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Computer power usage
|
|
| Robert Morein 2005-10-17, 12:21 pm |
| I used a Kill A Watt to analyze my setup. There were some surprises:
1. Modern 21" Sony based WEGA monitors use only 80 watts a 1600x1200, 60Hz.
This isn't much more than a flat panel.
2. CyberPower 1500VA UPSes measured at 30 watts no load, fully charged. It
was quite a disappointment that they are such power hogs. Is there anything
more efficient in this power range?
3. Cable modem, routers, firewalls, VoIP appliance, fiber optic links
totaled around 80 watts.
4. A Dual Athlon with an Nvidia 5900 came in at a mere 225 watts while
running in 2D mode. PS is a 600W PF neutralized Silenx, which is made by
Fortron.
5. A P4 2.6/400 with an Nvidia 5200 came in at 150 watts, in 2D mode. Supply
is a less efficient 400W Computer Warehouse, not PF neutralized, probably
also made by Fortron.
6. A Via C3 low power machine, which I constructed using a Supermicro socket
370 mb, for use as an email/text processing always-on machine, was a bit
disappointing. In spite of the fact that this processor idles at just a
couple watts, total power draw was 100 watts. Video card is a fanless 2D
only Matrox G550. Power supply is a PF neutralized Silenx 350 watt unit.
Where is all the power going?
Total power draw with just the Via machine two 21" monitors is 383 watts. I
can knock off 80 watts by turning off one of the monitors, but the total is
still disappointing.
Comments?
| |
|
| On 2005-10-17, Robert Morein <nowhere@nowhere.com> wrote:
> I used a Kill A Watt to analyze my setup. There were some surprises:
>
> 1. Modern 21" Sony based WEGA monitors use only 80 watts a 1600x1200, 60Hz.
> This isn't much more than a flat panel.
> 6. A Via C3 low power machine, which I constructed using a Supermicro socket
> 370 mb, for use as an email/text processing always-on machine, was a bit
> disappointing. In spite of the fact that this processor idles at just a
> couple watts, total power draw was 100 watts. Video card is a fanless 2D
> only Matrox G550. Power supply is a PF neutralized Silenx 350 watt unit.
> Where is all the power going?
>
> Total power draw with just the Via machine two 21" monitors is 383 watts. I
> can knock off 80 watts by turning off one of the monitors, but the total is
> still disappointing.
>
> Comments?
>
>
Found the same with my C3 integrated board (1-Gigapro); used far more power
than I expected it to.
The best consumption I've found is from an IBM Thinkpad 560, P100, DSTN,
no optical or floppy drive: in normal use, runs between 11 and 20 watts
(19 - 30 Volt-Amps). It works well for basic tasks.
You may want to measure your computers again, but set your Kill-A-Watt
meter to Volt-Amps instead of Watts. The true power consumption of electronic
equipment doesn't measure well with the "Watts" setting. For instance, I have
a 19" NEC CRT, which comes in between 60-90 watts, but the VA measurement
shows an average of about 150VA. Quite a difference. The watt measurement
works well for things like lights and coils, but VA is better for things like
computers and stereos.
--
Solar-powered Linux: Slackware 10.0, 2.6.13, Averatec 3250H1 w/accel S3Uni
RLU#272755
| |
| tkgoogle@ktcnslt.com 2005-10-17, 3:21 pm |
| Robert Morein wrote:
> I used a Kill A Watt to analyze my setup. There were some surprises:
>
> 1. Modern 21" Sony based WEGA monitors use only 80 watts a 1600x1200, 60Hz.
> This isn't much more than a flat panel.
For CRT's, try measuring the power consumption while displaying an
white screen. (or just set screen background color to white.) Don't
be surprised if power consumption increases by 50% or more.
A 21.3" Samsung 213t LCD monitor (1600x1200) consumes about 38 watts.
> 2. CyberPower 1500VA UPSes measured at 30 watts no load, fully charged. It
> was quite a disappointment that they are such power hogs. Is there anything
> more efficient in this power range?
Multiple UPS's are a big consumer of energy. Consider using a single
larger standby UPS, the energy savings can be significant.
Consider something really big, but not TOO big, like a Tripp-lite
Power verter.. APS-912 .. APS-1012. They have quick switching times and
function just like a big UPS. Connect them up to a Group-27 Deep cycle
Trolling Bat and you'll have enough standby power to run ALL your PC's
for hour or two.
During float/standby operation a APS-912 power consumes ~13 watts.
> 3. Cable modem, routers, firewalls, VoIP appliance, fiber optic links
> totaled around 80 watts.
How did you measure power consumption fibre optic links??
Careful selection of replacements can save considerable amounts of
energy. For example.. my newly purchased linux based Actiontec DSL
modem/firewall/router/4port hub consumes far less power than the
components it replaced. (~5 watts verses ~13 watts).
Likewise.. a modern Dlink DSS-16+ (16 port Enet-switch ~3 watts)
draws a fraction of the power needed by some of my older ethernet hubs
and switches.
> 4. A Dual Athlon with an Nvidia 5900 came in at a mere 225 watts while
> running in 2D mode. PS is a 600W PF neutralized Silenx, which is made by
> Fortron.
What's the idle consumption? (which OS's are you using?)
NT & ?W2K? are not known for activating CPU power saving function
when running MP kernel.
> 5. A P4 2.6/400 with an Nvidia 5200 came in at 150 watts, in 2D mode. Supply
> is a less efficient 400W Computer Warehouse, not PF neutralized, probably
> also made by Fortron.
Same questions as those for item 4.
> 6. A Via C3 low power machine, which I constructed using a Supermicro socket
> 370 mb, for use as an email/text processing always-on machine, was a bit
> disappointing. In spite of the fact that this processor idles at just a
> couple watts, total power draw was 100 watts. Video card is a fanless 2D
> only Matrox G550. Power supply is a PF neutralized Silenx 350 watt unit.
> Where is all the power going?
100Watts seams a bit on the high side.. What is the OS? how many
other un-needed components are plugged in and powered up.. Floppy?,
CD?, DVD?, -R's, disks?, etc..
Older desktop OS's 95,98,ME don't activate the power saving
function of CPU..
Get one of the well known Halt/Idle programs PC's running older OS's..
http://www.benchtest.com/coolarch.html (several are free)..
As a reference.. I getting ready to phase in a recycled 1U firewall
as my new email/ftp/web server.. it's based on AMD K6-2 300 mhz.. 1
disk.. no video or other components and consumes about 18 watts.
>
> Total power draw with just the Via machine two 21" monitors is 383 watts. I
> can knock off 80 watts by turning off one of the monitors, but the total is
> still disappointing.
>
> Comments?
Lastly.. Shutoff screen savers which constantly draw patterns on
display, those unnessary features consume considerable power. Just set
screen saver to blank or none and adjust monitor standby options.
| |
| Ulysses 2005-10-17, 4:21 pm |
|
"Robert Morein" <nowhere@nowhere.com> wrote in message
news:8vOdncVfIZQtIM7eRVn-sQ@giganews.com...
> I used a Kill A Watt to analyze my setup. There were some surprises:
>
> 1. Modern 21" Sony based WEGA monitors use only 80 watts a 1600x1200,
60Hz.
> This isn't much more than a flat panel.
> 2. CyberPower 1500VA UPSes measured at 30 watts no load, fully charged. It
> was quite a disappointment that they are such power hogs. Is there
anything
> more efficient in this power range?
> 3. Cable modem, routers, firewalls, VoIP appliance, fiber optic links
> totaled around 80 watts.
> 4. A Dual Athlon with an Nvidia 5900 came in at a mere 225 watts while
> running in 2D mode. PS is a 600W PF neutralized Silenx, which is made by
> Fortron.
> 5. A P4 2.6/400 with an Nvidia 5200 came in at 150 watts, in 2D mode.
Supply
> is a less efficient 400W Computer Warehouse, not PF neutralized, probably
> also made by Fortron.
> 6. A Via C3 low power machine, which I constructed using a Supermicro
socket
> 370 mb, for use as an email/text processing always-on machine, was a bit
> disappointing. In spite of the fact that this processor idles at just a
> couple watts, total power draw was 100 watts. Video card is a fanless 2D
> only Matrox G550. Power supply is a PF neutralized Silenx 350 watt unit.
> Where is all the power going?
>
> Total power draw with just the Via machine two 21" monitors is 383 watts.
I
> can knock off 80 watts by turning off one of the monitors, but the total
is
> still disappointing.
>
> Comments?
>
>
Are you running a small country or something? I don't even know what most
of the stuff is that you are talking about. What do you use it for?
BTW, just to stay on topic, my computer uses about 95 watts--2.4G Desktop
with a 15" LCD monitor. This is according to my Vector inverter with
built-in watt meter so it may not be real accurate. Turning on the inkjet
printer makes it jump to 105 watts.
| |
| Robert Morein 2005-10-17, 6:21 pm |
|
"Ulysses" <therealulysses@yahoo.com> wrote in message
news:11l7u51h5euml62@corp.supernews.com...
>
> "Robert Morein" <nowhere@nowhere.com> wrote in message
> news:8vOdncVfIZQtIM7eRVn-sQ@giganews.com...
> 60Hz.
It[color=darkred]
> anything
> Supply
probably[color=darkred]
> socket
watts.[color=darkred]
> I
> is
>
> Are you running a small country or something? I don't even know what most
> of the stuff is that you are talking about. What do you use it for?
The two larger machines are used for video editing and software development.
>
> BTW, just to stay on topic, my computer uses about 95 watts--2.4G Desktop
> with a 15" LCD monitor.
That's nice. Unfortunately for my power bill, I'm an ex-hacker addicted to
lalrge screen real estate.
This is according to my Vector inverter with
> built-in watt meter so it may not be real accurate. Turning on the inkjet
> printer makes it jump to 105 watts.
>
>
| |
| Robert Morein 2005-10-17, 6:21 pm |
|
<tkgoogle@ktcnslt.com> wrote in message
news:1129571105.882816.166100@z14g2000cwz.googlegroups.com...
> Robert Morein wrote:
>
60Hz.[color=darkred]
>
> For CRT's, try measuring the power consumption while displaying an
> white screen. (or just set screen background color to white.) Don't
> be surprised if power consumption increases by 50% or more.
>
No difference here.
> A 21.3" Samsung 213t LCD monitor (1600x1200) consumes about 38 watts.
>
>
It[color=darkred]
anything[color=darkred]
>
> Multiple UPS's are a big consumer of energy. Consider using a single
> larger standby UPS, the energy savings can be significant.
>
> Consider something really big, but not TOO big, like a Tripp-lite
> Power verter.. APS-912 .. APS-1012.
But that's the same capacity as what I have:
http://www.cyberpowersystems.com/CPS1500AVR.asp.
They have quick switching times and
> function just like a big UPS. Connect them up to a Group-27 Deep cycle
> Trolling Bat and you'll have enough standby power to run ALL your PC's
> for hour or two.
>
> During float/standby operation a APS-912 power consumes ~13 watts.
That is nice. I suspect that the AVR autotransformer in the Cyberpower units
eats juice.
>
>
> How did you measure power consumption fibre optic links??
They have analog wall warts plugged into a strip.
>
> Careful selection of replacements can save considerable amounts of
> energy. For example.. my newly purchased linux based Actiontec DSL
> modem/firewall/router/4port hub consumes far less power than the
> components it replaced. (~5 watts verses ~13 watts).
>
What's annoying about the problem is that EVERYTHING eats power. There's a
lot of infrastructure to replace.
> Likewise.. a modern Dlink DSS-16+ (16 port Enet-switch ~3 watts)
> draws a fraction of the power needed by some of my older ethernet hubs
> and switches.
I suspect the difference is from the use of switching wall warts.
>
>
> What's the idle consumption? (which OS's are you using?)
That is idle. XP.
>
> NT & ?W2K? are not known for activating CPU power saving function
> when running MP kernel.
I'm not unhappy about it. I expected far higher from that machine.
>
Supply[color=darkred]
probably[color=darkred]
>
> Same questions as those for item 4.
XP. The heatsink, which is only semi exotic (a bunch of serrated rods
splayed out from the contact block, topped with an 80mm fan) runs dead cool
to the touch.
>
socket[color=darkred]
>
> 100Watts seams a bit on the high side.. What is the OS?
W2K
how many
> other un-needed components are plugged in and powered up.. Floppy?,
YES.
> CD?
, DVD?, -R's, disks?, etc..
Plextor CDRW, Pioneer A06, three Seagate 80gb Barracuda IV's, which are set
to power down at idle.
>
> Older desktop OS's 95,98,ME don't activate the power saving
> function of CPU..
It's W2K
>
> Get one of the well known Halt/Idle programs PC's running older OS's..
> http://www.benchtest.com/coolarch.html (several are free)..
>
> As a reference.. I getting ready to phase in a recycled 1U firewall
> as my new email/ftp/web server.. it's based on AMD K6-2 300 mhz.. 1
> disk.. no video or other components and consumes about 18 watts.
>
I assume you're off grid. Otherwise, I would not want to use a machine that
is appreciably slower than the connection in loading web pages. Actually, I
do! The C3, at 1 gHz, is slower with the web, and with downloads, than the
other machines. Part of this may be due to "funniness" of the C3, rather
than the actual clock speed.
watts. I[color=darkred]
is[color=darkred]
>
> Lastly.. Shutoff screen savers which constantly draw patterns on
> display, those unnessary features consume considerable power. Just set
> screen saver to blank or none and adjust monitor standby options.
>
That is exactly what I do. If a machine crashes, I don't want to see the
screensaver etched on the monitor. And they power off in 15 minutes.
| |
| Pete C. 2005-10-17, 8:21 pm |
| Robert Morein wrote:
>
> I used a Kill A Watt to analyze my setup. There were some surprises:
>
> 1. Modern 21" Sony based WEGA monitors use only 80 watts a 1600x1200, 60Hz.
> This isn't much more than a flat panel.
> 2. CyberPower 1500VA UPSes measured at 30 watts no load, fully charged. It
> was quite a disappointment that they are such power hogs. Is there anything
> more efficient in this power range?
> 3. Cable modem, routers, firewalls, VoIP appliance, fiber optic links
> totaled around 80 watts.
> 4. A Dual Athlon with an Nvidia 5900 came in at a mere 225 watts while
> running in 2D mode. PS is a 600W PF neutralized Silenx, which is made by
> Fortron.
> 5. A P4 2.6/400 with an Nvidia 5200 came in at 150 watts, in 2D mode. Supply
> is a less efficient 400W Computer Warehouse, not PF neutralized, probably
> also made by Fortron.
> 6. A Via C3 low power machine, which I constructed using a Supermicro socket
> 370 mb, for use as an email/text processing always-on machine, was a bit
> disappointing. In spite of the fact that this processor idles at just a
> couple watts, total power draw was 100 watts. Video card is a fanless 2D
> only Matrox G550. Power supply is a PF neutralized Silenx 350 watt unit.
> Where is all the power going?
>
> Total power draw with just the Via machine two 21" monitors is 383 watts. I
> can knock off 80 watts by turning off one of the monitors, but the total is
> still disappointing.
>
> Comments?
A couple thoughts...
For the cable modem, router, firewalls, etc., if they are the consumer
type with 12v wall warts for power, you can generally improve efficiency
by replacing all the warts with a single larger high quality switching
supply.
For the UPS, be sure to measure a few decent loads, put them on the UPS
and then measure the total to get a better idea of the UPS's
consumption. An unloaded UPS's consumption may not accurately reflect
it's consumption when at a moderate load depending on it's design.
Pete C.
| |
| Vaughn 2005-10-17, 8:21 pm |
|
"Danno" <TOOmuchSPAM@hotmail.com> wrote in message
news:slrndl7juq.2iv.TOOmuchSPAM@3250H1.danux.net...
> You may want to measure your computers again, but set your Kill-A-Watt
> meter to Volt-Amps instead of Watts. The true power consumption of electronic
> equipment doesn't measure well with the "Watts" setting. For instance, I have
> a 19" NEC CRT, which comes in between 60-90 watts, but the VA measurement
> shows an average of about 150VA. Quite a difference. The watt measurement
> works well for things like lights and coils, but VA is better for things like
> computers and stereos.
I am a bit lost here. Do you understand the relationship between Watts,
VA, and Power Factor? (True Power = Apparent Power X Power Factor.) If (for
example) your KAW reads 75 Watts and 150 VA, that implies a Power Factor of 2.
2 is a terrible power factor, but about normal for today's electronics with
switching power supplies. Is that about what the KAW is indicating? If so, it
is working properly.
Vaughn
| |
| Derek Broughton 2005-10-17, 9:21 pm |
| Robert Morein wrote:
> I assume you're off grid. Otherwise, I would not want to use a machine
> that is appreciably slower than the connection in loading web pages.
Maybe you're seeing something I'm not, but I can easily imagine an AMD K6
300Mhz machine keeping up with a measly DSL connection. Linux geeks
routinely use machines smaller than that for firewalls.
--
derek
| |
| RF Dude 2005-10-17, 10:21 pm |
| PF is a number less than or equal to 1.0. Resistor loads are 1.0. Then you
have leading and lagging PF depending on if it is capacitive or inductive.
| |
| RF Dude 2005-10-17, 10:21 pm |
| Correct me if I'm wrong, but at this price point, I don't believe these
Kill-a-Watt type devices are measuring TRUE RMS current and voltage. All
measurements are based on sine wave equivalent. Your non-PF corrected
switch mode power supplies conduct current only at or near the voltage
peaks. They produce lots of harmonics and Total Harmonic Distortion on the
current waveform. In other words, they won't read accurate with electronic
loads. Resistors and motors are OK as well as PF-corrected electronics
only.
RF Dude.
| |
| Robert Morein 2005-10-17, 10:21 pm |
|
"RF Dude" <post@thisnewsgroup.com> wrote in message
news:fHX4f.9746$ns3.448556@news20.bellglobal.com...
> Correct me if I'm wrong, but at this price point, I don't believe these
> Kill-a-Watt type devices are measuring TRUE RMS current and voltage. All
> measurements are based on sine wave equivalent. Your non-PF corrected
> switch mode power supplies conduct current only at or near the voltage
> peaks. They produce lots of harmonics and Total Harmonic Distortion on
the
> current waveform. In other words, they won't read accurate with
electronic
> loads. Resistors and motors are OK as well as PF-corrected electronics
> only.
>
> RF Dude.
>
So is the actual billed power higher or lower than the Kill-a-Watt reading?
BTW, Watts and VA on this device are within afew percent.
| |
| Danno 2005-10-17, 10:21 pm |
| On 2005-10-17, Vaughn <vaughnsimonHATESSPAM@att.fake.net> wrote:
>
> "Danno" <TOOmuchSPAM@hotmail.com> wrote in message
> news:slrndl7juq.2iv.TOOmuchSPAM@3250H1.danux.net...
>
> I am a bit lost here. Do you understand the relationship between Watts,
> VA, and Power Factor? (True Power = Apparent Power X Power Factor.)
Heh. Nope, hadn't heard of "Power Factor" before. Does the pwoer factor have
to be included when calculating actual consumption? Like, in your example
following, is the device drawing 75 units or 150 units of power? I have been
working under the assumption that the VA reading was indicating the actual
amount of energy being drawn. Is "Power Factor" a measure of true
consmption, or a measure of efficiency?
Which reading would you use, if you were calculating the size of a
battery bank for a set of computers?
> If (for
> example) your KAW reads 75 Watts and 150 VA, that implies a Power Factor of 2.
> 2 is a terrible power factor, but about normal for today's electronics with
> switching power supplies. Is that about what the KAW is indicating? If so, it
> is working properly.
>
> Vaughn
>
>
--
Slackware 9.1, 2.4.31, A7V333 AthlonXP2600+, Ti4200
RLU #272755
| |
| Solar Flare 2005-10-17, 10:21 pm |
| And VA do not add up uness all the power factors are the same (not likely). You
have to have Watts and Vars (reactive Power) to each add up and then do the
Pythagorean thing on them.
VAt^2 = Wt^2 + RVAt^2
"Vaughn" <vaughnsimonHATESSPAM@att.fake.net> wrote in message
news:8dW4f.451095$5N3.245854@bgtnsc05-news.ops.worldnet.att.net...
>
> "Danno" <TOOmuchSPAM@hotmail.com> wrote in message
> news:slrndl7juq.2iv.TOOmuchSPAM@3250H1.danux.net...
electronic[color=darkred]
have[color=darkred]
like[color=darkred]
>
> I am a bit lost here. Do you understand the relationship between Watts,
> VA, and Power Factor? (True Power = Apparent Power X Power Factor.) If
(for
> example) your KAW reads 75 Watts and 150 VA, that implies a Power Factor of 2.
> 2 is a terrible power factor, but about normal for today's electronics with
> switching power supplies. Is that about what the KAW is indicating? If so,
it
> is working properly.
>
> Vaughn
>
>
| |
| Vaughn 2005-10-17, 10:21 pm |
|
"RF Dude" <post@thisnewsgroup.com> wrote in message
news:2AX4f.9739$ns3.445973@news20.bellglobal.com...
> PF is a number less than or equal to 1.0. Resistor loads are 1.0. Then you
> have leading and lagging PF depending on if it is capacitive or inductive.
<Blush> You are exactly right. VA X Power Factor = True Power. Danno's
monitor has a power factor of .5 (not 2). I don't have my KAW here at home to
compare, but the figures he presented still sound about right. I don't have any
expensive test equipment to compare my KAW to, but the figures I have seen on
mine for Watts, VA and PF seem plenty believable enough for normal work. YMMV
Vaughn
>
>
| |
| Solar Flare 2005-10-17, 11:21 pm |
| 150 VA is the power your generator source has to put out. 75Watts is the power
your load makes efficient usage of.
"Danno" <TOOmuchSPAM@hotmail.com> wrote in message
news:slrndl8ich.2q2.TOOmuchSPAM@A7V333.danux.net...
> On 2005-10-17, Vaughn <vaughnsimonHATESSPAM@att.fake.net> wrote:
electronic[color=darkred]
have[color=darkred]
like[color=darkred]
Watts,[color=darkred]
>
> Heh. Nope, hadn't heard of "Power Factor" before. Does the pwoer factor have
> to be included when calculating actual consumption? Like, in your example
> following, is the device drawing 75 units or 150 units of power? I have been
> working under the assumption that the VA reading was indicating the actual
> amount of energy being drawn. Is "Power Factor" a measure of true
> consmption, or a measure of efficiency?
> Which reading would you use, if you were calculating the size of a
> battery bank for a set of computers?
>
>
2.[color=darkred]
it[color=darkred]
>
>
> --
> Slackware 9.1, 2.4.31, A7V333 AthlonXP2600+, Ti4200
> RLU #272755
| |
| Solar Flare 2005-10-17, 11:21 pm |
| I haven't check the Lill-a-watt meters (have 3) for distortion accuracy but I
will tell you this. The three units I have are almost as accurate as our lab
standards traceable to the NBS standards on non-distorted waveforms. I doubt
they use any form factor with that accuracy. It is just too easy to measure and
calculate real power values today in a CPU chip.
"RF Dude" <post@thisnewsgroup.com> wrote in message
news:fHX4f.9746$ns3.448556@news20.bellglobal.com...
> Correct me if I'm wrong, but at this price point, I don't believe these
> Kill-a-Watt type devices are measuring TRUE RMS current and voltage. All
> measurements are based on sine wave equivalent. Your non-PF corrected
> switch mode power supplies conduct current only at or near the voltage
> peaks. They produce lots of harmonics and Total Harmonic Distortion on the
> current waveform. In other words, they won't read accurate with electronic
> loads. Resistors and motors are OK as well as PF-corrected electronics
> only.
>
> RF Dude.
>
>
| |
| Pete C. 2005-10-17, 11:21 pm |
| RF Dude wrote:
>
> Correct me if I'm wrong, but at this price point, I don't believe these
> Kill-a-Watt type devices are measuring TRUE RMS current and voltage. All
> measurements are based on sine wave equivalent. Your non-PF corrected
> switch mode power supplies conduct current only at or near the voltage
> peaks. They produce lots of harmonics and Total Harmonic Distortion on the
> current waveform. In other words, they won't read accurate with electronic
> loads. Resistors and motors are OK as well as PF-corrected electronics
> only.
>
> RF Dude.
Entirely possible. I've never used a Kill-a-Watt, I have a Fluke 87.
My point though was that a single good 12v power supply is usually more
efficient than a handful of wall wart 12v power supplies and also that a
UPS's own power consumption at zero load vs. with a load is not always
the same.
Pete C.
| |
| Robert Morein 2005-10-18, 2:21 am |
|
"Pete C." <aux3.DOH.4@snet.net> wrote in message
news:435459E4.DA21F426@snet.net...
> RF Dude wrote:
All[color=darkred]
the[color=darkred]
electronic[color=darkred]
>
> Entirely possible. I've never used a Kill-a-Watt, I have a Fluke 87.
>
> My point though was that a single good 12v power supply is usually more
> efficient than a handful of wall wart 12v power supplies and also that a
> UPS's own power consumption at zero load vs. with a load is not always
> the same.
>
> Pete C.
Since these are standby supplies, rather than true UPSes, I don't see why
there would be any load dependency.
I think the autoformer used for line voltage regulation is the cause of the
high idle consumption.
| |
| Vaughn 2005-10-18, 8:21 am |
|
"Danno" <TOOmuchSPAM@hotmail.com> wrote in message
news:slrndl8ich.2q2.TOOmuchSPAM@A7V333.danux.net...
> On 2005-10-17, Vaughn <vaughnsimonHATESSPAM@att.fake.net> wrote:
> Which reading would you use, if you were calculating the size of a
> battery bank for a set of computers?
Watts.
I suggest that you read up a bit on power factor, it is one of those
non-intuitive things. For an example, look deep into the literature of your
computer UPS. It was probably labeled in large letters on the outside of the
box as something like "500 VA". If you look closely at the data sheet, you will
find that they assumed a .5 power factor and the actual rating of the UPS is
something like "250 Watts".
Vaughn
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| Pete C. 2005-10-18, 11:21 am |
| Robert Morein wrote:
>
> "Pete C." <aux3.DOH.4@snet.net> wrote in message
> news:435459E4.DA21F426@snet.net...
> All
> the
> electronic
>
> Since these are standby supplies, rather than true UPSes, I don't see why
> there would be any load dependency.
> I think the autoformer used for line voltage regulation is the cause of the
> high idle consumption.
Like I said, depending on the design. Easy enough to test with a
measured load and see if there is a difference for that particular unit.
Pete C.
| |
|
| In article
<8dW4f.451095$5N3.245854@bgtnsc05-news.ops.worldnet.att.net>,
"Vaughn" <vaughnsimonHATESSPAM@att.fake.net> wrote:
> I am a bit lost here. Do you understand the relationship between Watts,
> VA, and Power Factor? (True Power = Apparent Power X Power Factor.) If
> (for
> example) your KAW reads 75 Watts and 150 VA, that implies a Power Factor of
> 2.
> 2 is a terrible power factor, but about normal for today's electronics with
> switching power supplies. Is that about what the KAW is indicating? If so,
> it
> is working properly.
>
> Vaughn
Now I am very confused...."that implies a Power Factor of 2."
Since PF has a Maximum Value of 1.0, how can one have a PF of 2?
Please explain.....
Me
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| Vaughn Simon 2005-10-18, 4:21 pm |
|
"Me" <Me@shadow.orgs> wrote in message
news:Me-E09486.08551118102005@netnews.worldnet.att.net...
> Now I am very confused...."that implies a Power Factor of 2."
> Since PF has a Maximum Value of 1.0, how can one have a PF of 2?
Sorry. I inverted the formula in my brain. I suppose I should refrain
from posting while standing on my head. In that example, the pf should have
been .5, not 2.
Vaughn
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| Loren Amelang 2005-10-18, 4:21 pm |
| On Tue, 18 Oct 2005 00:59:54 GMT, Danno <TOOmuchSPAM@hotmail.com>
wrote:
>Heh. Nope, hadn't heard of "Power Factor" before. Does the pwoer factor have
>to be included when calculating actual consumption? Like, in your example
>following, is the device drawing 75 units or 150 units of power? I have been
>working under the assumption that the VA reading was indicating the actual
>amount of energy being drawn. Is "Power Factor" a measure of true
>consmption, or a measure of efficiency?
> Which reading would you use, if you were calculating the size of a
>battery bank for a set of computers?
It depends on the source of your AC power. I once got pretty deeply
into investigating PF in my off-grid system, and concluded that for my
Trace SW4024, with 90+ pounds of iron inside, power factor made little
difference in the amount of DC consumed at the input.
Utilities are only concerned about power factor for large loads, where
the extra cost of capability to transmit the reflected power, and the
heat load it adds to their generating and transmission equipment,
becomes significant. Except for what is lost as heat, the reflected
power itself comes back to them and does not increase their fuel cost.
Likewise, in my heavy transformer based Trace, the reflected power
appears to return to the inductance of the inverter with no net impact
on the DC input side.
My measurements of several (admittedly lower wattage) inverters that
do not use a heavy transformer on the 60 Hz side showed the opposite -
they were unable to absorb the reflected power for re-use, instead
dissipating it as heat. Adding PF correction capacitors reduced their
DC input load significantly, and made them run cooler and sound much
happier.
So whether the example system is burning through 75 or 150 DC input
watts probably depends on the design of the inverter. I'd love to hear
real world measurements of how other inverters respond to power factor
- along with their weight...
Loren
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|
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| Pete C 2005-10-18, 5:21 pm |
| On Mon, 17 Oct 2005 10:42:51 -0400, "Robert Morein"
<nowhere@nowhere.com> wrote:
>I used a Kill A Watt to analyze my setup. There were some surprises:
>
>1. Modern 21" Sony based WEGA monitors use only 80 watts a 1600x1200, 60Hz.
>This isn't much more than a flat panel.
>2. CyberPower 1500VA UPSes measured at 30 watts no load, fully charged. It
>was quite a disappointment that they are such power hogs. Is there anything
>more efficient in this power range?
>3. Cable modem, routers, firewalls, VoIP appliance, fiber optic links
>totaled around 80 watts.
>4. A Dual Athlon with an Nvidia 5900 came in at a mere 225 watts while
>running in 2D mode. PS is a 600W PF neutralized Silenx, which is made by
>Fortron.
>5. A P4 2.6/400 with an Nvidia 5200 came in at 150 watts, in 2D mode. Supply
>is a less efficient 400W Computer Warehouse, not PF neutralized, probably
>also made by Fortron.
>6. A Via C3 low power machine, which I constructed using a Supermicro socket
>370 mb, for use as an email/text processing always-on machine, was a bit
>disappointing. In spite of the fact that this processor idles at just a
>couple watts, total power draw was 100 watts. Video card is a fanless 2D
>only Matrox G550. Power supply is a PF neutralized Silenx 350 watt unit.
>Where is all the power going?
>
>Total power draw with just the Via machine two 21" monitors is 383 watts. I
>can knock off 80 watts by turning off one of the monitors, but the total is
>still disappointing.
>
>Comments?
>
Hi,
Lowest energy setup would be a Pentium M laptop and flat monitor(s)
I'd expect.
For a PC that needs to be always on and silent, I reckon a Pentium M
laptop or similar is cheaper overall than a desktop once the cost of
energy and silencing mods (to the desktop) are considered.
Some of the newer all in one wireless modem/routers have lower power
processors than existing stuff, 12w or less.
I have a UPS but will only use it if the supply becomes unreliable,
after all an outage isn't much worse than a BSOD.
cheers,
Pete.
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| mike wilcox 2005-10-18, 6:21 pm |
| Pete C wrote:
> On Mon, 17 Oct 2005 10:42:51 -0400, "Robert Morein"
> <nowhere@nowhere.com> wrote:
>
>
>
>
> Hi,
>
> Lowest energy setup would be a Pentium M laptop and flat monitor(s)
> I'd expect.
>
> For a PC that needs to be always on and silent, I reckon a Pentium M
> laptop or similar is cheaper overall than a desktop once the cost of
> energy and silencing mods (to the desktop) are considered.
>
> Some of the newer all in one wireless modem/routers have lower power
> processors than existing stuff, 12w or less.
>
> I have a UPS but will only use it if the supply becomes unreliable,
> after all an outage isn't much worse than a BSOD.
>
> cheers,
> Pete.
The savings depends on your situation. Whatever amount of electricity
you are using, most of it you get back in heat, which in my part of
Canada from September to mid April is not a bad thing ;~) Right now my
Comp and old UPS is serving as a foot warmers as I work ;~). I had toyed
with the idea of building a 8'x10' office with 2"x8" walls, 12" ceiling
insulation and heating it with the wallwarts, ups, monitor, printer,
modem etc.... Maybe Nick might have a heat loss equation for this ;~)
| |
| zenboom 2005-10-19, 6:21 am |
|
"mike wilcox" <appraisers@sympatico.ca> wrote in message
news:uRc5f.10254$ns3.649521@news20.bellglobal.com...
<snip>
>
> The savings depends on your situation. Whatever amount of electricity
> you are using, most of it you get back in heat, which in my part of
> Canada from September to mid April is not a bad thing ;~) Right now my
> Comp and old UPS is serving as a foot warmers as I work ;~). I had toyed
> with the idea of building a 8'x10' office with 2"x8" walls, 12" ceiling
> insulation and heating it with the wallwarts, ups, monitor, printer,
> modem etc.... Maybe Nick might have a heat loss equation for this ;~)
LOL ... new concept in alternative energy?! microCombinedHeat&'Puting
| |
| mike wilcox 2005-10-19, 9:21 am |
| zenboom wrote:
> "mike wilcox" <appraisers@sympatico.ca> wrote in message
> news:uRc5f.10254$ns3.649521@news20.bellglobal.com...
>
> <snip>
>
>
>
> LOL ... new concept in alternative energy?! microCombinedHeat&'Puting
>
>
I first thought of this after installing compact florecent lights, then
noticing the room seem cooler, but my feet were warm by the comp & gear.
The old incadesents in my desk lamps were throwing off heat I could feel ;~)
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|
| On 2005-10-18, Loren Amelang <loren@pacific.net> wrote:
>
> It depends on the source of your AC power. I once got pretty deeply
> into investigating PF in my off-grid system, and concluded that for my
> Trace SW4024, with 90+ pounds of iron inside, power factor made little
> difference in the amount of DC consumed at the input.
>
> Utilities are only concerned about power factor for large loads, where
> the extra cost of capability to transmit the reflected power, and the
> heat load it adds to their generating and transmission equipment,
> becomes significant. Except for what is lost as heat, the reflected
> power itself comes back to them and does not increase their fuel cost.
> Likewise, in my heavy transformer based Trace, the reflected power
> appears to return to the inductance of the inverter with no net impact
> on the DC input side.
>
> My measurements of several (admittedly lower wattage) inverters that
> do not use a heavy transformer on the 60 Hz side showed the opposite -
> they were unable to absorb the reflected power for re-use, instead
> dissipating it as heat. Adding PF correction capacitors reduced their
> DC input load significantly, and made them run cooler and sound much
> happier.
>
> So whether the example system is burning through 75 or 150 DC input
> watts probably depends on the design of the inverter. I'd love to hear
> real world measurements of how other inverters respond to power factor
> - along with their weight...
>
> Loren
<nod>, OK I am beginning to see now. Thanks for the depth (and to the
other posters as well) in your post.
--
Solar-powered Linux: Slackware 10.0, 2.6.13, Averatec 3250H1 w/accel S3Uni
RLU#272755
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| Jim Baber 2005-11-02, 3:21 pm |
|
Danno wrote:
>On 2005-10-17, Robert Morein <nowhere@nowhere.com> wrote:
>
>
>
> Found the same with my C3 integrated board (1-Gigapro); used far more power
>than I expected it to.
> The best consumption I've found is from an IBM Thinkpad 560, P100, DSTN,
>no optical or floppy drive: in normal use, runs between 11 and 20 watts
>(19 - 30 Volt-Amps). It works well for basic tasks.
> You may want to measure your computers again, but set your Kill-A-Watt
>meter to Volt-Amps instead of Watts. The true power consumption of electronic
>equipment doesn't measure well with the "Watts" setting. For instance, I have
>a 19" NEC CRT, which comes in between 60-90 watts, but the VA measurement
>shows an average of about 150VA. Quite a difference. The watt measurement
>works well for things like lights and coils, but VA is better for things like
>computers and stereos.
>
>
Jim's question:
Danno, you say VA is better for these things, but are you being billed
for Watts or VA by your utility? Seems to me you should be testing to
determine the best (least value) in the manner you are being charged,
and in my case, Pacific Gas & Electric charges are based on the use of
kWh for the unit of measure for the usual account categories not VA.
| |
| Jim Baber 2005-11-02, 4:21 pm |
|
Loren Amelang wrote:
>On Tue, 18 Oct 2005 00:59:54 GMT, Danno <TOOmuchSPAM@hotmail.com>
>wrote:
>
>
>
>
>It depends on the source of your AC power. I once got pretty deeply
>into investigating PF in my off-grid system, and concluded that for my
>Trace SW4024, with 90+ pounds of iron inside, power factor made little
>difference in the amount of DC consumed at the input.
>
>Utilities are only concerned about power factor for large loads, where
>the extra cost of capability to transmit the reflected power, and the
>heat load it adds to their generating and transmission equipment,
>becomes significant. Except for what is lost as heat, the reflected
>power itself comes back to them and does not increase their fuel cost.
>Likewise, in my heavy transformer based Trace, the reflected power
>appears to return to the inductance of the inverter with no net impact
>on the DC input side.
>
>My measurements of several (admittedly lower wattage) inverters that
>do not use a heavy transformer on the 60 Hz side showed the opposite -
>they were unable to absorb the reflected power for re-use, instead
>dissipating it as heat. Adding PF correction capacitors reduced their
>DC input load significantly, and made them run cooler and sound much
>happier.
>
>So whether the example system is burning through 75 or 150 DC input
>watts probably depends on the design of the inverter. I'd love to hear
>real world measurements of how other inverters respond to power factor
>- along with their weight...
>
>Loren
>
>
Jim Baber's Reply to Loren
I have had a lot of comments made to me about PF when I made some
comments quite a while ago.
First you have to understand a little of my history. In the 1960's I
worked for NCR as a hardware Design Engineer (Electro-Mech.) and one
project I was involved with was to improve the efficiency of our main
frame computers power supplies to reduce our customer's power costs. I
suggested that by correcting the power factor of our transformer based
internal power supplies with power factor correction capacitors, we
would reduce the measured wattage the customer was billed for. It was a
suggestion that was quickly accepted, and included in the design,
because it also reduced the heat generated in the power supplies. I
didn't think about this again for the forty + years until I installed
a 10 kW Photo Voltaic solar system on my home in 2002.
My system works well and at the end of the first year, I was pleased to
only owe PG&E $450 (the prior year's bill was $5,005) and my total
wattage was still about 26,000 kWh for the year. But, I got to thinking
that rather than adding more generating capacity, I really needed to
reduce our usage, so I became the energy police. Fortunately, I
remembered the bit about power factors, before my family divorced me. I
bought a rather expensive power factor meter (over $800) that would
record our power factor history a week at a time, and discovered the
whole house generally average about a 0.71 pf. This is terrible because
pf should ideally be 1.0. I eventually found a source of correction
capacitors and bought one that brought our home up to a 0.97 pf.
Result: the second year we used our solar system, our total wattage from
the both grid and the solar system dropped to 18,500 kWh a major
improvement of 28.9% less wattage used. We did not have to pay for any
additional power on our annual settlement this year, in fact we still
had a ($458) credit at the end of the billing year. Unfortunately, that
is wiped out per agreement, too bad they don't pay me any cash for it.
Power Factor is very important at least in my case with the Sunny Boy
inverters I have.
| |
| Loren Amelang 2005-11-03, 3:21 pm |
| On Wed, 02 Nov 2005 11:59:04 -0800, Jim Baber <jim@baber.org> wrote:
....
> But, I got to thinking
>that rather than adding more generating capacity, I really needed to
>reduce our usage, so I became the energy police. Fortunately, I
>remembered the bit about power factors, before my family divorced me. I
>bought a rather expensive power factor meter (over $800) that would
>record our power factor history a week at a time, and discovered the
>whole house generally average about a 0.71 pf. This is terrible because
>pf should ideally be 1.0. I eventually found a source of correction
>capacitors and bought one that brought our home up to a 0.97 pf.
>
>Result: the second year we used our solar system, our total wattage from
>the both grid and the solar system dropped to 18,500 kWh a major
>improvement of 28.9% less wattage used. We did not have to pay for any
>additional power on our annual settlement this year, in fact we still
>had a ($458) credit at the end of the billing year. Unfortunately, that
>is wiped out per agreement, too bad they don't pay me any cash for it.
>
>Power Factor is very important at least in my case with the Sunny Boy
>inverters I have.
Am I correct in believing the Sunny Boy inverters do use a heavy 60 Hz
transformer on their output side? If so I would have to imagine the
difference between your experience that power factor is important, and
my tests showing power factor didn't matter to my Trace SW4024, would
be in the percentage of load the inverters were seeing.
My tests were with loads under 100 watts, representative of the things
that run for long time periods here (and the only things I had big
enough PF correction capacitors to compensate). I can easily imagine
that as the loads get larger relative to the capacity of the 60 Hz
transformer in the inverter, the percentage of reflected power it can
absorb and re-use declines, and power factor becomes more important.
My only large load that runs enough of the time for PF to matter is
the deep well pump, and lucky for me the electronics in my Grundfos
SQE provide an almost perfect power factor. Sometimes those European
design requirements come in handy.
Loren
| |
| Jim Baber 2005-11-04, 5:21 pm |
|
Loren Amelang wrote:
>On Wed, 02 Nov 2005 11:59:04 -0800, Jim Baber <jim@baber.org> wrote:
>....
>
>
>
>Am I correct in believing the Sunny Boy inverters do use a heavy 60 Hz
>transformer on their output side? ...........
>
It does show a transformer in the inverter's block diagram, but I don't
remember it as being very large or even obvious when I was installing my
inverters. The entire unit only weighs 70 lbs, and considering since
the case is 10 ga.stainless steel and is 17" * 12" * 8" and has a 17" *
8" stainless internal partition. Logic tells me the transformer can't
be too large. The inverters have a 1.0 pf per specification
themselves. SMA America told me that adding pf correction would not
hurt the inverters, and that they wished all users would, but they
didn't feel it was functionally necessary.
>............ If so I would have to imagine the
>difference between your experience that power factor is important, and
>my tests showing power factor didn't matter to my Trace SW4024, would
>be in the percentage of load the inverters were seeing.
>
>My tests were with loads under 100 watts, representative of the things
>that run for long time periods here (and the only things I had big
>enough PF correction capacitors to compensate). I can easily imagine
>that as the loads get larger relative to the capacity of the 60 Hz
>transformer in the inverter, the percentage of reflected power it can
>absorb and re-use declines, and power factor becomes more important.
>
>My only large load that runs enough of the time for PF to matter is
>the deep well pump, and lucky for me the electronics in my Grundfos
>SQE provide an almost perfect power factor. Sometimes those European
>design requirements come in handy.
>
>Loren
>
>
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