General PC question

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Golden Oldie

Not really sure which group to ask this so picked this one! Anyway, is it
safe to leave my pc on overnight? If so what effect would this have on
electricity bills?
 
Golden said:
Not really sure which group to ask this so picked this one! Anyway, is it
safe to leave my pc on overnight? If so what effect would this have on
electricity bills?
Click to expand...

Usually nothing should happen and the additional electricity costs
would also be minimal. Having written this, one should also take heed
in having a very stable mains power supply along with the computer and
key peripherals sitting behind a real UPS (i.e., none of those upgraded
surge protectors), and also that normal security and backup protections
have been undertaken.
 
Most PCs have onboard fusing in the motherboard and power supply.
Safety is not really an issue.


Varies by make/model on power consumption. Also varies if the PC is
actually on, in standby, or hibernating.

A PC also contributes to the AC bill as it creates heat. The amount of
heat is in lieu of same as above.

The obvious solution to all 3 potentials is simply to turn the PC off
when not in use.
Click to expand...

Thanks guys.
 
Golden said:
Not really sure which group to ask this so picked this one! Anyway, is it
safe to leave my pc on overnight? If so what effect would this have on
electricity bills?
Click to expand...

Safety, part I: A PC, like any other electrical appliance, is a fire
hazard; leaving it on overnight will incur some risk of fire. In my
opinion, the risk is very low; I have eight PCs in my home, and I almost
never turn them off.

Safety, part II: There is a long-running argument about whether it is
more harmful to the PC to leave it on overnight or to turn if on every
morning and off every night. The basis of the argument is the potential
for wear-out v. the thermal shock due to turning on a cold PC; the
primary wear-out concern is the mechanical hard drive(s), while every
component is subject to thermal shock. The argument is interesting
(and I know which side I'm on), but most PCs will be replaced by a
newer/faster unit before they die from any hardware cause.

Electricity: A PC is an electrical appliance (some wise person said so).
A pretty well-equipped home PC might draw 1 KW when running a heavy
workload, while a more vanilla home PC might draw 0.5 KW running the
same workload. But home PCs are pretty green, and most components
slip automatically into some reduced-power mode when they can.

Peripheral devices connected to a PC can use more power than the PC
itself. A CRT monitor might use 100-150W when active, but ~5W in
standby; a LED monitor might use 75-100W when active, but ~5W when
in standby. A hard drive might use 10-15W when in use, but ~5W when
idle. A laser printer might use 250-500W when printing, but ~5W when idle.
Most external SOHO comm.gear (routers, switches, hubs, modems, etc.) is
very low power; roughly equal to a couple of night lights per device.

Order of magnitude, a PC with peripherals might be 1KW in the daytime and
250W at night; at 10 cents per KWH, leaving it on (but idle) from 6pm to
6am wastes 30 cents. (Standard caveat: YMMV = Your Mileage May Vary.)
 
Golden Oldie said:
Not really sure which group to ask this so picked this one! Anyway, is it
safe to leave my pc on overnight?
Click to expand...

Most PCs have onboard fusing in the motherboard and power supply. Safety is
not really an issue.
If so what effect would this have on
electricity bills?
Click to expand...

Varies by make/model on power consumption. Also varies if the PC is
actually on, in standby, or hibernating.

A PC also contributes to the AC bill as it creates heat. The amount of heat
is in lieu of same as above.

The obvious solution to all 3 potentials is simply to turn the PC off when
not in use.
 
Today, Golden Oldie made these interesting comments ...
Not really sure which group to ask this so picked this one!
Anyway, is it safe to leave my pc on overnight? If so what
effect would this have on electricity bills?
Click to expand...
Safe? Definitely. There's a lot of debate on what is harder on your
hardware running 24x7 as I do or shutting it down everynight. I
personally don't shut mine down unless 1) I am going away, 2) we
are having local power problems my APC UPS can't handle, or 3) some
update forces me to restart. I DO shut my Samsung 21" LCD monitor
down when I'm not using it, as there's only so many hours worth in
this technology before dead pixels start appearing. I've had mine
about 2 years now and have maybe 15 or so black spots; don't know
if my shutting it down helps or hurts.

As to the power usage, the big guy is your monitor, of course.
Depending on how much electricity costs for you locally, the amount
you may save could be substantial - several hundred dollars/year -
or might be minimal. Or, if you think green, then shutting down may
help the global warming thingy.

Why not see for yourself? Run your PC, monitor, printer on,
anything else associated with your PC and look at the speed the
dial or digital readout is moving on your electrical meter. Then,
shut everything down and measure again. Do the test for some
reasonable period when nothing else is running in your house, say
30-60 minutes, then try extrapolating to see how much energy you
might save.
 
Today, Dave made these interesting comments ...
Most PCs have onboard fusing in the motherboard and power
supply. Safety is not really an issue.
Click to expand...

Safety is more than the mobo, such as getting a series of
brownouts or blackouts of short duration followed by a voltage
spike when the power comes back on. I get several of these/month
where I live, usually less than 1/2 second in duration. So, I
have an APC UPS guarding my PC and external HD against short-term
hits. Also, I have had a couple of really bad experiences when
doing a major disc write when our power went down suddenly. One
of these was doing a partition resize and required me to nuke the
HD and reinstall everything.

How much safety is safe is as much determined by the quality or
lack thereof of the power company that supplies you as it does
today's modern safeguards built into our HW. Each person has to
evaluate the risks themselves, there is no one right answer.
Varies by make/model on power consumption. Also varies if the
PC is actually on, in standby, or hibernating.

A PC also contributes to the AC bill as it creates heat. The
amount of heat is in lieu of same as above.
Click to expand...

Yep, sure do! Mine has 5, count 'em, 5 fans running and a lot of
heat blows out the case. But, as I said in an earlier reply, I do
shut down my monitor both to save the LCD pixels and to save on
juice and reduce the heat load in my office. Winter isn't a
problem but with only one output duct in the room, it can get
pretty hot during A/C season, especially since the window faces
west (for that, I installed a room darkening shade).
 
Today, Bob Willard made these interesting comments ...
Safety, part I: A PC, like any other electrical appliance, is
a fire hazard; leaving it on overnight will incur some risk of
fire. In my opinion, the risk is very low; I have eight PCs
in my home, and I almost never turn them off.
Click to expand...

compared to "normal" electrical appliances, a PC is a very low
amperage device so I would expect the fire hazard to be
comensurately very low in agreement with your experience
Safety, part II: There is a long-running argument about
whether it is more harmful to the PC to leave it on overnight
or to turn if on every morning and off every night. The basis
of the argument is the potential for wear-out v. the thermal
shock due to turning on a cold PC; the primary wear-out
concern is the mechanical hard drive(s), while every component
is subject to thermal shock. The argument is interesting (and
I know which side I'm on), but most PCs will be replaced by a
newer/faster unit before they die from any hardware cause.
Click to expand...

sure is! after I finally got rid of Win 95 and 98 and went to XP
on both my PCs, they are finally stable enough to just let them
run. unless something like an update of Windows forces a restart,
I seldom reboot more than once a month, I just let 'er run!
Electricity: A PC is an electrical appliance (some wise
person said so). A pretty well-equipped home PC might draw 1
KW when running a heavy workload, while a more vanilla home PC
might draw 0.5 KW running the same workload. But home PCs are
pretty green, and most components slip automatically into some
reduced-power mode when they can.
Click to expand...

this is analagous to the silly arguments that low volume toilets
save a lot of water. I agree with you on the likely power
amounts, which are really negligible compared to when your wife
runs her appliances or the furnace or A/C comes on, not to
mention all those TVs on with every light in the place burning
all night.
Peripheral devices connected to a PC can use more power than
the PC itself. A CRT monitor might use 100-150W when active,
but ~5W in standby; a LED monitor might use 75-100W when
active, but ~5W when in standby. A hard drive might use
10-15W when in use, but ~5W when idle. A laser printer might
use 250-500W when printing, but ~5W when idle. Most external
SOHO comm.gear (routers, switches, hubs, modems, etc.) is very
low power; roughly equal to a couple of night lights per
device.

Order of magnitude, a PC with peripherals might be 1KW in the
daytime and 250W at night; at 10 cents per KWH, leaving it on
(but idle) from 6pm to 6am wastes 30 cents. (Standard caveat:
YMMV = Your Mileage May Vary.)
Click to expand...

I like "all other factors being equal, but they seldom are". if
the OP is ultra concerned, the only real way to satisfy their
curiousity is to run some carefully controlled tests.
 
Golden Oldie said:
Not really sure which group to ask this so picked this one! Anyway, is it
safe to leave my pc on overnight? If so what effect would this have on
electricity bills?
Click to expand...
 
Actually, it is a great question that bothers many (myself included) from
time to time.

Here is an interesting article to share: Do you need to turn off your PC at
night?

http://www.microsoft.com/smallbusin...you_need_to_turn_off_your_pc_at_night.mspxFor myself, if I know that I am done for the day, I will turn it off. If Ihave any doubt, I leave it on. But as anything else, it doesn't always workas expected.Hope this helps and good luck."Golden Oldie" <[email protected]> wrote in messageNot really sure which group to ask this so picked this one! Anyway, is it> safe to leave my pc on overnight? If so what effect would this have on> electricity bills?
 
Not really sure which group to ask this so picked this one! Anyway, is it
safe to leave my pc on overnight? If so what effect would this have on
electricity bills?
Click to expand...

Guess what? You post doesn't belong here, at least not in the context
that you are asking it under.

Try Google. This has been discussed to death; you'll find all the
discussion you could ever want. Try doing your OWN research!
 
Golden said:
Not really sure which group to ask this so picked this one! Anyway,
is it safe to leave my pc on overnight? If so what effect would this
have on electricity bills?
Click to expand...

I never shut my computer down only the monitor. Another thing my place of
employment is a 24/7 operation and the computers have been turned on for
years with no problems.
 
Bob Willard said:
Safety, part II: There is a long-running argument about whether it is
more harmful to the PC to leave it on overnight or to turn if on every
morning and off every night. The basis of the argument is the potential
for wear-out v. the thermal shock due to turning on a cold PC; the
primary wear-out concern is the mechanical hard drive(s), while every
component is subject to thermal shock. The argument is interesting
(and I know which side I'm on), but most PCs will be replaced by a
newer/faster unit before they die from any hardware cause.
Click to expand...

The above is a twisted effort of making a non-safety thing, appear as a
safety issue. Its not related to safety. Its an argument about longevity
and service life. 2 different animals, not remotely related in any fashion,
shape, or form.
 
housetrained said:
On what tests (if any) did you deduce these answers?
Click to expand...

I used an AC voltmeter and an AC ammeter to measure power use
on a handful of PCs and peripherals in my house. And, I read
some vendor's specs.

There is, of course, a fairly wide range of power use for a
single class of devices. YMMV.
 
Bob Willard said:
Safety, part I: A PC, like any other electrical appliance, is a fire
hazard -
Click to expand...
Safety, part II: There is a long-running argument about whether it is
more harmful to the PC to leave it on overnight or to turn if on -
Click to expand...
Electricity: A PC is an electrical appliance (some wise person said so).
A pretty well-equipped home PC might draw 1 KW when running a heavy -
Click to expand...

I agree with your assessments, they are valid, however do I believe my
conclusion to all three of them are different from yours (as you wrote: There
is a long-standing argument about -). I personally have connected the PC,
monitor, printer and router to AC by an extension cord with multiple outlets
and a mains switch, and turn it off when the "appliances" are in their power
saving modes. For safety reason: I just don’t like power supplies when they
do not behave. With regards to power consumption: It doesn’t hurt Golden
Oldies electricity bills a lot to leave the PC and associated equipment on
overnight, however when you add your well estimated power consumptions and
multiply it by some millions of PCs around the world – then -. But THAT is a
discussion for another forum. Should Al Gore be addressed for picking up the
issue?

Regards,
Ka2H
 
Bob said:
I used an AC voltmeter and an AC ammeter to measure power use
on a handful of PCs and peripherals in my house. And, I read
some vendor's specs.

There is, of course, a fairly wide range of power use for a
single class of devices. YMMV.
Click to expand...

One thing I noticed with my ammeter, is it did not do a very
accurate reading while the computer was sleeping. A sleeping
computer should draw somewhere between 10W and 20W, and my
ammeter gave readings consistent with a much higher wattage.
Just a FYI that working at the A.C. cord in that case, can lead
you to a wrong conclusion about the power. For a sleeping
computer, it might be better to use a clamp-on DC ammeter
and measure the current flowing in the main 20 wire ATX power
cable. There should only be current flow in +5VSB in that
case. (You could assume the PSU is only 50% efficient, and
multiply the DC consumption by a factor of 2, to get an
upper bound on the AC consumption. The PSU is less efficient
for the +5VSB, than for the main outputs.) I suspect the A.C.
current waveform on the cord, is not a pure sine wave, when the
computer sleeps. And a digital meter might have more trouble
with it than an analog one. It is even possible that the
"Kill-a-watt" meter suffers from the same problem (inaccurate
when measuring a sleeping computer).

Paul
 
Paul said:
One thing I noticed with my ammeter, is it did not do a very
accurate reading while the computer was sleeping. A sleeping
computer should draw somewhere between 10W and 20W, and my
ammeter gave readings consistent with a much higher wattage.
Just a FYI that working at the A.C. cord in that case, can lead
you to a wrong conclusion about the power. For a sleeping
computer, it might be better to use a clamp-on DC ammeter
and measure the current flowing in the main 20 wire ATX power
cable. There should only be current flow in +5VSB in that
case. (You could assume the PSU is only 50% efficient, and
multiply the DC consumption by a factor of 2, to get an
upper bound on the AC consumption. The PSU is less efficient
for the +5VSB, than for the main outputs.) I suspect the A.C.
current waveform on the cord, is not a pure sine wave, when the
computer sleeps. And a digital meter might have more trouble
with it than an analog one. It is even possible that the
"Kill-a-watt" meter suffers from the same problem (inaccurate
when measuring a sleeping computer).

Paul
Click to expand...

Your assumption is based on approximate wattage use 10-20W. That may be
invalid, although commonly published as such.
 
Dave said:
Your assumption is based on approximate wattage use 10-20W. That may be
invalid, although commonly published as such.
Click to expand...

Check the +5VSB rating on the side of the supply. It is limited
to 2 amps. That means 10W max from the supply. At 50% efficiency,
the max drawn from the wall, is 20W. It should be a little bit
less than that 20W number. At least some motherboard manuals,
give hints as to how much current is needed during sleep. So
that is how I arrived at the 10W-20W estimate.

Paul
 
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