[rescue] This Just In: HP to buy Compaq

[Greg A. Woods]

[ On Saturday, September 15, 2001 at 23:44:32 (-0400), Kurt Huhn wrote: ]
> Subject: Re: [rescue] This Just In: HP to buy Compaq
>
> My dual PPro Compaq Proliant 800 has no fans on the heatsink.  The heatsink
> ain't even all that grand.  I'll defer to the Compaq engineers on this one -
> because I am a drooling idiot when it comes to thermal dynamics...

Intel's spec sheet does not mention any example without some airflow

However Compaq no doubt have ensured there is enough air flow across the
heat sink when the power supply and/or chassis fan is operating
correctly.

Undoubtably though that means you cannot safely upgrade the processor
without adding a fan.  The requirements for 40W dissipation as opposed
to 30W are quite different.

The Intel specs require the PPro case temperature be at 85 C for ideal
operating conditions (I can't find any spec of the junction-to-case
thermal resistance, or even of the case-to-sink thermal resistance).

In their thermal analysis they only give the case-to-ambient thermal
resistance including the heat sink for various heights of standard PPro
heat sinks (dimensions and design of which are clearly specified) and
given various amounts of air flow across that heat sink.

They also give the ambient temperatures required at the heat sink fan
intake for 29.2W and 40W to achieve the 85 C case temperature.  That's
where I got the 400 LFM over a 0.5" high heat sink value for normal room
temperature.

After reading my IC textbook again I'm wondering what issues there might
be for running a PPro below the specified case temp.....  I have had the
odd unexplained core dump even though I'm running ECC RAM and as far as
I know I have never had any single-bit errors reported (though I was
recently reminded that ECC won't necessarily protect from a whole chip
failure if the array orientation is in such a way that a chip failure
would cause a multi-bit error that might not be detected).

-- 
							Greg A. Woods

+1 416 218-0098      VE3TCP      <gwoods at acm.org>     <woods at robohack.ca>
Planix, Inc. <woods at planix.com>;   Secrets of the Weird <woods at weird.com>