Info on motherboard: with fan or fanless?

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Hi all,
I'd like to buy a pc with an Amd 6.4 ghz dual core.
A vendor proposes a system based on the motherboard Asus m2n4-sli &...

which is fanless.

What exactly is the difference in performance and reliability between
a fanless motherboard and one with a fan, other than noise? How well
does a fanless system dissipate heath and how long can it stay turned
on without damage? I may be saying something very stupid :) but does
fanless motherboard imply that the processor, too, is not cooled by a

The most cpu-intensive task I'll run is video encoding. I'd like to
run videoencoding at night, while I sleep, in the same room where the
pc will be. So I need some compromise between a pc that goes on fire
and one that keeps me awake with its airplane-like noise :)

Thank you all for your help!

Re: Info on motherboard: with fan or fanless?

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The motherboard chipset is the component that gets hot. It needs some form
of cooling. Generally, cheap motherboards use a heatsink and small (whiny)
fan are fitted and on better quality motherboards, a larger more efficient
passive heatsink is used.

The chipset cooling (fan or not) is nothing to do with the CPU cooler - that
is up to the system builder.

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Then you need to get:

A quiet PSU (power).
Quiet CPU cooler
Some quiet case fans
A Quiet hard disk
A fanless or quiet graphics card.

Tell us more about any gaming you might do, so we can help recommend a
graphics card.

Re: Info on motherboard: with fan or fanless?

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So are fanless motherboards usually cheaper, less reliable systems or
not necessarily?

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To be honest, the game I use the most is the old Worms World Party,
and it's not even 3D! :)
I may try some newer game from time to time, but I wouldn't want to
spend much money on the graphics card just for gaming.
I want one that works with Linux, though, and especially with all the
3d effects of Compiz Fusion.
I was thinking of the Nvidia GeForce 8500 or 8600.

What do you think of the ori series desktop ( /
desktops/ori/) ? I like it because it's Linux-ready.


Re: Info on motherboard: with fan or fanless?

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Not necessarily less reliable and I was generalising when I called them

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I would go for a passively cooled card. I personally have a GeForce 7600 GS
(MSI). Fast enough for all the games I play and totally silent. Sounds like
you don' need anything very powerful, so I would concentrate on getting a
passively cooled, silent card. I would expect any common, but not cutting
edge GFX card runing with a passive cooler would have drivers for Linux
around somewhere.

Re: Info on motherboard: with fan or fanless? wrote:
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Years ago, the chipset chips, called Northbridge and Southbridge, might
have used 2 watts of power. Some were operated, without a heatsink on
top of them, and used ambient cooling. Some had a heatsink attached, and
a noisy 40mm fan. People discovered that if the fan died, the thing
still seemed to work.

Times have changed. The Northbridge chip can now burn up to 20W of power.
The heatsinks are more substantial. Some chips do get hot. The max temp
on some of them, is 99C. Others have a lower number for their max.

To compare heatsinks, I can show you some performance tables. These are
from the Aavid heatsink catalog. Notice that the heatsink removes 3X
more heat, when 200 linear feet per minute of air is blowing
over the heatsink. The heatsink works much better, when forced
air is applied to it. (These would be examples of older Northbridge

                    Length Width Height  still  with
                       mm    mm    mm    air    fan

35x35 374624B60024 35.00  35.00 10.00   23.40  7.55   Black anodize
35x35 374724B60024 35.00  35.00 18.00   15.30  5.15   Black anodize
35x35 374824B60024 35.00  35.00 25.00   12.00  4.27   Black anodize

Whether this is important, depends on the final temperature of the
chips being cooled. If the chip went all the way to 100C, chances
are it would be unstable. Maybe it would corrupt some data on a
random basis. If a Southbridge, maybe the SATA port would no longer
work error free.

Some motherboards allow the chipset temperature to be monitored, so
in fact you may be able to see the temperatures involved.

On some Asus designs, a heatpipe is used. This allows the heat to
be moved closer to the CPU cooling device, where airflow spilling
from the CPU fan, helps cool adjacent heatsinks.

In the case of the M2N4-SLI, the aluminum heatsink is far away from
the CPU, so the CPU fan cannot really help it.

If it gets hot, you may need to add a case fan, and point it at the
heatsink. I use such a scheme, as auxiliary cooling for my video
card. So you can fix it yourself, and you can position a fan
near the thing that is too hot.

Fans have an average life of 3 years, some more, some less. For
commercial equipment, part of preventive maintenance may be to
replace the fans at regular intervals, before they fail. So having
a fan present, means there is potential maintenance to do for it.
In a sense, it is "unreliable", because there is a known wearout

You have to balance that, with the impact on the chipset chips themselves.
If operated at high temperature, for extended periods, maybe that
affects the computed reliability as well. But if the chip fails,
then chances are you'd junk the motherboard. (Maybe it is covered
by warranty, but there would be shipping costs etc.) I would suggest
that adding a fan, and maintaining it, may be better than risking the
motherboard itself.

But it is your choice to make.

I use the finger test, as a quick check. If you burn yourself, touching
any heatsink, that tells you something is running too hot. At that
point, I add a fan for sure.

The M2N4-SLI cooler is obviously designed to save money. The motherboard
is likely a lower cost one. So the emphasis is on reducing the
manufacturing cost.

You can read some reviews by customers, for M2N4-SLI, here.


Re: Info on motherboard: with fan or fanless?

On Thu, 28 Feb 2008 02:49:13 -0800 (PST),

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There is no difference in performance and no difference in
reliability IF the system is otherwise set up properly.

Passively cooled components require more attention to the
chassis airflow and in some cases (typically northbridge
near the CPU socket) may have been designed to work better
with CPU heatsink-fan combinations that blow some air
towards them.

Generally speaking it is not hard to set up a system to
properly cool with a passive heatsink, if the vendor is
proposing a whole system solution then it is his/her burden
to make complimentary selections.

Passive parts do tend to run a bit hotter, it will reduce
your overclocking potential if all else were equal.
Overall, over the life of the system a well designed system
with passive chipset 'sink would be more reliable because
you dont' have the small high(er) RPM fan failure potential
and these fans do tend to be among the shortest lived in the
system (along with video card fans).

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Well enough, given proper system design with a case having
ample low front intake, it can stay turned on indefinitely.

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I recommend an aftermarket CPU heatsink as one can be
selected that keeps CPU cool enough with less noise.  One
low cost alternative is an arctic cooling freezer 64 pro.

Video encoding using semi-modern codecs may prove faster
using a Core 2 Duo based system rather than Athlon 64,
though if running overnight, perhaps the performance doesn't
matter so much as long as it's finished by morning?

Generally the compromise is the right choice of heatsink and
case.  Choose a case with large mostly unrestricted lower
front intake area and at least a rear 120mm exhaust fan.
Side panel fans are optional and generally best avoided
unless the system has particularly high heat producing parts
like a higher end gaming video card(s), or if the wrong case
were chosen which had bad airflow and a side fan were the
easiest remedy....  and even then the typical side fan is a
small 80-92mm size when it ought to have been 120mm and
lower RPM.  Without several hard drives and a gaming video
card the only fan it would need in a typical moderate room
environment is a rear 120mm fan.  

Re: Info on motherboard: with fan or fanless?

Thanks a lot! Yes, most of the encoding will run overnight, so speed
is not crucial, i.e. I'd rather save a bit more and get an AMD.=A0

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