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

[Thomas G. Marshall]

(e-mail address removed) coughed up:

....[rip]...

The development systems I mentioned were left on all the time because
they were in use all the time running real development work round the
clock. I was one of the people using them. The admin machines were
switched off when they were not required. That was every night, all
night. It's not a random sample of systems. These are two sets of
machines. The admin systems are in the office environment, with almost
no regular maintenance. The development systems are in large computer
rooms and share the mainframe environment to some extent. They are
also kept clean, that may explain some of the differences.

I find your observations to be fascinating. Would you add some to this?

1. How many machines in each group (roughly), at any given time?

2. What precisely are the difference in the two environments? I mean:

a. are the ambient temperatures different?
b. are some on the cleaner power of ups's and the like?
c. does anyone big and hairy hit them with their fists?

Thanks

 

[Conor]

The computer left on 24/7 was finally shut off. Then it
would not power up. This computer was now considered failed
due to being 'power cycled'. But it should have remained a
prime example of why 24/7 is so destructive. In the meantime,
once we first made the distinction, then suddenly computers
left on 24/7 were failing more often.

What a crock of red herring shit. This happens with most stuff because
of things like capacitor failure in PSUs. Its not noticed until its
turned off then won't power up. Big deal. If the cost of a new £15 PSU
is a problem you can't afford a PC in the first place.

 

[Conor]

24/7 operation provides nothing significant to system
reliability, causes increased component wear, and consumes
electricity to no purpose. Wear from hours of operation is
significant on the parts that fail most often. Power up does
not cause wear despite the many myths to the contrary.

Bullshit. Ever heard of thermal creep?

 

[Conor]

I've been doing computers and aerospace electronics for too
many decades to fall for these well promoted myths about 24/7
operation, heat, and dust created problems. Too many years
and too much asking questions at the electronic component
level.

Shame you learnt jack shit then.

Too many years
and too much asking questions at the electronic component
level.

You mean questions like.."Whats that round thing?"

 

[steve]

(e-mail address removed) coughed up:

...[rip]...

The development systems I mentioned were left on all the time because
they were in use all the time running real development work round the
clock. I was one of the people using them. The admin machines were
switched off when they were not required. That was every night, all
night. It's not a random sample of systems. These are two sets of
machines. The admin systems are in the office environment, with almost
no regular maintenance. The development systems are in large computer
rooms and share the mainframe environment to some extent. They are
also kept clean, that may explain some of the differences.

I find your observations to be fascinating. Would you add some to this?

1. How many machines in each group (roughly), at any given time?

About 2000 in the development group. All the rest in the company I
call admin. That's every other computer in a big company - about
15,000 people and most had a computer.

2. What precisely are the difference in the two environments? I mean:

a. are the ambient temperatures different?

Admin. Normal office environment. 65 to 75F most areas air
conditioned.

Most of the development systems were in computer rooms. 70F all air
conditioned.

b. are some on the cleaner power of ups's and the like?

Not sure what that means. If you mean power outs, they are very rare.

c. does anyone big and hairy hit them with their fists?

Only when something goes wrong!

 

[Dave Budd]

You could write a bit of VB script to do the scan and then shut down the
computer when it has finished.

....or you could use a computer language, like Python.

 

[Ben Myers]

Puhleeeze! Does this have to be such an emotional issue as to inspire(?)
insulting language? ... Ben Myers

 

[Thomas G. Marshall]

(e-mail address removed) coughed up:

(e-mail address removed) coughed up:

...[rip]...

The development systems I mentioned were left on all the time
because they were in use all the time running real development work
round the clock. I was one of the people using them. The admin
machines were switched off when they were not required. That was
every night, all night. It's not a random sample of systems. These
are two sets of machines. The admin systems are in the office
environment, with almost no regular maintenance. The development
systems are in large computer rooms and share the mainframe
environment to some extent. They are also kept clean, that may
explain some of the differences.

I find your observations to be fascinating. Would you add some to
this?

1. How many machines in each group (roughly), at any given time?

About 2000 in the development group. All the rest in the company I
call admin. That's every other computer in a big company - about
15,000 people and most had a computer.

2. What precisely are the difference in the two environments? I
mean:

a. are the ambient temperatures different?

Admin. Normal office environment. 65 to 75F most areas air
conditioned.

Most of the development systems were in computer rooms. 70F all air
conditioned.

b. are some on the cleaner power of ups's and the like?

Not sure what that means. If you mean power outs, they are very rare.

IIRC, UPS's (not to spark off another debate) are known for straightening
out power surges, small spikes, and other non-conforming anti-sine-waves.
I'm guessing that a cleaner signal as such would less approximate
jump-discontinuities in the wave form, harsh slopes, etc., that might change
the wear and tear on the equipment. All educated guessing, but from my
engineering background.

Only when something goes wrong!

Rules me out then Good think I'm not part of the sampling...... I hit
machines for the heck of it....

 

[Thomas G. Marshall]

Conor coughed up:

What a crock of red herring shit. This happens with most stuff because
of things like capacitor failure in PSUs. Its not noticed until its
turned off then won't power up. Big deal. If the cost of a new £15 PSU
is a problem you can't afford a PC in the first place.

Conor, you seem to be very educated. You seemed armed to the teeth with
counter information, which is certainly not a failing. However, if you take
the teeth out of your end of the conversation you'll much more soundly
defeat your adversary, without fail, every time.

 

[Thomas G. Marshall]

Dave Budd coughed up:

...or you could use a computer language, like Python.

{gack} . Explanation: I was using Python in the ugly very early days
when it barely worked. I had to write loops and control code in specific
ways to avoid known bugs. I'm sure it's solid by now, but I was using it in
the days when things were rotten, and I'm still feeling the emotional
scarring...

 

[Dave Budd]

{gack} . Explanation: I was using Python in the ugly very early days
when it barely worked. I had to write loops and control code in specific
ways to avoid known bugs. I'm sure it's solid by now, but I was using it in
the days when things were rotten, and I'm still feeling the emotional
scarring...

;->
I bet you'd still rather do that than write VBscript, though.
I know I would

 

[w_tom]

Look for the let-through voltage on UPSes. 120 VAC plug-in
UPSes typically ignore all surges and noise until that voltage
exceeds 330 volts. It does nothing for harmonic problems. IOW
it does not "straightening out power surges, small spikes, and
other
non-conforming anti-sine-waves." Furthermore it only claims
protection from one, typically irrelevant, type of transient.

Most plug-in UPSes output greatest noise and spikes when in
battery backup mode. This UPS, unloaded in battery backup
mode, outputs two 200 volt square waves with a 270 volt spike
between those square waves. When not in battery backup mode,
harmonics from AC mains connect directly through the UPS.
Plug-in UPSes short the consumer of facts so that a consumer
will *assume* it protects from all types of transients.

All are encouraged to verify this UPS output power on an
oscilloscope. That 200 volt square wave is called a modified
sine wave - so that you hope it outputs cleaner power. Yes a
square wave composed of sine waves - of many frequencies which
therefore makes the power 'dirtier'.

To get the 'cleaner' power from a plug-in UPS, that UPS
would cost $500+ retail list. Such clean power is not found
in $100 plug-in UPSes. But then power supply specs as even
demanded by Intel makes this worry about 'cleaner' power
irrelevant. Power supplies are why computer grade UPSes can
output such 'dirty' power. Computer grade UPS output is so
'dirty' that it may even damage some samll electric motors.

 

[steve]

(e-mail address removed) coughed up:

IIRC, UPS's (not to spark off another debate) are known for straightening
out power surges, small spikes, and other non-conforming anti-sine-waves.
I'm guessing that a cleaner signal as such would less approximate
jump-discontinuities in the wave form, harsh slopes, etc., that might change
the wear and tear on the equipment. All educated guessing, but from my
engineering background.

Ah! UPS. I read it as ups's as in ups and downs. I assumed you were
talking about supply fluctuations.

We don't need UPS. All the computer rooms and most of the offices are
on very stable supplies. Mean time between fails is years. Even the
domestic supply that my home PCs are on hardly ever fails. I can only
remember one fail in the last few years.

 

[Ernie B.]

Look for the let-through voltage on UPSes. 120 VAC plug-in
UPSes typically ignore all surges and noise until that voltage
exceeds 330 volts. It does nothing for harmonic problems. IOW
it does not "straightening out power surges, small spikes, and
other
non-conforming anti-sine-waves." Furthermore it only claims
protection from one, typically irrelevant, type of transient.

Probably mostly true, although it's no trick at all to use a low-pass
filter to deal with the higher harmonics.

Most plug-in UPSes output greatest noise and spikes when in
battery backup mode. This UPS, unloaded in battery backup
mode, outputs two 200 volt square waves with a 270 volt spike
between those square waves. When not in battery backup mode,
harmonics from AC mains connect directly through the UPS.
Plug-in UPSes short the consumer of facts so that a consumer
will *assume* it protects from all types of transients.

It doesn't, which is the reason to have the UPS feed a surge
suppressor, usually a box of transorbs, with the output of the
suppressor feeding the computer system. Keep in mind that the
purpose of a UPS is to allow an orderly system shut down when
everything else goes dark.
<snip>

 

[Ben Myers]

Ah, you're lucky. Out here in the remote wilds of Central Massachusetts, not 30
miles from the metropolis of Boston, power outages, drops, and surges are all
too frequent, even within industrial complexes. UPS equipment is a necessity
for one who cares about the reliability of ones computers and the continued
availability of ones data.

Together with the crumbling highways and aging decrepit railroads, I guess this
means that the U.S. infrastructure is falling apart even as we now speak. Or
maybe it was never as good as we all thought it was? ... Ben Myers

 

[Ogden Johnson III]

[Prior exchanges involved in UPS misunderstanding snipped.]

Ah, you're lucky. Out here in the remote wilds of Central Massachusetts, not 30
miles from the metropolis of Boston, power outages, drops, and surges are all
too frequent, even within industrial complexes. UPS equipment is a necessity
for one who cares about the reliability of ones computers and the continued
availability of ones data.

Indeed he is, Ben. Virginia Power gets their hamsters from the
lowest bidder. On a just-in-time basis. Which those poor,
starved, weakling hamsters never make. So even in a *good*
month, we see at least one or two power drops. Don't even ask
about winter - particularly since we aren't out of it yet. :-(

 

[w_tom]

As other have demonstrated, the purpose of a plug-in UPS is
to protect data from blackouts and extreme brownouts. Other
functions sometimes used to recommend a UPS must already be
solved elsewhere - such as inside a computer's power supply.

For example, if AC line voltage dips so low that
incandescent bulbs are at 40% intensity, then the computer
power must still provide sufficient power to a fully loaded
computer. This is even demanded by Intel specs. Ae UPS would
be for brownouts that are more extreme.

For example, a line filter was recommended for harmonics.
Why? First any properly constructed power supply (which does
not include some clone computers) contains an AC line filter.
Furthermore, the harmonics that one may worry about could be
destructive to some small electric motors. But harmonics must
not adversely affect a computer's power supply. A computer
grade UPSes can output so many powerful harmonics that a
modified sine wave is a 200 volt square wave. And still those
harmonics must be irrelevant to any minimally sufficient
computer.

For example, UPS manufacturers recommend no protector on
UPS outputs. Why? Again, that output waveform when in
battery backup mode. Either the UPS can be damaged or the
protector is degraded quickly. Either way, UPS manufacturers
(quietly) recommend no protectors on UPS outputs. But again,
why would one waste good money on that very expensive plug-in
protector when the same circuit is already inside a UPS's AC
power input? Furthermore, anything that will provide
sufficient protection at that computer must already be inside
that computer. Some clone computers are missing such
essential functions which is but another reason for buying a
properly constructed machine (rather than trying to save
pennies).

Above three examples to increase computer reliability are
not recommended for technical reasons. In each case, a
computer (such as the Dell) meets industry standard and Intel
specifications making those 'solutions' unnecessary. Again,
some clone computers are missing essential functions which may
be why some then recommend unnecessary devices such as
protectors or low pass filters.

 

[Roger Wilco]

Power up does not cause wear despite the many myths to the contrary.

Power up (or more accurately heat-up cool-down) causes wear to what
would otherwise be considered non-moving parts. It is no myth that
things expand with increased temperature and contract with decreased
temperature.

Electric motor circuitry experiences an amperage surge during spinup
that is above its normal operating amperage because the motor has not
yet created a sufficient back-voltage to counter the applied voltage.
Most mechanical devices are designed to operate within a certain range
of temperatures, and at power-up time it may be outside of that
specification.

I'm sure that well designed computers will suffer little ill effects
from either scenario - but that does not mean power-up wear is a myth.

 

[User N]

User N coughed up:

You seem to want a "AV" scans to be performed every day.
Specifically, what "AV" software are you referring to? Is it
something that lacks the ability to automatically scan on an as
needed basis? For example, when the filesystem opens [or
closes] files?

As I said in the original post, it is NAV2003.

Oh, so that is the only thing you'll be scanning with on a daily
basis? If so, I'd be interested to know why you feel it is
necessary to perform full NAV2003 scans every day.

 

[w_tom]

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
reasoning.

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
environment.

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.