideally a Panaflo 25mm thick by whatever diameter
is called for on your new heatsink, would be the best
option. They speed-grade them too so you'd want an "L" (for
"low") in the model name, not "M" or "H", etc.

So for example if you need an 80mm fan, the part # would be
FBA08A12L
or for a 92mm,
FBA09A12L

Note that some don't have the appropriate motherboard fan
header connector, it is an option that must be mentioned by
seller. Also there are other potential sources of whining
noise like motherboard inductors (typically look like
doughnut-shaped painted *magnets* (actually just ferrite)
wrapped in thick wire), which might quiet down if you firmly
grasp it between both fingers (as only a test to isolate the
noise).
 
kony said:
If the whining subsided when you stopped the fan it seems
pretty clear what made the noise... that your new fan makes
similar noise might be just bad luck? Generally a
ball-bearing fan will always have a certain degree of
'whine' though much less so when at low RPM. Thus you have
to decide if you want the (typical) longer lifespan and
reliability of a ball-bearing fan or can accept the tradeoff
of shorter life for a sleeve-bearing fan (or pay premium
prices for the good sleeve bearing fans like Panaflo or
Papst). Ideally a Panaflo 25mm thick by whatever diameter
is called for on your new heatsink, would be the best
option. They speed-grade them too so you'd want an "L" (for
"low") in the model name, not "M" or "H", etc.

So for example if you need an 80mm fan, the part # would be
FBA08A12L
or for a 92mm,
FBA09A12L

Note that some don't have the appropriate motherboard fan
header connector, it is an option that must be mentioned by
seller. Also there are other potential sources of whining
noise like motherboard inductors (typically look like
doughnut-shaped painted magnets (actually just ferrite)
wrapped in thick wire), which might quiet down if you firmly
grasp it between both fingers (as only a test to isolate the
noise).
Click to expand...

I have a Socket 478 Biostar motherboard. Are you saying a sleeve type
fan is quieter than a ball-bearing type? I'm sure the Thermaltake is a
ball-bearing. The stock Intel one I don't know about.

It seems the fan always runs at the same speed. I looked in the BIOS
for some sort of control but didn't notice anything obvious. The
motherboard didn't come with a manual but I downloaded one and will
look later.
 
Get a better, or at least a quieter fan. Make sure that the fan you are
using is not defective, if you decide to put up with it.

--

JANA
_____


I have just upgraded my computer from a 800 MHz AMD Duron to a 2.0 GHz
Intel based motherboard. The computer is very noisy where it has a
sort of whine coming from the CPU fan. At least that is the only way I
can quiet it is to stop the fan momentarily.

I have replaced the stock Intel fan with a heavy brass heat sink/fan
combination from Thermaltake (sp?) and it varied the whine pitch
slightly. I have tried wiggling and pushing the motherboard and
internal components to find signs of vibration. I have also covered up
external air holes to see if a whistling action is being created. I
have put a pieces of felt beneath it to dampen any floor vibrations.
The computer sits on hardwood floor and has plenty of ventilation.

Nothing seems to stand out for the cause of the whining sound. Can
anyone give me any other ideas? Thanks.
 
I have a Socket 478 Biostar motherboard. Are you saying a sleeve type
fan is quieter than a ball-bearing type? I'm sure the Thermaltake is a
ball-bearing. The stock Intel one I don't know about.
Click to expand...

The stock fans are usually ball-bearing too. Sleeve bearing
fans certainly make noise still but not that high-pitched
whine (usually, sometimes a motherboard fan controller can
cause it too but not so often). The sleeve-bearing itself
is relatively quiet and the noise tends to be only in the
lower frequencies. If you just randomly chose a
sleeve-bearing fan you could expect it to have a much
shorter lifespan, particularly in an environment where
there's heat like atop a heatsink.
It seems the fan always runs at the same speed. I looked in the BIOS
for some sort of control but didn't notice anything obvious. The
motherboard didn't come with a manual but I downloaded one and will
look later.
Click to expand...

Could be that it does always run at same speed, for most of
PC history that's how it's been and can be a fine solution,
providing that single speed is optimized towards good life
and low noise... basically what helps there is the better
metal portion of the heatsink such that it takes less
airflow to remove heat, reducing need for a loud(er)
high-flow fan.
 
kony said:
The stock fans are usually ball-bearing too. Sleeve bearing
fans certainly make noise still but not that high-pitched
whine (usually, sometimes a motherboard fan controller can
cause it too but not so often). The sleeve-bearing itself
is relatively quiet and the noise tends to be only in the
lower frequencies. If you just randomly chose a
sleeve-bearing fan you could expect it to have a much
shorter lifespan, particularly in an environment where
there's heat like atop a heatsink.
Click to expand...

Okay, I have access to three different P4 fans. The stock Intel
aluminum heat sink and fan combo (originally installed), a Thermaltake
1U low-profile brass heat sink P/N A1240 (currently installed), and an
Intel 1U low-profile brass heat sink. Which would you recommend?
 
Okay, I have access to three different P4 fans. The stock Intel
aluminum heat sink and fan combo (originally installed), a Thermaltake
1U low-profile brass heat sink P/N A1240 (currently installed), and an
Intel 1U low-profile brass heat sink. Which would you recommend?
Click to expand...

Nothing geared towards "low profile". Fan thickness
directly effects both the RPM needed to push a given amount
of air through an impedance (the 'sink fins) even moreso
than in free-air use as rated by manufacturer specs, - AND-
there is a certain minimal thickness necessary to allow for
a better bearing design which will tend to be quieter and
far longer lasting. That thickness can vary and is
generally a minimum of 12mm but most often 15-20mm.

This doesn't mean merely grabbing a 15+mm fan is sufficient
though, only that among other variables (like the particular
make and model/family of fan) it's also an important
consideration. It may well be that none of the fans you
have are good for low noise, minimal "whine". Sadly major
manufacturers of heatsinks seem to care almost nothing about
noise levels, always opting for higher flow fan.

The ideal fan will be (as mentioned previously) the correct
diameter for mounting on the 'sink. It'll be at least
(usually) 25mm thick (unless for some reason you simply
can't find screws to accomodate fans of different thickness
than the original). It will have low RPM, preferibly under
2500 RPM and perhaps as much lower than that as possible,
depending on the case airflow and room ambient temps too,
which will vary the flow rate needed per application/system.
<2500 RPM typically corresponds to a fan having a current
rating of under .15A, closer to .10A, if you can't find
specs on specific fans, though most good fans have
manufacturer spec sheets available. Even on an intel fan
that's proprietary, it will be essentially a stock fan with
minor differences like rotation direction, frame shape, such
that the manufacturer's spec sheet for same diameter,
thickness, and amperage fan will be close enough to
consider.

If you "must" use one of the fans you have, it's easy enough
to just plug each in, in turn, and compare the noise. If
you had a spare 2W ~ 47-68 Ohm power resistor you could add
that inline to drop power to the fan and further reduce it's
RPM, a cheap and reliable method in lieu of a more expensive
and large "PC fan controller" product.
 
badgolferman said:
Nothing seems to stand out for the cause of the whining sound. Can
anyone give me any other ideas?
Click to expand...

Thaks to those who helped diagnose the whining sound. I picked up
another Intel stock heatsink/fan and it is quiet with no whine. It's a
good thing I was able to pick these up for virually no cost.
 
Thaks to those who helped diagnose the whining sound. I picked up
another Intel stock heatsink/fan and it is quiet with no whine. It's a
good thing I was able to pick these up for virually no cost.
Click to expand...


Unfortunately many of them start out quiet but then develop
the whine over the course of months... has been like this
for years, their heatsink/fans have been quite a
disappointment considering the prices of some of the CPUs
they came with.
 
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