Archived from groups: comp.sys.ibm.pc.hardware.chips (
More info?)
Robert Myers wrote:
> On Fri, 09 Apr 2004 23:20:50 -0600, Rob Stow <rob.stow@sasktel.net>
> wrote:
>
>
>>Stacey wrote:
>>
>>
>>>Tony Hill wrote:
>>>
>>>
>>>
>>>>Fortunately the chip you've got doesn't consume very much power and
>>>>should be fairly easy to cool. It's TDP is rated at 20.8W, less than
>>>>even Intel's Pentium-M and MUCH less than current Athlon or P4
>>>>systems. A nice big heatsink with either a slow-spinning 80mm fan
>>>>sitting on top or even a passive heatsink with a case fan blowing over
>>>>it should do the trick.
>>>
>>>
>>>I'm going to try one of those zalman Cu "flower" heatsinks made for a socket
>>>A athlon and use as slow a fan as I can get away with. Just wanted to know
>>>what sorta temps would be safe. Right now it never gets over 40C so if 60C
>>>is safe, I got some room. Thanx for everyone's help.
>>
>>I've used one of those with an XP1900+ with no cpu fan -
>>just a quiet intake fan at the lower front of the case and one
>>for outtake at the upper rear. CPU temp was about 68'C
>>under load - a little higher than most people will put up
>>with, but still well within the safety margins.
>>
>
>
> My (ahem) Dell 8100 has no CPU fan as such. The rear case fan
> connects to a shroud which surrounds the CPU heat sink and allows air
> in only through a gap between the shroud and the motherboard. That
> means not only no CPU fan, but the airflow around the heatsink is not
> in hair-dryer mode. It works, and it is _very_ quiet.
I've done something like that - sort of - with an XP2400+,
back in the days when the XP2400+ was thought of as a fast
cpu.
The heat sink had vertical fins. Of course.
I had someone with better welding skills than me put a little
piece of aluminum on the top of the sink, plus two more square
pieces with 3" holes on the two open sides of the sink.
So at this stage the outside of the heat sink is closed off
except for the two round holes on opposite sides of the heatsink.
Next I attached a piece of hose (cut from a large diameter
Shop-Vac type hose) to each side of the heat sink. One of
the other ends of the hose I clipped+taped to the case air
intake fan and the other end to one of the case outtake
fans. Presto - el cheapo ducted cooling for the cpu. I soon
found I could get along without the case intake fan and just let
one of the rear outtake fans do all the work of moving air
through the hoses.
It was *very* quiet. So quiet that someone made me an offer
I couldn't refuse for the system - so I sold it to him. Two
weeks later he was back complaining about how noisy it was -
and I opened up the case and saw that my hard work had been
thrown away and replaced with a conventional heatsink+fan.
>
> Jet noise varies inversely as *eighth* power of the area of the jet
> for a given volumetric flow, so a big case fan is much quieter than a
> little CPU fan to achieve the same airflow. If I really wanted to
> build a quiet CPU and didn't want to go completely fanless, that's how
> I'd do it.
>
> RM
>