[LINK] Leave on, or turn off?

[grove at zeta.org.au]

On Thu, 30 Nov 2006, Stewart Fist wrote:

> Has anyone got a reference to a real bit of reliable research which says
> whether it is better to turn a computer off at night, or leave it on 24/7
> (disregarding energy consumption) ?
>
> I guess the question resolves into
> a) the electronics, and
> b) hard-disk-bearing wear.
>
> I've got plenty of so-called 'expert' opinion (mostly in favour of leaving
> computers on), but this seems essentially to be anecdotal only.
>
> Someone, at some time (ie US government departments or the army) must have
> done a systematic test, surely!

I tend to leave my gear on 24x7 unless there's a storm approaching
or if it's a heatwave prediction - we don't have air conditioning at home!

Most hard drives have MTBF ratings (Mean time between failure) 
of values exceeding 80,000 hours or more.   These ratings are 
determined by running the disks at sea level and room temperature 
(about between 20-30c) constantly at full power.   If you run your disks 
at higher temperatures, you start to get a 4x drop in life expectancy
as you get closer to 40c.

With electronics, it's the capacitators and high energy 
components likely to go first.   Generally the power supply 
is the thing that is likely to become unstable as the capacitators 
start to age or dry out.   Fans are the worst - cheap nasty fans 
with no grease in the bearings are the things that lead to more 
failures than anything else.   Lose the fan and it silently 
raises the internal system temperature until things start to go wrong!


rachel

-- 
Rachel Polanskis                 Kingswood, Greater Western Sydney, Australia
grove at zeta.org.au                http://www.zeta.org.au/~grove/grove.html
 	"They who would give up an essential liberty for temporary security,
 	deserve neither liberty or security" - Benjamin Franklin, 1759