[nmglug] Spare P2s all running from one big power supply

[Mars DeLapp]

Tim Emerick wrote:
> What can I say but.....WOW!
> 
> That is about as comprehensive as answers get.
> 
> I didn't think about the 2way communications with the ps and the mb.  I would
> imagine that would present a problem.  Sounds like if I REALLY wanted to set
> them all up and just run BOINC it would be easiest to just stack them up in a
> corner and let'em run.
> 
> Hmmmm....$30-$60/month for the electric bill seems a bit steep for the amount
> of processing power that the P2-400's would produce.  I think I'll set them
> up and see what the next months bill looks like.  I don't know that much
> about electricity but I sure will notice a spike in the bill.  LOL
> 
> The area of your explanation regarding power usage during intensive tasks
> (calculating weather/flashplayer) was very interesting to me.  I thought that
> the CPU and motherboard components drew a steady stream of power regardless
> of what they were doing.  Very very interesting.  I recently installed
> BOINC/Seti at home on my two main machines at the house.  They are set to
> process after 5 minutes of user inactivity.  Now I'm curious to see if there
> will be a spike in my electric bill with just those two computers (P3-500 &
> P3-700).

Get a Kill-a-Watt power meter and you can know exactly how much power your appliances are using.

I got mine for $29 on sale a Radio Shack. They usually cost $39.

http://tinyurl.com/3qcv3

I am not sure that those old motherboards have power controls. It seems my old P2 300 MHz machine had to be turned on 
and off by the switch.

AT power supplies have four power supplies in them: +5 Vdc, -5 Vdc, +12 Vdc and -12 Vdc. You need to make sure you don't 
exceed the Amp ratings of each of those four sources. As an example, pulling 300 Watts from the -5 Vdc source of a 500 
Watt is going to fry it. (actually, it should shut down and not burst into flames.

Nobody mentioned reset switches, power switches, shielding and static protection that cases provide. If it was me, I 
think I would opt for using the cases and come up with another creative idea for a conversation piece. Maybe screw a 
bunch of old hardware to the garage ceiling in a constellation pattern, wire up some LEDs on them, and connect that to 
the pile of PCs in the corner. Then tell people the parts on the ceiling are an antenna used to communicate directly 
with extraterrestrials.

Mars

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J. Marsden DeLapp, PE
President
DeLapp & Associates, Inc. dba DeLapp Engineering
Providing lighting and power planning, design and analysis services
for commercial, industrial and large residential facilities.
1300 Luisa St Ste 23
Santa Fe NM 87505
(505) 983-5557
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