Leaving a server on all day

[Mike Jeays]

On Tue, 2004-06-08 at 16:06, Bill Moran wrote:
> Charles Swiger <cswiger at mac.com> wrote:
> 
> > On Jun 8, 2004, at 1:59 PM, Bill Moran wrote:
> > >> Hopefully I'll get my flat screen back soon from repair.  I guess 
> > >> those use
> > >> less power, right?
> > >
> > > I remember having this conversation with someone not too long ago, and 
> > > our
> > > consensus was that flat screens used just as much power as tube 
> > > monitors.  Don't
> > > hold me to that, though, I don't seem to remember our testing 
> > > technique as being
> > > very ... uhm ... "scientific".
> > 
> > No need to guess, use an amp-meter.  :-)
> 
> What a crazy idea.
> 
> I seem to remember plugging monitors into a UPS in an attempt to use the cheesy
> "load meter" lights to tell which was drawing more juice, when that didn't
> show us any difference, we tried watching the power meter outside ... trying to
> guess which monitor made it spin faster ...
> 
> > >>  Also, a 1.8GHz Athlon won't use any more power than
> > >> necessary during idle time, right?
> > >
> > > Different processors are different.  Many newer CPUs will throttle 
> > > their power
> > > consumption while the machine is idle, but most older ones can't do 
> > > this.
> > > You'll need to research the specific CPU + motherboard to see if this 
> > > is
> > > available or not, but (as far as my lousy memory serves) Athlons in 
> > > the 1.8G
> > > range don't support reduced power during non-usage, and will consume 
> > > just as
> > > many watts while the system is idle as while it's doing a buildworld.
> > 
> > A 1.8GHz AMD is likely to be a Barton, or possibly a later-model 
> > Thoroughbred.  The CPU should have AMD's PowerNow! capabilities if APCI 
> > is enabled, and they should also significantly reduce power consumption 
> > if the OS runs the HLT instruction in the idle loop.
> 
> Ahh ... didn't know the 1.8s had that in them.
> 
> > I have one machine with an AMD 1800+ (1.54 MHz T'bred-B), which runs at 
> > perhaps 48 or 50 C if the system is idle.  If I run something like 
> > SETI at Home for a day or so, the CPU will go up to around 56 or even 57 C 
> > as a result of the load.  The difference in thermal output due to load 
> > is very obvious.
> 
> But is thermal output a reliable indicator of power usage?  Logically, it seems
> like it would be, but I'd hate to assume.

Virtually all the power used gets converted into heat that will heat up
your room.

A typical workstation might use 50 watts when idle.  If power is 5 cents
per KW=hour, it will cost you about $2 a month. 50 watts used to heat
your room won't make a lot of difference - just a bit less than a 60
watt light bulb...