[RC5] Adverse effects of participation?

Kevin O'Gorman kogorman at pacbell.net
Wed Jan 26 14:31:08 EST 2000

Darren Tay wrote:
> Hi all,
> Please bear with me, but I feel the need to be reassured that I have
> "nothing to lose" in participating... Some authoritative answers to this
> would help.
> THE Question:
> Will running dnet 24/7 have any adverse effects on computer hardware?
> Last month my old Pentium150 laptop died suddenly. (HDD could not be
> detected) It had been running dnet and doing almost nothing else for the
> last year of its life.
> A friend told me that's what I get for running dnet 24/7. plausible?

Not really.  It might have accellerated the demise by a month or so.

> I think it is an accepted fact that a hdd could be run to death if it were
> at full spin 24/7, no?

Yep, rotating mechanical devices wear out sooner or later.

> (Afterall, hdds are spec-ed with MTFBs)
> What other components can be worn to death from running dnet?

The bearings for fans and their motors, primarily.

> I've always believed the CPU to be immortal since it has no moving parts.
> True? Provided cooling is stable, which brings us to the cooling fans...
> these tend to clog with dust.. Anything else?

See below

> What can I do to make sure the hdd spins down to powersaving (and
> low-wearing mode), when the computer is left alone to crunch rc5?
> Could we have user-definable disk-access frequency in the client?

That's going to vary a lot from one machine to another.  You've gotta look
in the documentation, or actually try it.  It's usually not hard to tell if
a laptop HDD was spinning: it responds fast; otherwise it can take a couple
of seconds to respond to your next mouse click.

> I've been having difficulty getting some household members to approve of me
> letting 3 old laptops run dnet 24/7 in my bedroom.. They think it can only
> be bad for the computers.

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. 

> I'm hoping to hear nice reassuring stuff from you guys!
> Thanks and best regards
> dt
> gluino at bigfoot.com

Kevin O'Gorman  (805) 650-6274  kogorman at pacbell.net
Permanent e-mail forwarder:  Kevin.O'Gorman.64 at Alum.Dartmouth.org
At school: kogorman at cs.ucsb.edu
Web: http://www.cs.ucsb.edu/~kogorman http://trixie.kosman.via.ayuda.com/~kevin

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