[WEB4LIB] Re: Powering down PCs

[Walt_Crawford at notes.rlg.org]

Much as I hate to disagree with Dan, I'm going to.

<Soapbox>
To the best of my knowledge (and I've been following this stuff for 15+
years now), there is NO credible evidence that powering down PCs (when
they'll be out of use for periods of more than an hour or two) will shorten
their life in any real-world sense.

No PC manufacturer that I know of makes such claims. Nor does any hard disk
or display manufacturer, as far as I know.

No body of statistical evidence supports such claims.

PC power supplies are designed to minimize the so-called shock of powering
up. Hard disks, power switches, video monitors, and other "susceptible"
components are rated for, at minimum, hundreds of thousands of power
cycles. Contemporary hard disks aren't threatened by power-down/power-up
cycles. And so on...

Powering down unused PCs saves power (absolutely). That may not be a reason
in areas of unlimited free power generation, but it's a reason everywhere
else, in terms of both direct and indirect costs. Each idling PC may only
use 20-40 watts, but that adds up real fast. (A display without EnergySaver
settings enabled is an entirely different and much more serious matter:
you're talking about a *lot* of energy use for no benefit.)

If you're planning to keep your PCs for 25 years or more, there might be
some bizarre case that burning all that extra power makes them last longer.
Otherwise, they should be turned off for extended periods of disuse. (And
if you are planning to use PCs for 25 years or more, you have bigger
problems than PC life expectancy.)

Given that (a) the national power grid is already near its limits, (b) in
some regions [here, for example], we're already facing rolling brownouts on
certain days, (c) almost all power generation involves global warming and
pollution issues, I think that any advocates of leaving PCs (or other
devices) on permanently need to cite hard evidence. And I don't believe
such evidence exists.
</Soapbox>