[RC5] Adverse effects of participation?

Keith McLaurin skmac at ix.netcom.com
Mon Jan 31 23:49:22 EST 2000


My work experience with semiconductor chip failures
were most often at the bonding pad level which is
stressed by thermal fatigue rather than constant high
temperature. Maybe interconnects have improved over the
years - there are many fewer of them these days. Any
equipment that I want to keep running simply stays on
all the time. The stresses of power on / off is where &
when most of the failures of electronics fails for me.
Most of the burned out light bulbs I replace occur
after the bright flash when I turn the light on. (But I
still advocate keeping the lights off in my house as
the 1000 hour life is too short to leave them on and
electricity is US$0.14 per kwhr).

Peter Cordes wrote:
> 
> On Wed, Jan 26, 2000 at 02:31:08PM -0800, Kevin O'Gorman wrote:
> 
> > Well, I have bad news: most semiconductor failures come from the slow dispersion
> > of the "doping" (impurity) atoms through the crystal matrix of the substrate
> > (silicon/germanium).  The dispersion rate increases with temperature, and
> > even with cooling fans, it's going to be faster when the machine is running than
> > when it is not.
> >
> > I also have some good news: this effect is usually minimal, and chances are the
> > machine will be hopelessly obsolete before it breaks even under 24/7 conditions.
> > I run two of my home machines 24/7 and I've been doing this for 15 years
> > or so (since 1985) and I'm not going to stop now.
> 
>  Old CPUs used much bigger transistors which are less affected by dispesion
> of doping atoms across the junctions.  Modern CPUs have very small
> transistors, only a few hundreds of atoms across (IIRC :).  They will wear
> out faster under continuous full-power use.  (It still takes a long time,
> probably more than 10 years, but it might take 20 or 30 years if you usually
> had a light load so the kernel could execute halt instructions to save
> power, or even use APM to shut down the whole mobo.  (of course, then
> powering up from that is a bit like turning on your computer, so a bit hard
> on things.))
> 
>  But seriously, I wouldn't worry.  People do run 24/7 e-commerce sites off
> retail CPUs.  (e-commerce web sites require the server to do some work to
> generate each page, especially https encrypted connections, so typically the
> system load will be "up there" on a busy site.)  They don't usually break
> down :)
> 
> #define X(x,y) x##y
> DUPS Secretary ; http://is2.dal.ca/~dups/
> Peter Cordes ;  e-mail: X(peter at cordes.phys. , dal.ca)
> 
> "The gods confound the man who first found out how to distinguish the hours!
>  Confound him, too, who in this place set up a sundial, to cut and hack
>  my day so wretchedly into small pieces!" -- Plautus, 200 BCE
> 
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