[mdlug] computer shutting down

[Dan Pritts]

On Tue, Mar 13, 2007 at 10:19:38AM -0400, allen wrote:
> If you have a spare or can bum a power supply I'd swap the old one out.

(especially) for a server that's running 24/7, invest in a good
power supply.

typical cheap ones run at 50-60% efficiency - good ones at 75-80%.
PC Power & Cooling & Antec both make good units.  I'm sure others 
do too but I don't know other brands.

Say your system draws 100 watts when idle (common).  A 20% loss of
efficiency means ~20 watts wasted, 480 watt-hours/day; ~15
kilowatt-hours/month.

that's not a lot of money on your electric bill, about $1.50 if you
are on DTE.  But over a 3-year lifespan that's $50 and a nice little
extra bit of global warming, acid rain, and mercury pollution
(assuming your incremental electricity usage comes from coal; a
pretty good assumption).

If you run your CPU full-time running SETI at home or something
like that, then add consumption appropriately; in fact, the cheapo
power supply gets LESS efficient as the load goes up.  (i'd also
urge you to consider whether the additional global warming & pollution
of using that extra electricity is really worth the results you get.)

A reasonably good PSU can be had for that $50 and bears the significant
extra benefit that you'll have a known good power source for your
computer.  

danno
--
dan pritts
danno at umich.edu
734-929-9770