[RC5] Adverse effects of participation?

Dakidd dakidd at primenet.com
Tue Jan 25 22:58:32 EST 2000

>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?

According to the 2 years (give or take a couple months) I've had my
collection of Macs doing exactly that, no. Even before I started crunching
blocks, the only time my systems were powered down was when I was upgrading
or moving them, or when a lightning storm was coming in.

I can't even begin to estimate how many "continuously on" hours have been
logged by the machines that you dial into to connect to the internet.

>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?

Chart that one as being roughly as plausible as finding hens' teeth. In a
cow's mouth...

>I think it is an accepted fact that a hdd could be run to death if it were
>at full spin 24/7, no?
>(Afterall, hdds are spec-ed with MTFBs)

A hard drive can die at any time, including the first 30 seconds it's
powered up for testing at the factory. MTBF is a (hideously inaccurate)
estimate <-- Note that word, it's important -- of how long a drive should
be expected to last.

>What other components can be worn to death from running dnet?

None. Period.

>I've always believed the CPU to be immortal since it has no moving parts.

Barring a lightning strike or physical damage, "immortal" is probably a
pretty accurate estimate.

>True? Provided cooling is stable, which brings us to the cooling fans...
>these tend to clog with dust.. Anything else?

In general, if all other things are kept "normal", if the motherboard of a
computer (or any other device built out of solid-state semiconductors)
survives past the first 72 hours of being powered up, it's probably going
to outlast the owner, if not his kids, and probably even his grandkids. Of
course, this doesn't take into account things like power surges, lightningn
strikes, cans of Coke or cups of coffee spilled into the case, being
physically damaged, etc. etc. It also doesn't address the issue of how
useful the machine is going to be after that much time has passed...
However, that's an issue of obsolesence, not wearing out. As an example,
try finding a new version of VisiCalc or Wordstar for an Apple IIe...

>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?

To the best of my knowledge, nothing. The "sleep" or "powersaver" mode on a
computer is primarily intended to save the charge in the batteries of a
laptop. Since you're probably running them plugged into the wall, HD
spin-down, screen dimming, CPU "sleep", and other power-saving measures are
pretty much irrelevant since effectively, you're using a battery that will
never go dead.

>Could we have user-definable disk-access frequency in the client?

Except in a laptop that's trying to conserve battery power, there really
isn't much point.

>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.

They're wrong. Period. A computer that's on 24/7 is actually at slightly
LESS (exactly HOW MUCH less is a subject still being debated among the
experts) risk of failure since it isn't experiencing the jolt of power at
startup time, and isn't having to start the drives spinning. Spinning up
from dead stop is the most stressful time in a hard drive's life -
depending on the specific drive, the power required to spin up from a cold
start can be as much as *100 times* (that's a worst-case situation -
Usually it's closer to 3-5 times) what is required to keep it spinning
while idle! The sudden draw on the power supply to handle that can cause
failure of the system all by itself.

As of right this instant, I've got at least 4 drives spinning that haven't
seen a power-down (other than unplanned outages and downtime for moving
and/or upgrading the machines they're attached to) for more than 5 years.
If they've got any problems, none of my diagnostic tools has been able to
spot them.

Like a lightbulb, a computer (or the parts in it) usually fails at
power-on. Of course, I'm speaking of "in normal use" situations. Lightning
strikes to the transformer outside your house mean that all bets are off!

>I'm hoping to hear nice reassuring stuff from you guys!

Hopefully, this was reassuring enough.

Don Bruder -  Dakidd at primenet.com      <--- Preferred Email - unmunged
I will choose a path that's clear: I will choose Free Will! - N. Peart

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