Cooling experts out there, some help please

[Joel Jaeggli]

http://www.netroedge.com/~lm78/cvs/browse.cgi/lm_sensors2/doc/FAQ

> I just tried lm-sensors/i2c on a dual processor PIII system and it
> reports that the cpu temps are +2C when idle and around 16C when
> loaded.  Obviously these are wrong.  The question is, are they
> usually wrong by a constant amount?  So can I assume that my
> cpu's are at something like 32C when idle and 48C when loaded?

it's likely that the value is offset. I'd take a look at the value in the
bios and figure out what the offset between that value and the idle value
is.

> I want to know this because I want to disconnect some of the eight
> fans that the retailer put into this box!  Seems a bit excessive
> to me (and noisy) but I don't want to mess with it without knowing
> for sure whether they are needed.

I typically measure that sort of thing with a thermal probe and a
multimeter. casue the mainboards sensors may not be in useful locations
for extremely accurate measurements.

boxs are typically designed with their worst case rated operating
temperatures as the target for the volume of air they have to move... in
racks in a datacenter, particularly in the event of hvac failure operating
margins afforded but exhausting more air are desirable.

> Anyone have any good recommendations for quiet fans?  Or fans
> that only switch on when things get hot?

panaflo FBA-08A12L. 80mm x 25mm is a pretty quiet (21dba at 1900rpm) 80mm
fan, but it's fairly low volume for a 80mm fan, 24cfm, compared to say a
delta 4300rpm 80mm fan (pretty standard pc fan) which is 48.5dba (more
than 2 orders of magnitude louder) at 68cfm...

Thermally controlled fans are pretty common, but in pc's having the
thermostat on the fan isn't enough, it needs to be on or near the
components you're trying to cools. vendors do make i2c controllers that do
this, but it's a lot of work as a retrofit.

> Dan
>
>
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Joel Jaeggli				       joelja at darkwing.uoregon.edu
Academic User Services			     consult at gladstone.uoregon.edu
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