On Tue, 13 Apr 2010 02:41:26 -0500, edfair
wrote:


Some have come to the conclusion that it is better to switch everything
off if the macine is going to be unused for more than 4 or 5 hours.
There is a tradeoff involved, thermal shock vs continual erosion of
traces, extra cost of machine repair from surge at power-up vs power
load at idle.

This question can generally be counted on to start a flame war. People
have strong opinions and there has been little investigation to prove
the results either way.



.... but there is supporting evidence. It depends on the
particular weakness of the entire *system* and by system I
also mean the power grid.

Basically the evidence comes from tracing fault modes,
looking at dead equipment rather than formal testing long
term which serves little use - by the time meaningful data
was a accumulated nobody wants to build a new system with
old parts and it would have to be based on the contemporary
tech of the time as merely deciding a "disk drive" is a
"disk drive" is not enough, the designs change too much over
the years to combat failure modes as much as the design
budget will allow.

Will it be subject to significant power spikes? IF so then
certainly turning it off at a power strip will reduce # of
events seen on average.

Leaving it running tends to be most problematic if it uses
poor capacitors or fans so their lifespan elapses before the
viable lifespan of the system is up. Turning it off tends
to wear out the battery faster. Thermal shock is not much
of a consideration though, if we concede it will not damage
equipment signficantl within its viable lifespan which seems
to be the case with all but the rare instances of
manufacturing solder pad defects or in-chip solder bump
defects as seen with certain chipsets in recent history.