Brent said:
Ok, my computers are LOUD. I hate fans because they make too much noise.
Right now I have two 80mm Sunon fans in each of my two computers, and I feel
like I'm sitting in the back of a 747 when they are both on. I'm thinking
about replacing them with one quiet 80mm fan. I'm also considering changing
the ATX power supplies to a quiet power supply.
It seems like most of the cooling news groups are full of *fan*atics, so all
I'm seeing are posts recommending at least 8 to 15 fans per box -- can we
get some honest opinions on whether or not a standard PC really needs all
this airflow?
No, it doesn't.
Will my machines *really* suffer from just one 80mm fan? I have standard
mid-tower cases... do I really need *two* 80mm fans?
One would be enough, depending on what criteria you use to determine 'enough'.
People seem to be terrified of 'heat' and have somehow gotten the idea that
everything should be as near room temperature as possible. Well, that might
be nice but there's the 80-20 rule, which states that the last 20% of
anything takes 80% of the time/cost/resources/what-ever-hurts. E.g. a 6C to
10C case rise can be had with reasonable airflow but it you want it down to
3C it's hurricane time.
You'd have to tell me where your two fans are located. Is that two rear
fans or one front and one rear? If it's the later, you can probably
eliminate the front fan with little impact, unless it's located in front of
the drives, in which case a low speed, and quiet, fan would do nicely
(although you could still probably eliminate it).
Odds are the rear fan is overpowered, if your complaint about noise isn't
exaggerated.
But it depends on the case layout and a host of other factors (like, is it
perforated with holes all over the place?). There isn't a 'simple'
solution. Well, except for the "hoot, man, throw another fan at it."
Note, front fans sound louder because... they're on the front and closer to
your ears. They also have the least impact on case cooling (as they're
typically used home-built PCs) so reducing the speed on those, or
eliminating them, has the most impact on noise with the least impact on
cooling.
Second note, most case 'fan vents' stink. The stamped (round) hole pattern
is a noise maker and it'll reduce the noise if you cut that out to a full
fan hole pattern and use a wire grill. PLUS, the airflow will go up as
well, (bigger hole = less air resistance) which means a low RPM fan will
move as much, or more, air as as your high RPM screamer trying to push/pull
air through those lousy punched holes.
You could try the '7V trick' on your existing fans to quiet them down and
see how effective they are at the lower CFM.
I also see new Dell's more powerful than my PC coming with only one fan.
Dell has the advantage of being able to control the layout of every
component in the system and can optimize the case airflow patterns because
of it. General market case and motherboard manufacturers don't know what
each other, much less the user, is doing and so you end up with 'extra'
effort in places (like a fan on the heatsink).
For an example of how one can 'optimize' things, consider this new solution
from thermaltake
http://www.thermaltake.com/coolers/cl-p0019Fanless103/cl-p0019fanless103.htm
That brings the heat to a radiator that can be cooled by the rear case fan,
in that case a 90mm which can turn slow, quietly, but still move a fair
amount of air. You'll see similar things in Dell cases although they can
avoid the cost of the heatpipe by laying out the motherboard and case so
that a large 'passive' heatsink on the processor lines up with the rear
case fan properly, perhaps with some moderate shrouding to direct the
airflow. And when you control the whole ball of wax you can do even fancier
things with it.
One beautiful example I saw was a Compaq dual P-III work station. Air came
in the front through a cardboard shroud that lead it across the two passive
heatsinks on the dual P-IIIs, was then directed upwards and back to the
front across the motherboard components, then to the rear again across the
hard drives and CD drives, eventually existing out the back. And a low
speed fan to boot. You could hardly tell the thing was on.
Of course, the case, motherboard, PSU, heatsinks, and ducting were all
custom designs that you couldn't duplicate with 'off the shelf' components.
You'd end up with a PSU fan(s), two processor fans, and at least one case fan.
