what is "fanless" cooling?

[Gwen Morse]

This is part of the description of my new motherboard: "MN232-SLI
Deluxe WiFi is a fanless heat-pipe Chipset cooling system"

I can sort of follow the most basic discussions about "fanless"
cooling. It appears to be an attachment that clips to my cpu (instead
of a cooling fan), but, it serves the same purpose -- to wick heat away
from the CPU. The main benefit would presumably be that it's quieter
than yet another fan in the case (along with drawing less power, etc).

What are the downsides? When reading over the AMD cpu warranty it said
in no-nonsense terms that the cpu was only warranteed if I used the fan
included in the box (or maybe that was the tiger direct return policy).
Anyway, I read that I was supposed to use the included fan and so I
did.

Now I have my Cool and Quiet cooling block sitting in a box unused. Can
I set up my PC, make sure everything is working internally, and then
swap out to that block? Do I "have" to stay with the fan since it had
all that thermal paste on it and now it's bonded to the CPU? If I want
to switch to the cooling block, do I need more thermal paste?

Is there a novice description of these things and what I'm supposed to
do (or not do) to get the Cool and Quiet heat block working without
frying my cpu?

Gwen

 

[Tweek]

The fanless part of that motherboard is a heatpipe cooler on the chipset of
the motherboard. The heatpipe usually goes to a block of cooling fins at the
rear of the mainboard. Your CPU still needs a cooling fan. In fact, the
heatpipe cooling usually relies on the air coming from the cpu fan to
facilitate cooling of that part.

 

[Paul]

This is part of the description of my new motherboard: "MN232-SLI
Deluxe WiFi is a fanless heat-pipe Chipset cooling system"

I can sort of follow the most basic discussions about "fanless"
cooling. It appears to be an attachment that clips to my cpu (instead
of a cooling fan), but, it serves the same purpose -- to wick heat away
from the CPU. The main benefit would presumably be that it's quieter
than yet another fan in the case (along with drawing less power, etc).

What are the downsides? When reading over the AMD cpu warranty it said
in no-nonsense terms that the cpu was only warranteed if I used the fan
included in the box (or maybe that was the tiger direct return policy).
Anyway, I read that I was supposed to use the included fan and so I
did.

Now I have my Cool and Quiet cooling block sitting in a box unused. Can
I set up my PC, make sure everything is working internally, and then
swap out to that block? Do I "have" to stay with the fan since it had
all that thermal paste on it and now it's bonded to the CPU? If I want
to switch to the cooling block, do I need more thermal paste?

Is there a novice description of these things and what I'm supposed to
do (or not do) to get the Cool and Quiet heat block working without
frying my cpu?

Gwen

The heatpipes used on the chipset chips, move the heat from the
top of the chip, to some other place on the motherboard. Since
your typical air-cooled processor blows air down onto the
motherboard, in the vicinity of the CPU socket, the fins at the
end of the heatpipe are located to collect this "spill" cooling
air that is coming from the CPU fan.

In short, the "fanless" cooling is an attempt to make the CPU
fan do all the cooling for the motherboard. The theory is,
there is less noise if just the CPU fan is being used.

If you bought a heatpipe motherboard, and then bought a
water-block cooling system for your CPU, then there is
no longer a lot of air movement in the CPU area. In that
case, some of the Asus boards come bundled with a separate
fan that mounts onto the fins on the end of the heatpipe,
and blows air through the fins. That is an alternate way
to get the necessary cooling.

http://estore.asus.com/shop/item.asp?itemid=232&catid=131

The fins at the end of a heatpipe could rely on "convection"
cooling, with the rising heat pulling a tiny bit of air
through the fins. But then the amount of cooling surface
area required would be quite large, and take up a fair amount
of space inside the computer case.

The main benefit of the heatpipe, is mostly from comparing
it to the alternate solution. They use a heatsink and a low
profile fan running at 5500 RPM or so, on top of the chipset.
That can be quite noisy and failure prone. You could replace
the chipset cooler with something like this:

http://www.swiftnets.com/products/mcx159.asp

but then the video card would likely bump into one of those.

So the heatpipe may make the plug-in card area a little
better, but the heat still has to go somewhere, and some
air movement is still required.

Paul

 

[coolsti]

Is there a novice description of these things and what I'm supposed to
do (or not do) to get the Cool and Quiet heat block working without
frying my cpu?

Gwen

It might be interesting to do a Google search on heat pipes and see what
they are all about. I thought initially that they were just a highly
conductive metal, sort of like a huge cooling fin. But a friend told me
that there is some sort of liquid inside and it is the special properties
of this liquid going through phase changes as its temperature changes,
which extremely effectively can pipe heat from one location of the pipe to
another. My friend told me he was playing around with one, and put it in a
hot cup of coffee holding the extreme far end, and immediately burnt his
fingers.

I have a heat pipe in my Asus 8N32-SLI mother board, but for the chipset,
not the CPU.

The heatpipe basically moves the heat away from one location to another,
but this will only do anything for you if the heat at the "other" location
can be adequately removed. So you still need air circulation and transfer
by some other fans in your PC, but with a heat pipe you can move the heat
to somewhere where you have room for heat transfer fins, so that another
fan, like your cabinet fan, can do the heat removal.

 

[Gwen Morse]

Thanks to everyone for the responses on this.

I was reading over my documentation on what the little extra peice was
for, and it turns out to be a fan-less cooler if I'm watercooling my
PC.

I just put it back in the box with the other cables and bits I'm not
using.

Gwen