Leaving Dell Dimension 8300 running 24/7 ...?

Discussion in 'Dell' started by Thomas G. Marshall, Feb 12, 2005.

  1. Thomas G. Marshall

    w_tom Guest

    Once we put numbers in perspective, then what a finger calls
    'major temperature change' is near zero temperature change to
    electronics. Instead, too many humans *feel* they know what
    is a major temperature change; what must be stress; numbers be
    damned. In reality, the trivial temperature change means
    stress from power up is virtually zero.

    How does temperature change affects semiconductors? Well
    that semiconductor was made by temperature cycling more than
    400 degrees with every (and numerous) production cycle. Why
    is 400 degrees significant? Because 400+ degrees is not
    significantly stressful to the semiconductor. Some will
    attempt to claim temperature changes of only tens of degrees
    is stressful? "Give me a break" ... I believe is the name of
    that book. These are numbers. Power up is stressful to
    semiconductors when we talk about many hundreds of degrees of
    temperature change. Too many forget to provide numbers when
    they speculate. Some think power up is stressful only because
    a finger gets hot. Nonsense - or also known as junk science

    There was this old rule in electronics design. It's not too
    hot if you don't leave skin. That's right. Semiconductors
    even that hot were considered within a perfectly good

    Once we apply numbers to the concept, then thermal stress
    during powerup is virtually zero. And that is the point.
    Until he can provide numbers such as those from manufacturer
    data sheets, then he is only promoting myth: junk science
    reasoning. He provides no numbers based in science, nor
    numbers from manufacturer data sheets. A damning fact that
    every lurker should have immediately noted. Where are his
    numbers? No numbers means junk science reasoning. Repeated
    because too many Americans (such as those who sent seven Space
    Shuttle astronauts uselessly to their death) ignored the
    concepts. No numbers means junk science reasoning as too
    commonly found in business school rationalizations and junk
    science reasoning.

    A very embarrassing question is asked. What is the
    component overstressed by powerup? And don't forget to
    provide the numbers.
    w_tom, Feb 16, 2005
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  2. Thomas G. Marshall

    Sparky Guest

    Well bless your blessed location! Locally we had a blackout 2 summers
    ago and an electrical failure the summer before after a thunderstorm
    (NYC area). IIRC the blackout hit about 5 PM and we didn't get the
    traffic lights back on or cable service restored until about 6 AM the
    next day. Regular household service flickered a couple of times, but
    never went out.
    Sparky, Feb 16, 2005
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  3. Thomas G. Marshall

    Sparky Guest

    Actually, I'd prefer to write a REXX script; but that's an entirely
    different smoke.
    Sparky, Feb 16, 2005
  4. w_tom coughed up:


    "junk science" as you put it also makes a rash assumption that numbers by
    themselves mean something. Numbers and facts in general are *only as good*
    as their interpretation.

    *AND* numbers and concepts do not come close to being as important as actual
    observations are. Steve has observed over time many machines that on/off
    machines fair much worse than the 24/7 machines do.

    I still don't see an answer from you resolving this.

    Thomas G. Marshall, Feb 16, 2005
  5. User N coughed up:
    Don't know yet. I routinely scan with AVG as well.

    I can only assume that the retention on your news server is less than 2 or 3
    days, which is very unfortunate for you. The line of my thinking is in my
    original post. I am not sure of any of this, so don't pretend that I have a
    strict opinion one way or the other----that is the reason for this thread in
    the first place.

    The fundamental reasons for me wanting more than a week scan is that an old
    and well known trojan slipped right through the auto-protect, but was caught
    on the scan. I am considering placing more of a burden on the scanning for
    this reason.
    Thomas G. Marshall, Feb 16, 2005
  6. Thomas G. Marshall

    Dave Budd Guest

    otoh, he has many more on/off to observe, iirc: the pool sizes
    are very different.
    having done some stats, i can say that you can't judge from the
    absolute numbers, or the ones you get by dividing by the sizes
    of the two pools: it's more complicated than that.
    it does give you a good first estimate though
    Dave Budd, Feb 16, 2005
  7. Thomas G. Marshall

    w_tom Guest

    We gave him a newspaper article from the tabloid. He read
    it and drew an obvious conclusion. We then provided the same
    story from a NY Times, Washington Post, or WSJ type
    newspaper. Much longer article with those underlying details
    created an obvious 180 degrees different conclusion. That is
    the point. The 'leave it on' theory does not provide details
    and even contains contrarian facts. IOW if it was accurate,
    then we must also recommend leaving on the TV, radio,
    incandescent light bulbs, and CRT.

    Why do they not recommend leaving a CRT on? After all,
    power up inside a CRT means much higher voltage changes, and
    many times higher temperature changes. Clearly if anything
    was more susceptible to power on stress, it is the CRT. And
    yet the same conclusion that says 'leave a computer on' also
    says power off the CRT?

    Reasons for this contradiction would be found in missing
    details. For example some possible missing details: a
    location with 2000 computers use newer Dell computers and not
    any clones? Clones, both by example and for reasons
    technical, have a greater failure rate. Is the building AC
    power delivered properly earthed? How utilities enter a
    building also will significantly affect hardware life
    expectancy. So the 2000 'always left on' computers were also
    in a newer steel and concrete building with properly earthed
    utilities? Even the building can affect hardware life
    expectancy. How much does the new equipment sleep? Then it
    is really power cycling. Extending hardware life expectancy
    by doing frequent power reductions and yet *assumed* to be
    always on. These missing details are damning to the

    Once we looked at actual failure rates considering other
    variables such as quality of manufacturer, age of equipment,
    how building was constructed, what actually failed, energy
    star actions, and human biases, then with all things being
    equal, we discovered no measurable difference but lots of
    consumed electricity. The repair people just felt they were
    spending less time repairing when systems were left on. They
    had just observed without numbers and without the essential
    details - and just knew.

    Why did they not recommend leaving powered TVs, radios,
    light bulbs, and the CRT? Clearly if an observation alone is
    sufficient, then leaving powered all other electronics
    including that CRT must be recommended. Why the
    contradiction? Once underlying details were examined, such as
    how things fail and what really does fail, then those 'leave
    it on' observations fall apart mostly as examples of human
    bias and problems created by not understanding underlying

    He made a 180 degree different conclusion once he read
    details in that non-tabloid newspaper. And that is the
    point. We have seen for decades that 'leaving it on' does not
    preserve life expectancy once we consider the details. We see
    obtain same in manufacturer data sheets. And yet, on a simple
    observation without the always necessary details, one can
    contradict decades of experience and published technical
    numbers? Again the damning point. If leaving computers
    'always powered' extends their life expectancy, then it must
    also do same for TVs, radios, light bulbs, and CRTs. Why do
    they not recommend leaving powered a CRT that would suffer (if
    it exists) even greater from 'power on stress'? This last
    sentence alone is damning. And again, the answer is found in
    missing details.

    Observations without both underlying concepts, numbers, and
    without essential details from each example make that
    observation nothing more than speculation. The concept of
    'leave it on' is not justified, repeatedly, once we have those
    details. The concept of 'leave it on' flies contrary to
    decades of technical facts. What is missing in his example?
    The numbers - important details. Provided was only a personal
    observation without the always necessary facts and numbers -
    the details.

    Provided in a previous post were details about UPSes. IOW
    those details demonstrate that plug-in UPSes (and filters, et
    al) do nothing for hardware life expectancy ... if the
    hardware is properly constructed to meet industry standards.
    Again, many also claim improved life expectancy from a UPS
    using the same observation only technique. Using observation
    alone, they obtain junk science conclusions.

    Without those essential and missing details, they obtained a
    180 degree different conclusion. Observations alone are never
    sufficient for facts. Never. Observations alone are
    sufficient for speculation. Observations without "numbers and
    concepts" create junk science conclusions.

    w_tom, Feb 16, 2005
  8. Thomas G. Marshall

    Roger Wilco Guest

    Feed-throughs (in case you don't know, that is part of a circuit board).
    I didn't say component failure of solid state devices, I said parts that
    were otherwise considered non-moving parts. Hell - semiconductors can
    fail for no reason just sitting in a parts bin - and yet to some extent
    temperature (or sometimes heat) can damage them. The non-moving parts I
    referred to are not actually stressed (you said stressed, not I) they
    are fatigued. And as to the topic of powerup itself, it is not the
    weight (stress) it's the reps (reference to weightlifting there).

    Sorry, no numbers - just facts.
    Roger Wilco, Feb 16, 2005
  9. Thomas G. Marshall

    Ben Myers Guest

    This is now a thread that is running 24/7. :) ... Ben Myers
    Ben Myers, Feb 16, 2005
  10. Dave Budd coughed up:
    Correct. At this point, and with this issue, I'll take anything that is
    based upon unbiased population domains.
    Thomas G. Marshall, Feb 17, 2005
  11. w_tom coughed up:

    Not "damning", it just makes the observation less (or un-) supported:
    Damning means full contradiction---it is not strong enough to fully
    contradict it yet.

    Good. You have /now/ given me what I've been asking for: a rationale that
    explains steve's observations. Your prior suppositions on miscategorizing
    the failures found did not address his observations at all.

    The next step is to evaluate your rationale. Perhaps we can decide one way
    or the other soon. But probably not, since this has been regarded by others
    already as a never ending debate.

    Cart before the horse. Facts are derived from observations. And facts
    themselves are of no use as such. Facts /require/ interpretation. And the
    interpretation is what is most often argued about.

    Again, cart before the horse. The observations include the numbers (as
    measurements), and then form the concepts. The only time this is reversed
    is when the concept is first, and then it is a hypothetical.

    We're spinning in circles on this one. I'll not argue this detail any
    longer, since I couldn't care less about it. I am more interested in
    analyzing the possible reasons you've given for steve's observations not
    indicating 24/7 as the winner. /That/ is what's important. /That/ is what
    will help iron out the debate.
    Thomas G. Marshall, Feb 17, 2005
  12. Thomas G. Marshall

    User N Guest

    FWIW, Giganews retention is pretty good... over a year in text groups.
    Please forgive me for the additional questions. You did mention that
    you'd be scanning with NAV2003 and communicate that it only picked
    up on the byte verify threat during a full scan. But alot of people utilize
    multiple anti-malware tools and some choose to perform full scans for
    other reasons (like they haven't figured out how to prevent their SO
    from disabling real-time protection when it gets in his or her way).
    FWIW, I use AVG and I've seen the same thing. I'm not terribly surprised.
    I believe the most common/generic approach to real-time scanning is to
    hook into the filesystem and scan when a file is opened. If a program just
    downloads an object into memory, or saves it to a new file and accesses it
    without closing and reopening the file, the real-time scanner won't be able to
    catch it at that time.

    AVG, at least, supports an "on-close scan" option (off by default I believe).
    Given the name and all, I suspect it simply triggers the scanning engine
    when files are closed. There would be more overhead (twice the scanning
    one would think) and it wouldn't seem to prevent any attacks (I believe
    they say it won't make you any safer), but it should automatically catch bad
    files earlier (ie before they are caught by a subsequent open or full scan).

    There are other ways to achieve real-time scanning. For example, via
    network proxies and hooking into the applications that download things.
    I'm not familiar with all the features that are available with the various
    desktop anti-malware tools. But I believe I've come across solutions
    that offer real-time scanning for malicious applets, javascripts, etc. If
    the idea of catching things *before* they can infect your system appeals
    to you (full scans are of relatively little use in terms of prevention), you
    might shop around.
    User N, Feb 17, 2005
  13. Thomas G. Marshall

    w_tom Guest

    The manufacturer so undersized a fuse that in a warm room,
    the fuse would blow. That is proof that heat causes failure?
    No, that is proof that the design is defective. The observer
    may blame heat only because he first did not learn facts ...
    the underlying details.

    Feedthroughs fail due to trivial thermal cycling? You would
    accept this as an example of how thermal cycling is so
    destructive? Again, it is a manufacturing defect so heinous
    that it must not exist with any computer model. Am I to
    assume this is the reasoning that also promotes the myths
    about power cycling being destructive? Feedthroughs fail due
    to thermal cycling? That was not acceptable even 30 years

    If your solution to PC board feedthrough problems is to
    avoid trivial thermal cycles - to always leave a computer on -
    then I also have an East River bridge I can sell you. That
    feedthrough is not - by any means - an example of a component
    overstressed by powerup. It is a classic example of a
    manufacturer with a very seriously defective product - or an
    isolated and extremely rare failure.

    But again, what is this component rumored to be harmed by
    thermal cycling?
    w_tom, Feb 17, 2005
  14. Thomas G. Marshall

    w_tom Guest

    Actually we are not spinning wheels. For example, we
    finally have someone willing to suggest a details. That
    thermal cycling caused PC board feedthrough failures. That
    detail says thermal cycling (again) did not cause the
    problem. The problem is directly traceable to a manufacturing
    defect that must not exist in any electronics. Power cycling
    got blamed only when an observer saw a failure, then
    speculated without sufficient facts: blamed failure on thermal

    Notice how those who speculated power cycling was so
    destructive are no longer defending that claim - once we
    demand underlying details. IOW we are making great progress
    as myths are replaced by silence. Why? Underlying reasons
    for 'rumored to be destructive' power cycling do not exist.

    IOW observation - that the computer failed due to power
    cycling - was found erroneous once we add underlying details.
    Why did the feedthrough fail? Is the computer manufacturer
    that deficient? Or is the computer owner a bean counter type
    that uses only one number - price - to make decisions? Either
    way, defects aggrevated and exposed by thermal cycling say the
    defect is due to other completely different reasons.
    Observation alone (again) would not be sufficient to learn
    that conclusions. But once we have underlying facts - that
    feedthrough failed - then we know power cycling was not the
    reason for failure. Power cycling only exposed symptoms of
    another completely different problem.

    Still waiting for someone to provide components that would
    be damaged by power up. Many were willing to post when it was
    speculation: power cycling is so destructive. Now that we are
    down to the reasons why, the responses are 'thread bare'. And
    that is the point. Those who claim power cycling is so
    destructive don't learn the whys - they only speculate. IOW
    they are easily deceived by the myths of power cycling rather
    than acutally learn facts. Again, what component is being
    damaged by power cycling?

    w_tom, Feb 17, 2005
  15. w_tom coughed up:
    No, the spinning I was talking about has to do with the notion of concepts
    vs. numbers vs. facts vs. observations. I'm not interested in that.

    No. Now I see where the spinning takes place. What you are referring to as
    observation is /conclusion/. The observation is the failed computer.


    I've seen this a few times---Don't make this mistake:

    Dwight: "This thing is wildly available."
    Smedly: "Did you mean wildly, or /widely/ ?"
    Dwight: "Both!", said while nodding emphatically.

    Dwight was exposed to have made a grammatical
    error and tries to cover it up by thinking
    fast. This is so painfully obvious that he
    only succeeds in looking worse.
    Thomas G. Marshall, Feb 18, 2005
  16. w_tom coughed up:

    w_tom, *please* do not top post after others have bottom posted. It makes
    it impossible to reply to with an interleaved-posting style, and makes the
    conversation a headache to follow.
    Thomas G. Marshall, Feb 18, 2005
  17. Thomas G. Marshall

    Roger Wilco Guest

    You sound like an engineer who has never had to repair anything. :)

    The engineering and the manufacturing process is designed to increase
    the mean time between failures and if it were possible to eliminate the
    causes of failures. You sound like the ol' "I didn't kill him - I pushed
    him off the cliff, the fall killed him - no it didn't it was the sudden
    stop at the end of the fall...no, it was the fact that not all parts of
    him decelerated together equally that caused tearing of
    Components mounted above board (not flush mounted) are supposed to have
    (in many cases) their leads bent to absorb the repeated stress (and
    hence fatigue) that thermal cycling would otherwise produce. We're
    talking about quality products here and so it may not really matter if
    the device is always on or cycled. I am merely pointing out that the
    thermal fatigue scenario is real and not imagined (and yes, it applies
    to radios and televisions too - not too sure about the light bulbs
    though. :)
    You can interpret the silence any way that soothes your ego, but it is
    often the case that other may tire of attempting to educate some peeps.
    Right - if it failed - it was broken. :eek:\
    Power switches are designed to operate through thousands of
    repetitions - but they will eventually wear out. The more you use them
    the more wear they get. Same goes for relay contacts. Repetitive stress
    disorders like carpal tunnel syndrome aren't caused by repetitive
    stress - they are design flaws. :)
    The "wear" part of "normal wear and tear" is increased on some
    components by this - while other components may see decreased wear by
    it. Overall, it probably doesn't matter either way in most high quality
    modern computers.
    Roger Wilco, Feb 18, 2005
  18. Thomas G. Marshall

    Roger Wilco Guest

    Thermal fuses are designed to open (fail?) when a current results in a
    certain temperature melting the link or increasing the tension
    (slow-blow) to the point of breakage. The "failure" of the fuse is what
    prevents the possible failure of the circuit the fuse delivered the load
    current to. So - yes heat (actually temperature) does cause failure.
    No, the failure was BY design and worked flawlessly (the fuse failed at
    the temperature it was designed to fail at). They could have just as
    easily forgot that a slow blow type of fuse was needed to allow the
    surge of initial powerup to not result in the requisite temperature
    being reached to soon (allow transient temperature overages while
    persistent overages cause failure). Back on point - many slow blow fuses
    have a "heater" element and a bi-metal strip that when heated to a
    certain temperature increases tension to the point of failure (but not
    instantaneously) - after repeated cycling the bi-metal strip becomes
    fatigued and a lack of failure results. Luckily there is usually an
    instantaneous fuse link that fails at a slightly higher temp also
    incorporated as failsafe. You've probably seen these - thin metal strip,
    a bead, a bi-metal coiled strip all in one package.
    Yes, I do see what you are saying and it is not incorrect in my
    assessment (considering we are not talking theory but practice). I have
    been involved in the electronics industry for many years and you will
    not convince me that thermal expansion/contraction problems are a thing
    of the past only.
    Steps have been taken to reduce the effect of fatigue on MTBF, that does
    not mean it doesn't exist. It might not be an important consideration
    for a complex electro-mechanical device that has other issues related to
    "always on" wear.
    I never suggested such a thing, I countered your insistence that it is a
    myth. I made no claims about any "always-on" scenario being better or
    worse for any individual components. Your car suffers more wear during
    startup than most any other time - that does not mean I suggest leaving
    it running all night in the garage. If you said the car startup wear was
    a myth then I would counter point.
    It was just one example of expansion/contraction wear. Mounting screws,
    plugs & sockets, heatsinks, risers - many things are affected by this
    motion and we have yet to design them completely out.
    What is this fixation you have for components? It is what is in-between
    these components (what connects them) that is most affected. A physical
    trait of dissimilar materials is that they expand and contract with
    temperature with differing amounts even though they are physically
    connected (and often rigidly).
    Roger Wilco, Feb 18, 2005
  19. Thomas G. Marshall

    Sparky Guest

    You omitted: "He was dead when I got here - I was just going thru his
    pockets looking for loose change".
    Sparky, Feb 18, 2005
  20. Thomas G. Marshall

    Sparky Guest

    You're still trying to follow this???

    Sparky, Feb 18, 2005
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