[RC5] Adverse effects of participation?

Martin Harvey martin at pergolesi.demon.co.uk
Wed Jan 26 18:57:13 EST 2000

Darren Tay wrote:
> 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?


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

Not really. The mean time between failures of hard drives is about 10
years at 24/7, and normally drives either die after a few months, or
they keep going essentially for ever.

On most drives, turning them off and on causes more damage than leaving
them running 24/7. I know of many bits of equipment (10 year old
fileservers) that were turned off for Y2K, and the increased load when
turning the drives back on resulted in drive failure.

Most people now accept that the easiest way to achieve hardware
reliability is to have a machine in a cool low humidity environment, to
turn it on, and leave it permanently on. Statr up loads or far more
damaging than continuous use.

In my opinion, the biggest factor on how long drives last is background
vibration, humidity, and how well they are cooled. In all my years, I've
had 3 drives fail: one was a head crash, one was a motor overheat, and
one was knackered electronics. They all failed when I was living next to
the sea with humid salty air, which wreaks havoc on electronics.

> (Afterall, hdds are spec-ed with MTFBs)

Correct... however, the MTBF is continuous running time, and no mention
is made of startup loads mainly because it's hard to predict turn-on

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

Nothing, provided the CPU is not overclocked, and cooled adequately.

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

No. All integrated circuits suffer from thermal diffusion to a greater
or lesser degree. If you overclock your CPU, and don't cool it, you can
have reliability problems down the line. For a properly cooled CPU, you
might have reliability problems about 100 or so years down the line.
They're certainly not immortal.

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

Not really.

> 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?

Disk access frequency is not really a factor in HDD failure. Most of the
drives that failed on my machines were backup drives which were used
relatively infrequently.

> 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.

Nahhh. It's pure scaremongering based on a lack of knowledge. Start up
is by far the most stressful time for all electronic and
electromechanical components. Many businesses and people (including
myself) have computers that run 24/7 with no problems at all.

Anyway... most cash machines are now PC's running NT, they run 24/7, and
when was the last time you saw a hardware failure in one of them?


Martin Harvey. martin at pergolesi.demon.co.uk

The Usenet Oracle has pondered your question deeply.  Your question
was: Will your answer to this question be in the negative?
And in response, thus spake the Oracle: Memory fault.  Core dumped.

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