1U P4 Systems

[Steve Gaudet]

Hello Josip,

> > Based on the current P4 die won't see the P4 in anything smaller than
> a 2u.
> 
> Except for the P4/1.4 1U RackSaver link posted by Tim...  However,
> cooling a 1U case concerns me.  The RackSaver RS-1100 claims to have 6
> small case fans (> 40 cfm total), and a 250W ATX12V power supply.  I
> understand the need to be space efficient, but I'd feel more confident
> about cooling with larger cases...

After reading the article posted by Brian Atkins and throttling were ore 
concerned about heat.  

---------from Brian Atkins------------

The throttling may not be solvable, even with mega-cooling methods due
to internal hot spot(s):

http://www.inqst.com/articles/athlon4/0516main.htm

Throttling will vary chip to chip because of thermal diode inconsistencies.

Intel must have developed a huge case of big-company-arrogance in order
to make all the bad decisions they've made over the last few years.
-- 
Brian Atkins
Director, Singularity Institute for Artificial Intelligence
http://www.singinst.org/
=================================================================


As also mentioned before on this list, Intel ships a hugh heat sink which would 
never fit into a 1u.  Therefore, coming up with an alternative is a task that 
should not be rushed because their are warranty issues on both the motherboard 
and processor that we here at Angstrom want to maintain. Failures due to heat 
are easy to see, throttling down issues can go undetected.

This isn't suggesting Racksaver dosen't have a solid solution, I'm sure they 
do.  However, from what I've seen they are the only ones...and there may me a 
valid reason for this.



> P.S.  RackSaver uses P4/1.4 which can dissipate 51.8W.  By contrast,
> the
> P4/1.7 can dissipate 64.0W in normal use, i.e. more than a fairly large
> soldering iron...  BTW, this 64.0W is Intel's "thermal design point"
> for
> the P4/1.7 processor.  Their "thermal design point" is based on 75% of
> the maximum power dissipation (which could reach 85.3W, lead to
> internal
> hot spots, etc.).  Intel claims that most popular applications
> (including SPEC benchmarks) fall below this 75%.  However, ATLAS and
> some other cache optimized codes can seriously stress this
> assumption...  Excellent cooling is essential when doing very intense
> computations.
> 
> -- 
> Dr. Josip Loncaric, Research Fellow              

Regards,

Steve Gaudet
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