[nmglug] Power Variation on a 266 P2

[WA7BSZ]

  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.  

Unless you don't decrease in the amount of electricity when it gets
warmer, your bill might go down even if the computer uses more KWH. 
You may have less electric fan use in the heater, depending on how many
KWH that uses.

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.

OK, this morning I turned on an old P2-266, even less power than a 400.
 It is a Compaq with a 10G drive and 256 MB mem.  When it is running it
seems to have two states of current draw.  When it is idle it is
drawing about 0.48 amps, and when it is running Tuxracer, or top with a
-d 0.1 command tail, it is running 0.76 amps, according to the AC
current meter I hve on a variable AC supply.  If we don't consider
power factor and just use these numbers, we have  about 58 Watts idle,
and 90W when it is using the processor over 50%.  I could watch the
current meter jump for every keystroke on the command line when it was
otherwise idle.  Also, it takes about 2 minutes just to move the cursor
to Quit in Tuxracer, so that pretty well takes over that 266 MHz
computer, like you would expect.  

So, if I leave that computer on all the time, and the rates for KWH
past the first 200 KWH are about 8 cents per KWH, as the latest PNM
schedule says, then it will cost me, for a 30 day month, about $3.50 at
standby, and about $5.20 if it is hard at work helping SETI all month. 
The processor will be hotter too.  So if I had 8 of these, that would
be $28 for idle (why would I have 8 idle computers on anyway?) and
$41.60 for them calculating all the time.  That is for 266 MHz
computers.  That would be a continuous 720 Watts, like 3/4ths of a
space heater on all the time in a room.  So that would cost even more
to air condition the room to keep them from burning out in the summer.

I had a 2.8 GHz P4 with the meter on it, and it would run 2A while it
was calculating, so that is 240W for one computer, and it did heat up
the room a lot in the summer.  That would be $14 for each one of those
you had running all the time.  So, if you had 8 of those, that would be
$112 a month.  Maybe you could make them available for calculating for
tax deductible causes, and deduct $1344 a year from your taxes?  If you
can buy 8 newer computers just to use to help some organization,
another $112 a month is not a factor.


		
__________________________________ 
Do you Yahoo!? 
Yahoo! Small Business - Try our new resources site!
http://smallbusiness.yahoo.com/resources/