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Power consumption?

Message #1 - Posted 2001/09/20 - Thomas Reed

I've got an old PowerMac 7100/80 that I'd like to be able to leave on all the time with an Ethernet hub hooked up to it so I can transfer stuff from my PB G3 any time, and so both machines can print to my StyleWriter (with the 7100 sharing it over the Ethernet network).

Here's the question, though -- how can I find out how much power leaving the 7100 on will consume? (I would probably run Sleeper on it to reduce consumption, but I don't think the 7100's hardware supports much in the way of sleep.) And how can I find out how much the average simple Ethernet hub would require?

I'm not going to be doing anything with the 7100 every day, so it seems wasteful to use too much power just for the convenience of quick startup now and then.

Thomas Reed

Message #2 - Posted 2001/09/20 - René A. Vega

Thomas Reed wrote:

Here's the question, though -- how can I find out how much power leaving the 7100 on will consume?

Buy a line logger. They are expensive though, almost $400 for one:

http://www.traceoffgrid.com/products/remotecontrols/linelogger/index.html

You can get a rough idea of the power consumption by looking at the power supply rating specs. Multiple the amps times by 110V (assuming this is north american equipment) to get watts. This is the upper end of the machine's power usage.

Look here for specs on all Macs:

http://www.info.apple.com/info.apple.com/applespec/

You will find the 7100/80 consumes 230W max
The 7200/95 dropped to 150W max.

Rene

Message #3 - Posted 2001/09/20 - Matt Broughton

Previously, Thomas Reed wrote:

I've got an old PowerMac 7100/80 that I'd like to be able to leave on all the time with an Ethernet hub hooked up to it so I can transfer stuff from my PB G3 any time, and so both machines can print to my StyleWriter (with the 7100 sharing it over the Ethernet network).

Here's the question, though -- how can I find out how much power leaving the 7100 on will consume? (I would probably run Sleeper on it to reduce consumption, but I don't think the 7100's hardware supports much in the way of sleep.) And how can I find out how much the average simple Ethernet hub would require?

I'm not going to be doing anything with the 7100 every day, so it seems wasteful to use too much power just for the convenience of quick startup now and then.

You might want to check with your electric utility company. Many of them have a device you can borrow that will tell you how much energy an appliance is using.

Matt Broughton

Message #5 - Posted 2001/09/20 - Tom "Tom" Harrington

From a remote bunker, SteveINK (steveink@aol.comornot) issued the following manifesto:

This any help?
http://support.info.apple.com/info.apple.com/applespec/applespec.taf?RID=108

That just gives max power. Unless the system's heavily loaded with cards, extra hard drives, multiple keyboards and the like, it's unlikely to max out the power supply.

Tom "Tom" Harrington ------------ Decode to email: tph (at) pcisys (dot) net "The Revolution Will Not Be Televised"
--Gil Scott-Heron

Message #6 - Posted 2001/09/20 - Thomas Reed

Previously, SteveINK wrote:

This any help?
http://support.info.apple.com/info.apple.com/applespec/applespec.taf?RID=108

Well, I don't know. Let me run this by you and see if my logic makes sense.

That site says the 7100/80 uses 786.6 BTU per hour. According to an online encyclopedia, one BTU is equal to 0.0002928 kilowatt-hours. So, this means the energy usage of the 7100 is 0.23031648 kWh, right?

The problem I see in this is that, according to my understanding, the consumption of a 100-Watt light bulb is 0.1 kWh. Does the 7100 really use only a little more energy per hour than two 100-Watt light bulbs? If so, that doesn't seem like very unreasonable energy usage, especially since most of the time the external monitor would be powered down by Sleeper (and power use of the 7100 itself ought to be lowered a bit as well).

Am I correct, or is there a hole in my logic somewhere?

Thomas Reed

Message #7 - Posted 2001/09/20 - stan

Tom "Tom" Harrington wrote:

From a remote bunker, SteveINK (steveink@aol.comornot) issued the following manifesto:

This any help?
http://support.info.apple.com/info.apple.com/applespec/applespec.taf?RID=108

That just gives max power. Unless the system's heavily loaded with cards, extra hard drives, multiple keyboards and the like, it's unlikely to max out the power supply.

Than again, unless electricity is insanely expensive, does it really matter how much a computer in someone's home uses, from a cost perspective? The electricity can't cost more than a few cents per year even with a sustained maximum load. The biggest current draw probably comes from the monitor and that can safely be turned off when not in use.

Message #8 - Posted 2001/09/20 - Chris Kelly

On 2001.09.20 3:40 PM, in article 200920011440084093%thomasareed@earthlink.net, Thomas Reed wrote:

Previously, SteveINK wrote:

This any help?
http://support.info.apple.com/info.apple.com/applespec/applespec.taf?RID=108

Well, I don't know. Let me run this by you and see if my logic makes sense.

That site says the 7100/80 uses 786.6 BTU per hour. According to an online encyclopedia, one BTU is equal to 0.0002928 kilowatt-hours. So, this means the energy usage of the 7100 is 0.23031648 kWh, right?

The problem I see in this is that, according to my understanding, the consumption of a 100-Watt light bulb is 0.1 kWh. Does the 7100 really use only a little more energy per hour than two 100-Watt light bulbs? If so, that doesn't seem like very unreasonable energy usage, especially since most of the time the external monitor would be powered down by Sleeper (and power use of the 7100 itself ought to be lowered a bit as well).

Am I correct, or is there a hole in my logic somewhere?

I think you are correct. Lightbulbs use an insane amount of energy, hence all of these new long-life low-energy things.

Message #9 - Posted 2001/09/20 - Jonathan Kiang

stan@temple.edu wrote:

Than again, unless electricity is insanely expensive, does it really matter how much a computer in someone's home uses, from a cost perspective? The electricity can't cost more than a few cents per year even with a sustained maximum load. The biggest current draw probably comes from the monitor and that can safely be turned off when not in use.

Well, at a max power of 230 W, there are 8760 hours/year, so that comes to 2014.8 kWh/yr. According to some US DOE numbers, the 1999 US average price was ~$0.065/kWh. Using that price, it comes to $130.96/yr, assuming it's drawing max power for the full year.

The monitor may or may not be included in the 230 W max; it's not clear from the spec page. My guess is that it's not- it just uses a simple power pass through, and not really taxing the power supply, unlike the displays with ADC, which draw their power through the graphics card, which in turn is powered by the power supply.
--
Jon Kiang--
jonathanSINgleDOTkiang@yale.edu
I hate spam, although the pink kind isn't too bad.

Message #10 - Posted 2001/09/20 - Chris Moore

Previously, Thomas Reed wrote:

I've got an old PowerMac 7100/80 that I'd like to be able to leave on all the time with an Ethernet hub hooked up to it so I can transfer stuff from my PB G3 any time, and so both machines can print to my StyleWriter (with the 7100 sharing it over the Ethernet network).

Here's the question, though -- how can I find out how much power leaving the 7100 on will consume? (I would probably run Sleeper on it to reduce consumption, but I don't think the 7100's hardware supports much in the way of sleep.) And how can I find out how much the average simple Ethernet hub would require?

I'm not going to be doing anything with the 7100 every day, so it seems wasteful to use too much power just for the convenience of quick startup now and then.

There is a laptop trick of booting from a RAM Disk to conserve battery life. The hard drive can thus spin down when not in use.

Chris

Message #11 - Posted 2001/09/21 - Fred

Jonathan Kiang wrote:

stan@temple.edu wrote:

Than again, unless electricity is insanely expensive, does it really matter how much a computer in someone's home uses, from a cost perspective? The electricity can't cost more than a few cents per year even with a sustained maximum load. The biggest current draw probably comes from the monitor and that can safely be turned off when not in use.

Well, at a max power of 230 W, there are 8760 hours/year, so that comes to 2014.8 kWh/yr. According to some US DOE numbers, the 1999 US average price was ~$0.065/kWh. Using that price, it comes to $130.96/yr, assuming it's drawing max power for the full year.

The monitor may or may not be included in the 230 W max; it's not clear from the spec page. My guess is that it's not- it just uses a simple power pass through, and not really taxing the power supply, unlike the displays with ADC, which draw their power through the graphics card, which in turn is powered by the power supply.

It's pretty safe to assume that the full 230 W will not be drawn since max capacity includes room for Nubus Cards, possibly additional drives (can't remember what bays a 7100 has).
You can also get Energy Saver (this depends on which system software version you have) to put the computer to sleep, spin down the hard drive etc. which will save a few more watts

Fred

Message #12 - Posted 2001/09/21 - Thomas Reed

Previously, Chris Moore wrote:

There is a laptop trick of booting from a RAM Disk to conserve battery life. The hard drive can thus spin down when not in use.

Not an option -- the machine in question only has 32 MB of RAM, yet needs to have a fairly full install of MacOS 8.6 for other tasks.

Besides, Sleeper ought to be able to spin down its hard drive, right?

Thomas Reed

Message #13 - Posted 2001/09/21 - Tom "Tom" Harrington

From a remote bunker, Thomas Reed (thomasareed@earthlink.net) issued the following manifesto:

That site says the 7100/80 uses 786.6 BTU per hour. According to an online encyclopedia, one BTU is equal to 0.0002928 kilowatt-hours. So, this means the energy usage of the 7100 is 0.23031648 kWh, right?

The problem I see in this is that, according to my understanding, the consumption of a 100-Watt light bulb is 0.1 kWh. Does the 7100 really use only a little more energy per hour than two 100-Watt light bulbs? If so, that doesn't seem like very unreasonable energy usage, especially since most of the time the external monitor would be powered down by Sleeper (and power use of the 7100 itself ought to be lowered a bit as well).

Am I correct, or is there a hole in my logic somewhere?

No, that's exactly right. The 7100's power supply is rated at 230 Watts, maximum. Actual usage depends on what's installed in the system, but you can't go over that w/o upgrading the power supply.

Tom "Tom" Harrington ------------ Decode to email: tph (at) pcisys (dot) net WARNING: This planet contains explicit language, graphic violence, nudity, and adult situations. Self-guidance is recommended.

Message #14 - Posted 2001/09/21 - Tom "Tom" Harrington

From a remote bunker, Jonathan Kiang (lookatmysig@pantheon.yale.edu) issued the following manifesto:

stan@temple.edu wrote:

Than again, unless electricity is insanely expensive, does it really matter how much a computer in someone's home uses, from a cost perspective? The electricity can't cost more than a few cents per year even with a sustained maximum load. The biggest current draw probably comes from the monitor and that can safely be turned off when not in use.

Some people like to consider more than "can I afford it" when deciding whether something represents unnecessary waste.

Well, at a max power of 230 W, there are 8760 hours/year, so that comes to 2014.8 kWh/yr. According to some US DOE numbers, the 1999 US average price was ~$0.065/kWh. Using that price, it comes to $130.96/yr, assuming it's drawing max power for the full year.

The monitor may or may not be included in the 230 W max; it's not clear from the spec page. My guess is that it's not- it just uses a simple power pass through, and not really taxing the power supply, unlike the displays with ADC, which draw their power through the graphics card, which in turn is powered by the power supply.

I'm pretty sure that on these models the monitor would be plugged in separately from the computer.

Tom "Tom" Harrington ------------ Decode to email: tph (at) pcisys (dot) net "Television commercials are a form of religious literature." -Neil Postman

Message #15 - Posted 2001/09/21 - Matt Broughton

Previously, Tom "Tom" Harrington wrote:

From a remote bunker, Jonathan Kiang (lookatmysig@pantheon.yale.edu) issued the following manifesto:

stan@temple.edu wrote:

Than again, unless electricity is insanely expensive, does it really matter how much a computer in someone's home uses, from a cost perspective? The electricity can't cost more than a few cents per year even with a sustained maximum load. The biggest current draw probably comes from the monitor and that can safely be turned off when not in use.

Some people like to consider more than "can I afford it" when deciding whether something represents unnecessary waste.

Thank you for your eloquent and tactful way of putting it. Those are the words for which I have been looking for a while. As someone who took part in events even before the first Earth Day, I have often wanted to make such comment in similar threads like this.

Matt Broughton

Message #16 - Posted 2001/09/21 - stan

Jonathan Kiang wrote:

Well, at a max power of 230 W, there are 8760 hours/year, so that comes to 2014.8 kWh/yr. According to some US DOE numbers, the 1999 US average price was ~$0.065/kWh. Using that price, it comes to $130.96/yr, assuming it's drawing max power for the full year.

It is highly unlikely that a typical home computer would be placed under a full load for an entire year, much less any particular hour of any day of that year.

Message #17 - Posted 2001/09/21 - Matt Neuburg

Previously, stan@temple.edu wrote:

Jonathan Kiang wrote:

Well, at a max power of 230 W, there are 8760 hours/year, so that comes to 2014.8 kWh/yr. According to some US DOE numbers, the 1999 US average price was ~$0.065/kWh. Using that price, it comes to $130.96/yr, assuming it's drawing max power for the full year.

It is highly unlikely that a typical home computer would be placed under a full load for an entire year, much less any particular hour of any day of that year.

Nevertheless, by simply changing to a computer that draws less power, I am using 30% less electricity this year at my house than I was last year. m.

matt neuburg, phd = matt@tidbits.com, http://www.tidbits.com/matt *** REALbasic: The Definitive Guide! ***
http://www.amazon.com/exec/obidos/ASIN/0596001770/somethingsbymatt -- The Second Edition is coming! --

Message #18 - Posted 2001/09/21 - Jonathan Kiang

stan@temple.edu wrote:

Jonathan Kiang wrote:

Well, at a max power of 230 W, there are 8760 hours/year, so that comes to 2014.8 kWh/yr. According to some US DOE numbers, the 1999 US average price was ~$0.065/kWh. Using that price, it comes to $130.96/yr, assuming it's drawing max power for the full year.

It is highly unlikely that a typical home computer would be placed under a full load for an entire year, much less any particular hour of any day of that year.

I agree. But that's the situation your proposed in your statement about the cost, or lack thereof, of running the machine 24-7.

stan@temple.edu wrote:

Than again, unless electricity is insanely expensive, does it really matter how much a computer in someone's home uses, from a cost perspective? The electricity can't cost more than a few cents per year even with a sustained maximum load. The biggest current draw probably comes from the monitor and that can safely be turned off when not in use.

--
Jon Kiang--
jonathanSINgleDOTkiang@yale.edu
I hate spam, although the pink kind isn't too bad.

Message #19 - Posted 2001/09/22 - stan

Matt Neuburg wrote:

Nevertheless, by simply changing to a computer that draws less power, I am using 30% less electricity this year at my house than I was last year. m.

But did this result in a net cost savings after factoring in the cost of the more efficient computer, time transferring files from the old to the new computer, etc.? Also, where's your old computer now? If its in a landfill, then you might have obviated any benefit to the environment by opting for a more energy efficient computer.

Message #20 - Posted 2001/09/22 - Thomas Reed

Previously, stan@temple.edu wrote:

Also, where's your old computer now? If its in a landfill, then you might have obviated any benefit to the environment by opting for a more energy efficient computer.

Since we're talking about a well-known Mac journalist, I think it's quite unlikely that he threw away his old computer. In fact, anybody who throws away a computer rather than donating it do a school or other charity is a numbskull, IMHO.

However, that said, how exactly does the environmental impact of a small lump of plastic, glass and other components in a landfill even REMOTELY compare to a 30%/year energy savings?

Thomas Reed

Message #21 - Posted 2001/09/23 - Charles Martin

Previously, Matt Neuburg wrote:

Previously, stan@temple.edu wrote:

Jonathan Kiang wrote:

Well, at a max power of 230 W, there are 8760 hours/year, so that comes to 2014.8 kWh/yr. According to some US DOE numbers, the 1999 US average price was ~$0.065/kWh. Using that price, it comes to $130.96/yr, assuming it's drawing max power for the full year.

It is highly unlikely that a typical home computer would be placed under a full load for an entire year, much less any particular hour of any day of that year.

Nevertheless, by simply changing to a computer that draws less power, I am using 30% less electricity this year at my house than I was last year. m.

Wow!

Welcome to Macintosh is all I can say about that.

PS. Wonder if the fanless models (ie a 400MHz iMac) use less power than a similarly-rated tower (such as a 400Mhz G3 Blue & White?) --
_Chas_
(non-spammers should use "chasm" at mac-dot-com instead of the email above!)

"Call me old-fashioned, but I want to read email with an email client, news with a newsreader, and browse with a browser. A Swiss army knife is no substitute for a toolbox." -- Kevin Craig, comp.sys.mac.apps

Message #22 - Posted 2001/09/23 - Tom "Tom" Harrington

From a remote bunker, Thomas Reed (thomasareed@earthlink.net) issued the following manifesto:

Previously, stan@temple.edu wrote:

Also, where's your old computer now? If its in a landfill, then you might have obviated any benefit to the environment by opting for a more energy efficient computer.

Since we're talking about a well-known Mac journalist, I think it's quite unlikely that he threw away his old computer. In fact, anybody who throws away a computer rather than donating it do a school or other charity is a numbskull, IMHO.

Who's well-known?

However, that said, how exactly does the environmental impact of a small lump of plastic, glass and other components in a landfill even REMOTELY compare to a 30%/year energy savings?

The most obvious impact is probably from the monitor. When they get really heavy it's because they have a lot of lead in them. The lead can leech into groundwater supplies, which nasty public-health consequences.

Tom "Tom" Harrington ------------ Decode to email: tph (at) pcisys (dot) net "History's a lie that they teach you in school" - Living Color

Message #23 - Posted 2001/09/24 - Thomas Reed

Previously, Tom "Tom" Harrington wrote:

Who's well-known?

Matt Neuburg. The guy whose post you responded to. Have you never read TidBITS?

Thomas Reed

Message #24 - Posted 2001/09/24 - Tom "Tom" Harrington

From a remote bunker, Thomas Reed (thomasareed@earthlink.net) issued the following manifesto:

Previously, Tom "Tom" Harrington wrote:

Who's well-known?

Matt Neuburg. The guy whose post you responded to. Have you never read TidBITS?

Once or twice, but not recently. Probably not in a few years now.

Tom "Tom" Harrington ------------ Decode to email: tph (at) pcisys (dot) net "Things need not have happened to be true. Tales and dreams are the shadow-truth that will endure when mere facts are dust and ashes, and forgot." -- Morpheus

Message #25 - Posted 2001/09/24 - paul beard

in article 200920010955157802%thomasareed@earthlink.net on 9/20/01 7:55 AM, Thomas Reed at thomasareed@earthlink.net opined:

Here's the question, though -- how can I find out how much power leaving the 7100 on will consume? (I would probably run Sleeper on it to reduce consumption, but I don't think the 7100's hardware supports much in the way of sleep.) And how can I find out how much the average simple Ethernet hub would require?

Here's an online calculator that might help get a feel for resource use and budget considerations.

http://www.epa.gov/nrgystar/purchasing/calculators/computersandmonitors-main .html

Message #26 - Posted 2001/09/25 - Ross Bernheim

Tom "Tom" Harrington wrote:

The most obvious impact is probably from the monitor. When they get really heavy it's because they have a lot of lead in them. The lead can leech into groundwater supplies, which nasty public-health consequences.

The 'heavy' in monitors is from the thick glass envelope needed to keep air pressure from imploding the cathode ray tube. The larger the tube, the thicker the glass must be to resist the air pressure. The ammount of lead in a monitor is neglegable, mostly in the lead solder in the electronics.

Ross Bernheim

Message #27 - Posted 2001/09/26 - Clark Martin

in article 200920010955157802%thomasareed@earthlink.net on 9/20/01 7:55 AM,
Thomas Reed at thomasareed@earthlink.net opined:

Here's the question, though -- how can I find out how much power leaving the 7100 on will consume? (I would probably run Sleeper on it to reduce consumption, but I don't think the 7100's hardware supports much in the way of sleep.) And how can I find out how much the average simple Ethernet hub would require?

Here are some numbers I collected:

7100:
Peak (Startup) 61 VA
Nominal 56 VA
Off 16 VA

First off, VA (volt-amps) are NOT the same as watts, watts are less than VA but I don't have the equipment to measure watts so I measured what I could (VA). The "Off" value in particular is certainly very different from the watts consumed.

Viewsonic 15" monitor (Energy Star):
Peak 60 VA
Nominal 60 VA
Standby 7 VA
Off 0 VA

These values are about the same for several Energy Star monitors I have (interestingly enough, my largest, a 17" monitor, has the lowest power draw).

16 port 10BaseT Hub:
Peak (Startup) 30 VA
Nominal 4 VA

And yes, the 7100 can sleep the monitor which is half the power. I don't think you can sleep the HD on a 7100, I can on a 7500 but not on a 7100 to the best of my knowledge.

Clark Martin
Redwood City, CA, USA Macintosh / Internet Consulting

"I'm a designated driver on the Information Super Highway"

Message #28 - Posted 2001/09/26 - Thomas Reed

Previously, Clark Martin wrote:

First off, VA (volt-amps) are NOT the same as watts, watts are less than VA but I don't have the equipment to measure watts so I measured what I could (VA).

Thanks, that's helpful! But, would you mind giving me one other number for comparison? How many VA do you get from a lamp with one 100-watt light bulb?

Thomas Reed

Message #29 - Posted 2001/09/26 - Matt Broughton

Previously, Clark Martin wrote:

in article 200920010955157802%thomasareed@earthlink.net on 9/20/01 7:55 AM,
Thomas Reed at thomasareed@earthlink.net opined:

Here's the question, though -- how can I find out how much power leaving the 7100 on will consume? (I would probably run Sleeper on it to reduce consumption, but I don't think the 7100's hardware supports much in the way of sleep.) And how can I find out how much the average simple Ethernet hub would require?

Here are some numbers I collected:

7100:
Peak (Startup) 61 VA
Nominal 56 VA
Off 16 VA

First off, VA (volt-amps) are NOT the same as watts, watts are less than VA but I don't have the equipment to measure watts so I measured what I could (VA). The "Off" value in particular is certainly very different from the watts consumed.

Viewsonic 15" monitor (Energy Star):
Peak 60 VA
Nominal 60 VA
Standby 7 VA
Off 0 VA

These values are about the same for several Energy Star monitors I have (interestingly enough, my largest, a 17" monitor, has the lowest power draw).

16 port 10BaseT Hub:
Peak (Startup) 30 VA
Nominal 4 VA

And yes, the 7100 can sleep the monitor which is half the power. I don't think you can sleep the HD on a 7100, I can on a 7500 but not on a 7100 to the best of my knowledge.

By sleep the HD do you mean spin down? (I too often misuse terms.) If so, Sleeper should be able to spin down the HD. I've used it as far back as an LCIII to spin down the HD.

Matt Broughton

Message #30 - Posted 2001/09/26 - Matthew Russotto

Previously, Thomas Reed wrote:

Previously, Clark Martin wrote:

First off, VA (volt-amps) are NOT the same as watts, watts are less than VA but I don't have the equipment to measure watts so I measured what I could (VA).

Thanks, that's helpful! But, would you mind giving me one other number for comparison? How many VA do you get from a lamp with one 100-watt light bulb?

100. The difference doesn't apply to purely resistive loads.

Matthew T. Russotto russotto@pond.com =====
Get Caught Reading, Go To Jail!
A message from the Association of American Publishers
Free Dmitry Sklyarov! DMCA delenda est! http://www.freedmitry.org

Message #31 - Posted 2001/09/30 - Clark Martin

Previously, Matt Broughton wrote:

Previously, Clark Martin wrote:

And yes, the 7100 can sleep the monitor which is half the power. I don't think you can sleep the HD on a 7100, I can on a 7500 but not on a 7100 to the best of my knowledge.

By sleep the HD do you mean spin down? (I too often misuse terms.) If so, Sleeper should be able to spin down the HD. I've used it as far back as an LCIII to spin down the HD.

Yes, I mean spin down. I used Sleeper once or twice but decided against it.

Clark Martin
Redwood City, CA, USA Macintosh / Internet Consulting

"I'm a designated driver on the Information Super Highway"

Message #32 - Posted 2001/10/04 - abuse

Clark Martin <clarkm@pacbell.net> writes:

Here are some numbers I collected:

7100:
Peak (Startup) 61 VA
Nominal 56 VA
Off 16 VA

And here is a 733MHz G4 (Digital Audio series) with 1GB RAM, 2 60GB IDE disks, a SCSI card, GF2 video and an Apple 17" flat panel monitor -

Peak (Startup) 168 VA
Nominal 144 VA
Off 19 VA

I must say this was a nice surprise, after reading the specs plus looking inside and seeing a massive heatsink my impression was it'd be a lot more of a current sucking hog than it is.

Billy Y..

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