Beta
×

Welcome to the Slashdot Beta site -- learn more here. Use the link in the footer or click here to return to the Classic version of Slashdot.

Thank you!

Before you choose to head back to the Classic look of the site, we'd appreciate it if you share your thoughts on the Beta; your feedback is what drives our ongoing development.

Beta is different and we value you taking the time to try it out. Please take a look at the changes we've made in Beta and  learn more about it. Thanks for reading, and for making the site better!

IEEE Seeks For Ethernet To 'Go Green'

Zonk posted more than 7 years ago | from the stop-packet-waste-now dept.

Networking 166

alphadogg submitted a piece at the NetworkWorld site about the IEEE's efforts to introduce energy efficiency to Ethernet use. The group's Energy Efficient Ethernet group is looking into methods by which standards can be tweaked to encourage power savings. Current plans include ways to make computers 'choosier' about what level of bandwidth they're using. Idle systems would only run at 10Mbps, while email might draw 100Mbs, and scale up to 1000Mbps for large downloads and streaming video. The group is planning to discuss changes to the Ethernet link and higher layers. No restrictions are planned for device manufacturers, although the article suggests some companies might try to use energy efficiency as a competitive advantage. The EEE group estimates some $450 million a year could be saved via the use of energy efficient Ethernet technology.

Sorry! There are no comments related to the filter you selected.

Saving energy now (5, Funny)

jbeaupre (752124) | more than 7 years ago | (#17862750)

Seems they are saving energy by throttling bandwidth for the article. Any manage to read it?

Re:Saving energy now (2, Insightful)

jbeaupre (752124) | more than 7 years ago | (#17862854)

Nevermind ... I just had to try connecting 3 or 4 times. Interesting idea. Let's see ... throw out millions of PC's with integrated ethernet, replace them with new machines. Oh, guess they mean in a decade or so through normal replacement.

Re:Saving energy now (3, Informative)

skoaldipper (752281) | more than 7 years ago | (#17862960)

I did. The problem (FTA):

"One challenge is finding a way to make a PC or laptop network interface card (NIC) change gears more quickly -- "a couple orders of magnitude faster than auto-negotiation, to make the switch as seamless as possible," Bennett says. "Auto-negotiation runs at about 1.4 seconds and we're talking about -- just to start the discussion -- a millisecond of switching time."

So, why not just set NIC(s) to negotiate at the lowest speed first? Then throttle up gradually based on end to end transmission intervals. They talked about using buffers and NIC electrical consumption to handle the negotiation. I say, just start at 10mbps and negotiate up to Gig speed gradually, and make the firmware drivers allow one to turn that feature off/on and back to our current default. My simpleton mind must be overlooking something.

Re:Saving energy now (1)

AoT (107216) | more than 7 years ago | (#17863598)

I think the problem is that they don't want the throttling up to be gradual, they want it to change gears quick like.

Re:Saving energy now (3, Interesting)

Anonymous Coward | more than 7 years ago | (#17863460)

For broadcom Ethernet PHY chips, they use about 1W/port when configured as 1000BaseT (GigE). GigE require some heavy duty DSP filtering as well as driving 4 pairs of bidirectional transceiver. They would burn less power when they are running at 100BaseT which only to drive 1 pair of receive and transmit. Not sure if there are significant saving going down to 10BaseT as the number of transmit pairs and the DSP's are dominant.

While this might not seem a whole lot of power, when you are looking at Enterprise size (say a few hundreds to thousands ports) setup, there can potentially be savings at the few hundred watts to thousand watts range.

Acronym confusion? (5, Funny)

MECC (8478) | more than 7 years ago | (#17862770)

Once Apple adds the ability to negotiate EEE in Macs, they'll call it iEEE.

Re:Acronym confusion? (4, Funny)

mrfantasy (63690) | more than 7 years ago | (#17863208)

It's the IEEE Energy Efficient Ethernet Initiative.

Or, the IEEEEEEI.

Commonly pronounced "eye-six-N-eye".

don't you mean (0)

Anonymous Coward | more than 7 years ago | (#17863386)

eye sextuple E eye? Or did a joke just whoosh over me?

I have an idea (5, Funny)

Salsaman (141471) | more than 7 years ago | (#17862892)

Use more zeros and fewer ones.

Re:I have an idea (1)

skiingyac (262641) | more than 7 years ago | (#17863132)

Sorry to ruin your joke, but that would work if you used Unipolar Baseband Signaling [techtarget.com] (send 1 volt for a "1" bit, 0 volts for a "0" bit).

You could also use a light on dark color scheme instead of dark on light (i.e., the white background & black text most websites use) if your monitor uses less energy for darker pixels (which I believe some types actually do).

Re:I have an idea (1)

Code Master (164951) | more than 7 years ago | (#17864000)

And it would use half the bandwidth for the same bit rate compared to ethernet which uses manchester encoding. However, it doesn't provide synchronization.

Re:I have an idea (2, Informative)

skiingyac (262641) | more than 7 years ago | (#17864210)

If you really wanted to, you could include a sync preamble like is done in many wireless physical layer protocols (might negate any efficiency gains though), or use an encoding like is used in CDs to ensure you don't end up with too long a string of all 1's or all 0's that the clock drift/differences cause ambiguity (less efficient than no encoding, but possibly better than manchester).

Re:I have an idea (2, Informative)

ToxikFetus (925966) | more than 7 years ago | (#17863278)

On an open collector [wikipedia.org] data bus, '1's would actually uses less power since that is the high impedance state. The '0's pull down the current.

Re:I have an idea (1)

dfn_deux (535506) | more than 7 years ago | (#17864026)

You know what would be awesome? If people read the articles that they linked too...

Open collector BJTs (which are usually NPN) exhibits faster fall time and greater current handling capabilities than FET, but have other problems. One of them is that they consume a lot of power.

Possible problems

As mentioned above, open-collector devices can handle more current, but they also have higher current minimums for correct operation. Even in the "off" state, open-collectors have some few nanoamps of leakage current (the exact amount varies with temperature.)

Power over Ethernet Could Help (5, Insightful)

Kadin2048 (468275) | more than 7 years ago | (#17862910)

One of the easiest ways that the Ethernet people could encourage energy efficiency would be by promoting greater use of Power Over Ethernet. By moving networked devices away from each having an individual wall wart, which are typically inefficient (as well as inconvenient), PoE lets you concentrate the AC to DC conversion in one place, for greater efficiency. As long as you don't have terribly long cable runs, I think there would be a significant net savings overall.

The number of networked devices people are going to have in their homes is only going to grow. I think a big segment could be in "Micro NAS" devices, basically single HD boxes that plug in to a home network and add storage that's accessible from any computer in the home. They're smaller and cheaper than RAIDed NAS solutions, but more convenient for people who have multiple computers than a FireWire or USB2.0 hard drive. And then you have routers, WiFi APs, network cameras, set-top-boxes for playing back video and audio, etc. All of those light-draw devices could be powered over the network connection instead of each having a wall wart.

Re:Power over Ethernet Could Help (5, Insightful)

GigsVT (208848) | more than 7 years ago | (#17862926)

Running power over tiny 24 gauge wires is very inefficient too. Try again.

Re:Power over Ethernet Could Help (1)

Namlak (850746) | more than 7 years ago | (#17863148)

Running power over tiny 24 gauge wires is very inefficient too. Try again.

If the current draw is small enough, there is very little power wasted. If the current draw was high enough to waste significant power, the wasted power would be turned into heat in the wire - how hot do you really think PoE wiring gets? Not much heat == not much power wasted. Now compare that to a wall-wart - even when disconnected from a load, they get warm.

But to the original poster's point - the vast majority of network equipment is already powered externally - PCs, switches, routers, etc. PoE is not going to power devices like that and what's left over (access points, etc) is probably not significant.

Re:Power over Ethernet Could Help (4, Informative)

NekoXP (67564) | more than 7 years ago | (#17863352)

Just because it doesn't generate heat doesn't mean it isn't losing power. The energy wasted in relation to the power on the cable is probably quite high (DC doesn't travel well, that's why wall power is AC remember) compared to just wiring up wall sockets and using warts or switching PSUs.

You're just transferring the wall-wart to another room though, and making the loss over the cable add to the power inefficiency. Imagine the extra airconditioning provision the room with the new site-wide AC-DC converter will need :D

PoE is a clever way to power devices that are in hard to power places (where you can wire a network using a thin cable but far away from a power socket) and keeps devices cheap (no need to do anything but DC-DC conversion from PoE to components) but it's not any better energy-efficiency-wise.

Can't this IEEE stuff they're talking about simply be built into drivers? I know my laptop ethernet (Intel) has the ability to scale down the ethernet speed when the battery is in use, or during standby and so on. Would it cause too much trouble to have the driver anticipate and schedule a renegotiation on a power source change or based on activity? Why would ethernet vendors need to be involved if it was simply a driver 'problem' - apart from having to write drivers that do it for their hardware (which most of them DO already).

Can't we have a sysctl or a sysfs tweak in Linux/BSD/whatever to demonstrate it and see if it even helps? Does networking hardware at the other end (for instance a 32-port Cisco switch) actually use less power if half it's ports are at 10mbit rather than 100mbit?

Can't we do this with wireless? 802.11b etc. already has power calibration built in but could it pull it back when the bandwidth requirement isn't so high, saving battery life and not polluting the airwaves with high powered chatter? My card uses the same transmit power whatever the state of the laptop is..

Re:Power over Ethernet Could Help (5, Informative)

Shakrai (717556) | more than 7 years ago | (#17863492)

(DC doesn't travel well, that's why wall power is AC remember)

This is a very common misconception. Low voltages don't travel well because you need more current (i.e: amps) to carry the same amount of power and this requires bigger wires. The main reason your wall power is AC is because it's easier and cheaper to build transformers for AC that convert high voltages (for distribution) into low voltages (for usage).

DC is actually used in electrical distribution. It's known as HVDC [wikipedia.org] and it's actually more efficient then AC because it doesn't have to contend with capacitance issues.

Re:Power over Ethernet Could Help (1)

drinkypoo (153816) | more than 7 years ago | (#17863572)

DC is actually used in electrical distribution. It's known as HVDC and it's actually more efficient then AC because it doesn't have to contend with capacitance issues.

While you are correct, we're talking about devices that tend to take 24V at the very most (I don't think I've ever seen a wall wart that put out more than that, although I am sure they exist somewhere.) This is definitely not high voltage. Thus you need to have super-fat low resistance conductors to run the power around. It might be a way to save money in the long run, though.

Re:Power over Ethernet Could Help (1)

Shakrai (717556) | more than 7 years ago | (#17863654)

This is definitely not high voltage.

I never disagreed with that. I was only responding to the parents comments about DC not traveling as well.

Re:Power over Ethernet Could Help (1)

profplump (309017) | more than 7 years ago | (#17863624)

DC travels just fine, it's the low-voltage part that increases transmission losses. AC or DC, low-voltage power experiences greater tranmission losses than the same power transfer at a higher voltage.

The only reason that we have AC at the wall is because we didn't have a DC, solid-state equivalent of the transformer in 1900, and therefore it was difficult to create high-voltage DC power. It's fairly widely acknowledge that if we had access to high-voltage direct current tranmissions systems a hundred years ago we would have DC power at the wall today. See http://en.wikipedia.org/wiki/War_of_Currents [wikipedia.org] for futher discussion.

Re:Power over Ethernet Could Help (1)

Shakrai (717556) | more than 7 years ago | (#17863712)

It's fairly widely acknowledge that if we had access to high-voltage direct current tranmissions systems a hundred years ago we would have DC power at the wall today.

Sure about that? DC at the wall would be a boon for electronics and lighting but I don't think it would work as well for my fridge, air conditioner, lawn mower, fans or anything else with an electric motor.

The efficiency of modern AC motors (especially three phase ones) is pretty impressive, on the order of 90%. Could that be duplicated on DC?

Re:Power over Ethernet Could Help (1)

aix tom (902140) | more than 7 years ago | (#17864214)

Yep, big DC motors are not very good or efficient.

Another problem with DC motors are the brushes, which have to be replaced regularly on high-power ones.

For that reason, one of my jobs a few years ago was to figure out a way to replace hundreds of high-power DC motors in production lines (which were used because before modern electronics to change the frequency of AC the speed regulation of DC motors was simpler) with AC ones. They consumed about 75% of the energy the DC ones had to use, and were about half the size.

Re:Power over Ethernet Could Help (1)

profplump (309017) | more than 7 years ago | (#17864344)

Old, brushed DC motors are not efficient that's true. But modern brushless DC motors are essentially identical to their variable-speed synchronous AC motor counterparts in both construction and efficency. In fact, the variable-frequency drive that runs the variable-speed synchronous AC motor rectifies incoming power to DC in order to create the output waveform.

Re:Power over Ethernet Could Help (1)

profplump (309017) | more than 7 years ago | (#17864252)

Yes, I'm pretty sure. Check out the Wikipedia: http://en.wikipedia.org/wiki/War_of_Currents [wikipedia.org] or some of the companies selling products for in-home DC power: http://www.moixaenergy.com/about-us.asp [moixaenergy.com]

DC power works just fine for electric motors. Non-synchronous AC induction motors are not particularly efficient nor do they have any increased torque or power output over DC brushed or brushless motors. The only advantage I see in fixed-speed applications is that AC induction motors require less maintenance in application where DC brushless would be too expensive. Those devices exist, but they don't include your A/C, fridge, washing machine, dishwasher, or any other device that cost more than $20 or so.

Modern variable speed AC motors (i.e. 3-phase AC motors) require a variable-frequency drive controller, which rectifies incoming power to DC before creating the control waveform. Such motors could be run on DC power without any significant conversion, and with a net efficiency *gain*, as they would no longer need to rectify incoming power. There's essentially no difference in the physical construction of synchronous AC motors and DC brushless motors -- it's just a question of the control method and input waveform.

Re:Power over Ethernet Could Help (1)

huge (52607) | more than 7 years ago | (#17864188)

PoE is a clever way to power devices that are in hard to power places
It's also a clever way to save money as you only need to install one cable instead of two. For example consider a warehouse that needs a wireless network, why to install separate power cables for each access point when you can do PoE.

Re:Power over Ethernet Could Help (2, Insightful)

D4rk Fx (862399) | more than 7 years ago | (#17864666)

Can't we do this with wireless? 802.11b etc
Somehow I think Power Over 802.11b would prove quite difficult to implement....

Re:Power over Ethernet Could Help (4, Interesting)

p0tat03 (985078) | more than 7 years ago | (#17863218)

An idea I've always thought about is converting to DC supplies indoors. AC has an advantage in terms of long-distance transmission, but in this day and age a HUGE part of our electric use is in devices that require DC power. Hell, many of the things that run AC (like lights) can in fact run DC with nary a problem. It's always boggled my mind why we have a bajillion power bricks sitting around, each venting heat like mad converting AC/DC, when in fact we could have a much more efficient "main" transformer installed in the house that does it on a larger scale and feeds our devices directly.

I imagine this would be even more useful for heavy power using environments like server farms - imagine if you can do with the huge boxy PSUs in every single box and just have a unified DC power source that can FAR more efficient than what's in the average beige boxen.

Re:Power over Ethernet Could Help (4, Informative)

Kadin2048 (468275) | more than 7 years ago | (#17863416)



An idea I've always thought about is converting to DC supplies indoors. AC has an advantage in terms of long-distance transmission, but in this day and age a HUGE part of our electric use is in devices that require DC power. Hell, many of the things that run AC (like lights) can in fact run DC with nary a problem. It's always boggled my mind why we have a bajillion power bricks sitting around, each venting heat like mad converting AC/DC, when in fact we could have a much more efficient "main" transformer installed in the house that does it on a larger scale and feeds our devices directly.

I imagine this would be even more useful for heavy power using environments like server farms - imagine if you can do with the huge boxy PSUs in every single box and just have a unified DC power source that can FAR more efficient than what's in the average beige boxen.


It is a good idea; in fact it's such a good idea that people have been thinking about ways to try and implement it in datacenters for a while. Unfortunately one of the bigger problems is that most motherboards don't run off of a single voltage; they have +5, -5, +3.3, +12, and so on. There has been a push by some big server-farm operators, Google in particular, to encourage board makers to produce mobos that only require a single +12V supply, because then you could do exactly what you say: have a big AC to DC converter somewhere (probably running from a medium-voltage AC main) and then distribute the 12VDC around to the racks.

It was a Slashdot article back in September:
http://hardware.slashdot.org/article.pl?sid=06/09/ 26/2039213 [slashdot.org]

Re:Power over Ethernet Could Help (0)

p0tat03 (985078) | more than 7 years ago | (#17863790)

Excuse me if this is a dumb idea, since my understanding of electronics is fairly basic. But wouldn't it be easier just to have a high DC source voltage that is higher than any device requires (say, 15V?), then just use zener diodes to get the voltage down to whatever it is that the device requires? I've done this on a small scale for individual devices, the voltage is rock solid stable, but I'm not sure how this will work out when you're drawing 300W from the source.

Re:Power over Ethernet Could Help (2, Informative)

dattaway (3088) | more than 7 years ago | (#17864032)

just use zener diodes to get the voltage down to whatever it is that the device requires?

Using shunt regulation? Bleeding off what you don't use in the form of heat? That's worse than linear voltage regulators!

You don't have to do that though (1)

Sycraft-fu (314770) | more than 7 years ago | (#17863816)

DC-DC converters are fairly efficient and it doesn't really matter if it was on the mobo or a separate unit, you'd still need it. So you have a 12v (or maybe higher since there is less loss) supply all over and then have little DC PSUs inside your PCs.

Re:Power over Ethernet Could Help (2, Informative)

Ungrounded Lightning (62228) | more than 7 years ago | (#17864588)

It is a good idea; in fact it's such a good idea that people have been thinking about ways to try and implement it in datacenters for a while.

Actually the networking industry DOES do it that way. SPower supply to many routers (such as ALL the ones some major companies make) and other networking gear is redundant 48V DC - a standard for networking equipment dating from the days of relays. (Line powered units have extra line powered supplies to make the 48 DC.)

Not only that, but often the boxes don't have a per-box 48-to-whatever supply. Instead each blade requiring other voltages has its own switching regulators.

(This isn't just for efficiency - it's also for redundancy. A box power supply is a single point of failure for the box. Give each card its own supply running directly from the redundant power busses and if one fails all the other cards in the box keep working - meaning only the lines to that card are in trouble, not everything hooked to the box. You have to pull a card with a failing component to replace it anyhow - so if you want to cover the lines to it in case of card failure you need other redundancy anyhow. So single points of failure on a card are OK.)

Power requirements on modern ASICs, networking processors, and RAMs are getting higher, operating voltages lower (for better speed-power products) forcing higher currents, and switching DC-DC converter/regulators are getting more efficient. These days it actually makes sense to add an additional regulator near a major load so the power can cross a few inches of the PC board at a higher voltage and lower current, to avoid heating and voltage droop in the layer of copper that carries it. You're starting to see that in PC motherboards, too.

Re:Power over Ethernet Could Help (1)

profplump (309017) | more than 7 years ago | (#17863678)

I'll just copy and paste this from above, to help fight the bad science:

DC travels just fine, it's the low-voltage part that increases transmission losses. AC or DC, low-voltage power experiences greater tranmission losses than the same power transfer at a higher voltage.

The only reason that we have AC at the wall is because we didn't have a DC, solid-state equivalent of the transformer in 1900, and therefore it was difficult to create high-voltage DC power. It's fairly widely acknowledge that if we had access to high-voltage direct current tranmissions systems a hundred years ago we would have DC power at the wall today. See http://en.wikipedia.org/wiki/War_of_Currents [wikipedia.org] [wikipedia.org] for futher discussion.

Re:Power over Ethernet Could Help (1)

Diss Champ (934796) | more than 7 years ago | (#17863778)

The issue with doing DC instead of AC for stuff that can do DC, is the AC to DC conversion tends to muck with the phase a bit. No biggie for small stuff, but when you get to industrial sized stuff, dealing with that is an issue. By that, I mean you either take steps not to screw with phase, or you let the power company do it and pay them more for your power than if you do it yourself.
If every house was all-DC, the power company would have to set up to keep all that properly balanced more than they currently do for the net of the wall-warts. As the percentage of stuff on wall-warts grows, that may stop being true, but I'm guessing (I'm not in the power bussiness) that we're still not close enough that the power company would be real happy with it.
From an energy saving point of view, it would take more wiring, but having AC and DC plugs could be a savings if one could get the device people to standardize on one voltage they all wanted to use. Unfortunately, those wall-warts are not all going to the same voltage, and DC to DC conversion has losses just like AC to DC conversion, so if you just need a different wall-wart to get you to the RIGHT DC, all you've done is add an extra conversion step to the chain.

On an industrial scale of course for a server farm or whatever, a unified conversion is indeed a lot more attractive.

Re:Power over Ethernet Could Help (1)

dattaway (3088) | more than 7 years ago | (#17864186)

I believe you mean "power factor" and not phase. Its the clipping at the peak of the waveform, rather than the whole, that causes excessive transmission line losses. Motors often take a bite off the lagging part of the waveform while computers take a chunk off the leading edge of the power factor. This makes your transformer outside less efficient and transfer less power.

Re:Power over Ethernet Could Help (0)

Anonymous Coward | more than 7 years ago | (#17864216)

> AC has an advantage in terms of long-distance transmission, but in this day and age a HUGE part of our electric use is in devices that require DC power.

Looking at just the transmission line, given the same voltage, DC loses less than AC. AC plausibly loses more than DC the closer the transmission line looks like an antenna.

Re:Power over Ethernet Could Help (1)

zlogic (892404) | more than 7 years ago | (#17863484)

I have a router, a switch and a WiFi access point in different parts of my house. Each uses its own power supply that makes a noise and produces heat. I think using a single power supply for all of them is more than enough, especially if the PSU is a bit more expensive (and a lot more efficient).

Re:Power over Ethernet Could Help (1)

Ungrounded Lightning (62228) | more than 7 years ago | (#17864156)

Running power over tiny 24 gauge wires is very inefficient too. Try again.

At 48 volts you can push significant wattage through tens of feet of four 24-gauge conductors in two-conductor parallel and still be far ahead of wall-warts. (This is what the telephone companies do to power your POTS phone from a central office miles away - except they're going farther and only use half as many conductors.)

What gauge do you think the wires in their coils are, and how much is wrapped around the core to form the transformer? Then there's the eddy current losses, core hysteresis, and (when present) the rotten efficiency of their regulators (which are often class-A, burning off the extra voltage (times the load current) as heat.)

Any bets on whether the losses in just the thin wire from a wall-wart to its load - at maybe 3 to 12 volts - dissipates more power than a similar length of 2-paralleled 24-gauge CatWhatever running at 48?

Re:Power over Ethernet Could Help (1)

Profane MuthaFucka (574406) | more than 7 years ago | (#17863092)

Once again, the time is right to announce my idea - use a single big power supply to provide power to all your main devices. A single 500 watt power supply could probably run everything an average person would have connected to their system.

Ideally you could daisy chain devices to make running power to a stack of disk drives easier, for example.

Last time I mentioned this, I got a bunch of morons saying that there's no way I could run ten 10 watt devices from a single 500 watt power supply, because of the "power factor". Let's see if those guys speak up again. I think it's a damn good idea, and with a few standard adapters for various plug types you could hook anything up to it.

Re:Power over Ethernet Could Help (1)

Short Circuit (52384) | more than 7 years ago | (#17863290)

You mean like USB and Firewire powering attached peripherals?

The only thing left would be the speakers, monitor and printer. Not sure about the power usage of a monitor or speakers, but printers have powerful motors that have to be able to contend with things like paper jams. I've heard anecdotal evidence of laser printers consuming as much as a kilowatt. (Though for laser printers, that's largely because they need to melt the toner.)

Also, a power supply doesn't simply provide N watts. Its power capabilities are divided between several rails of different voltages. The cheaper power supplies put most of their capability in the relatively unused 3.3V rail. Most power draw today is in the 12V rail.

Re:Power over Ethernet Could Help (1)

Profane MuthaFucka (574406) | more than 7 years ago | (#17863638)

Something like that, but it'd just be a separate power wire for the bunches of low power devices that are powered from warts. Not big printers, but things like your 8-port network switch, your hardware firewall, your USB drives, USB hubs, wireless access points, DSL modems, and so on.

Also this power supply would provide 500 watts, Not 3.3 volts and 12 volts, because that's a computer power supply. This would be a peripheral power supply providing standard wall wart voltages such as 7.5, 9, 5, and 12 volts.

And I really do think that a 500 watt power supply ought to be able to power 10 10-watt devices, and I don't think it's really too hard to find a wire big enough to carry 100 watts of power. I say this because some objections last time I raised this idea was that putting two little 8-port ethernet switches on a single power supply would require at least 2 kilowatts, and would require a wire at least an inch thick to handle the current. Seriously, they said that.

Re:Power over Ethernet Could Help (1)

Short Circuit (52384) | more than 7 years ago | (#17863922)

Oh, now I see what you're talking about. I thought you were talking about something internal to the PC.

Some advice. Don't go with multiple voltages. Instead, use one voltage, and let DC-DC converters in the device take care of the rest. And make it a relatively high voltage, to reduce wiring requirements.

They use 48V in telecom equipment. I'd suggest going with that. It's just shy of where voltages begin to get dangerous. (50V)

Re:Power over Ethernet Could Help (1)

TheRaven64 (641858) | more than 7 years ago | (#17863298)

Yes, it's a good idea. This is what high-densitry electronic installations do (telecoms, Google, etc). Power distribution loss might be a problem, depending on the size of your house. You might want two or three DC supplies, rather than just one. I think 500W would drive pretty much all of the electronics I own though; the number's dropped a lot in recent years.

Re:Power over Ethernet Could Help (1)

Profane MuthaFucka (574406) | more than 7 years ago | (#17863672)

THANK YOU. I'm counting the wall-warts I have plugged in under my desk - I have 11 of them plugged into 4 power strips.

Everything currently running on a wart could be on a single DC power supply. I hate these warts.

Re:Power over Ethernet Could Help (1)

SuperStretchy (1018064) | more than 7 years ago | (#17863254)

Sadly.. its not quite that simple. In terms of power savings, not only is 24-guage wire extremely restrictive on the flow of electrons, but it would layer that power on top of the signal in PoE type 1- or put the power on the 2 unused pairs in type 2. I think I remember reading somewhere that loses are about 40% (15 to 9 amps) per run of cable. Not running at operational power also will decrease the life of the equipment.

Any sort of power savings (or losses) would be negligible. Ethernet also doesn't use a signaling scheme where 1's are 5v and 0's are 0v. Lastly- this type of power consumption is something that we're going to have to put up with- just like that $4 cup of coffee every morning on the way to work.

Re:Power over Ethernet Could Help (1)

optimus2861 (760680) | more than 7 years ago | (#17863926)

I think I remember reading somewhere that loses are about 40% (15 to 9 amps) per run of cable. Not running at operational power also will decrease the life of the equipment.

I hope you're missing a couple of decimal points in there - anyone putting 15A on a 24AWG wire is asking for an electrical fire to start. 15A is the maximum allowable ampacity for most insulation grades of 14AWG wire, and 24AWG has 10x the resistance of 14AWG (87.5 ohms/km vs 8.54 ohms/km).

Voltage drop depends on the current & length of the cable, but even a 25-foot run with just 0.5A of current works out to a 0.66V drop - unsuitable for anything below 24V (maybe 12V could get away with it).

Handy link for checking the numbers: http://www.powerstream.com/Wire_Size.htm [powerstream.com]

Re:Power over Ethernet Could Help (1)

SuperStretchy (1018064) | more than 7 years ago | (#17864112)

Good catch- meant to say watts. Fact checking shows 400 mA

Re:Power over Ethernet Could Help (1)

Matt_Bennett (79107) | more than 7 years ago | (#17863566)

The biggest problem is that POE is limited to 13W at 48V- you'll have to have some sort of converter in there. I don't think that you would have much problem powering small scale things like APs and cameras, but it doesn't scale up very well.

But I like my Network Neutral (-1, Offtopic)

Anonymous Coward | more than 7 years ago | (#17862916)

And email getting 100 poops versus video getting 1000 poops is not neutral...

Green (2, Funny)

truthsearch (249536) | more than 7 years ago | (#17862934)

IEEE Seeks For Ethernet To 'Go Green'

That's good because I'm really tired of the white and blue.

Re:Green (1)

karnal (22275) | more than 7 years ago | (#17863664)

You forgot BROWN!

and orange.

Shoot.

white-orange/orange/white-green/blue/white-blue/gr een/white-brown/brown -> 568b

Well Duh!! (5, Insightful)

eclectro (227083) | more than 7 years ago | (#17862968)

Another suggestion - Stop all the spamming. There must be a coal-powered powerplant's worth of electricity right there.

Re:Well Duh!! (1)

hotdiggitydawg (881316) | more than 7 years ago | (#17863190)

Whoever modded this Funny... interesting choice. Was that one of those Seinfeld-esque "its funny 'cos its true" moments?

Re:Well Duh!! (0)

Anonymous Coward | more than 7 years ago | (#17863848)

It's funny because it's (almost) like saying "Well, duh! Stop gravity."

Re:Well Duh!! (1)

hotdiggitydawg (881316) | more than 7 years ago | (#17864558)

Perhaps you missed my point. I'm aware it's a difficult-if-not-impossible task. I was alluding to truth behind it, in that if it was achieved it would certainly cut down on a huge amount of wasted energy.

Re:Well Duh!! (1)

Tony Hoyle (11698) | more than 7 years ago | (#17864084)

Even better.. round up the spammers and use them as fuel for the power plants.

Doubly green energy - less spam... more efficient networks, and an infinite fuel supply (we'll never run out of spammers).

hmmm, who's that behind the curtain? (0, Flamebait)

Stumbles (602007) | more than 7 years ago | (#17862992)

I smell, DRM, RIAA, MPAA, and a few others behind this and it has NOTHING to do with "energy efficiency". What better way for the *AAs to get more control of your box.

Re:hmmm, who's that behind the curtain? (1)

Manchot (847225) | more than 7 years ago | (#17863274)

Calm down. IEEE [wikipedia.org] is the electrical engineering professional organization. They are the ones who collectively decide on most of the electrical standards in use (e.g., IEEE 802.11g). They have no interest in bowing down to corporations.

What about the power supplies... (4, Interesting)

russ1337 (938915) | more than 7 years ago | (#17862998)

Sounds like someone is really starting at the wrong end. IMHO.

I'd estimate that power supply inefficiency chews up more than this proposal will ever save. If you spent your time making the power supplies of PC's, Switches, routers more efficient you'd probably have a greater impact. How about better efficiency in the FET's, transistors and amplifier circuitry? Last time I checked, my Ethernet looms didn't get that hot. (isn't it all about "(i^2).R"?. Heck turning off the light in the switch room probably does more to save power. Plus all the heat im my server room is from the servers, not the Ethernet. If your that worried, switch to fiber.

I thought the transfer of data at the physical layer was through the transfer of 'holes' anyway.

Re:What about the power supplies... (1)

gmack (197796) | more than 7 years ago | (#17863080)

Last I checked my switches were starting to generate larger amounts of heat. The GigE switches definitely seem warmer than the 100mbps were.

Re:What about the power supplies... (1)

Yartrebo (690383) | more than 7 years ago | (#17863086)

I'm not sure if this an Ethernet issue, but my router and cable modem are substantial (probably >10 W) sources of heat. Considering that they're on 24/7, I sure would like to cut that down.

Re:What about the power supplies... (3, Interesting)

zaf (5944) | more than 7 years ago | (#17863102)

Exactly. All the hundreds of devices independently converting AC voltage to DC all day long is far more power waste than what's inside the CAT5. Speaking of, whatever happened to the push for DC datacenters? As far as I can tell, there's still no widely-used DC standard as an option for most of the devices in a small-medium sized environment

Re:What about the power supplies... (2, Informative)

jaredmauch (633928) | more than 7 years ago | (#17863380)

When you're talking about larger switches and routers and not the cheap linksys/dlink crap most people call a "router, there was actually a good presentation [nanog.org] at NANOG last year. You can watch it(real video) from the link (and view slides). Most of the efficency in these larger devices has already been done. (obviously excluding that whole google + pc power supply discussion). Check it out if you are truly interested in this space.

Re:What about the power supplies... (1)

vidarh (309115) | more than 7 years ago | (#17864034)

And exactly how much influence do you think people manufacturing ethernet cards have on power supply efficiency?

You seem to assume that if these people weren't improving the power efficiency of ethernet they'd just pick some random different field. The world doesn't work like that.

It's not the power at the physical layer - (2, Interesting)

wsanders (114993) | more than 7 years ago | (#17864118)

- it's the power required to process the packets. More or less, a GigE card should need 10X (divided by some fudge factor that probably makes the real ratio closer to 2 or 3X) the compute power of a 100Mbit card. Processing GigE at full throttle actually takes quite a bit of CPU - we don't notice it much because most GigE interfaces have a TCP Offload Engine that avoids bogging down the CPU and bus.

So your TOE could easily have a variable speed CPU that basically goes to sleep when it can negotiate the physical interface down to 10Mbit, or whatever. SOunds pretty straightforward.

Question? (4, Insightful)

SnarfQuest (469614) | more than 7 years ago | (#17863012)

Does 100 (or 1000) really take that much power to download one "file", or is it the same amount of power used, just in a shorter time period?

Or is it power used while idle? Does a 1000 device comsume more power idling in that mode than a 10 device would?

Re:Question? (2, Interesting)

Ant P. (974313) | more than 7 years ago | (#17863262)

I think what they're proposing is clock frequency control for Ethernet chips, like CPUs have now. I read somewhere that the power consumption increases n^3 with the clock speed, dunno where that figure comes from though.

Re:Question? (2, Informative)

greed (112493) | more than 7 years ago | (#17864256)

It's the square of the clock speed; it comes from some math in second- or third-year Electrical Engineering.

It has an awful lot to do with line capacitance and inductance; you've basically got to "fill up" the line before you can see the signal change at the other end. (Be it at chip-level or network-cable-level.)

Which is why narrower fab processes and low-voltage differential signaling is so important in high-speed circuits; all those watts are heat that has to be dissipated. Narrower CMOS gates take fewer electrons to charge up. And by also reducing the voltage needed to see the signal change, you can reduce the impact of that clock speed increase.

But that also means the old, slower speeds with modern signaling could be run on nearly no power. Which we do; that's how the iPod and cellphones get smaller and runs longer each year. (Dropping analog support on a 'phone helps a lot, too.)

Measurable? (2, Insightful)

zaf (5944) | more than 7 years ago | (#17863050)

Does that much current actually go over ethernet transmissions? It seems to be that more power could be saved by more efficient power supplies in the switches than by wasting a lot of time and research in figuring a way to throttle link speeds. Does anybody have a value for the amount of electricity used for an hour's worth of data at 10 megabits as opposed to 1 gigabit?

It just surprises me that +/-5 volts over copper really makes all that much difference compared to all the other waste in the datacenter.

Also, what's the difference in energy usage for copper vs fiber links??

Re:Measurable? (0)

Anonymous Coward | more than 7 years ago | (#17863478)

Don't be surprised. The Democrats are in now control of Congress. Expect a lot of people, companies, and governments to be fashionably "green". The hope is that people - especially the government, but other entities as well - will give you more money (through taxes/tax breaks, or increased sales, or something like that) because you're pretending to be doing something grand to help the environment. Whether or not it actually does help the environment isn't even an issue here. (And if you point out something doesn't, expect some people to excuse it because it "helps raise awareness" of bigger problems.)

Re:Measurable? (0)

Anonymous Coward | more than 7 years ago | (#17863540)

They didn't say that the waste occurred on the wires. Presumably the bulk of waste occurs in the switches.

Re:Measurable? (3, Informative)

Matt_Bennett (79107) | more than 7 years ago | (#17863708)

Actually, it is pretty surprising how much current Gigabit takes- The output drives usually work in a current mode, and they draw 40mA per pair- since gigabit uses 4 pairs, that's 160mA on each end of a gigabit link. *But* the big difference is in what happens when the link is idling- 10mbit only puts through link test pulses, but 100Mbit and Gigabit both keep up idle patterns that are basically encoded strings of no information- this keeps both ends of the link ready to accept data- 10Mbit has to transmit a synchronization series of pulses to make sure both ends are clocking at the same rate. For 100 and gig, at least to the output drivers, they draw the same amount idling or transmitting at line-speed.

My Money Says... (0, Troll)

eno2001 (527078) | more than 7 years ago | (#17863072)

...it'll be Windows based only. The non-MS crowd will have to reverse engineer it in a country that doesn't make that illegal.

Re:My Money Says... (1)

TheRaven64 (641858) | more than 7 years ago | (#17863328)

Yup, just like all those other Windows-only IEEE standards like, uh... no, sorry, can't think of a single one.

Re:My Money Says... (1)

eno2001 (527078) | more than 7 years ago | (#17863494)

OK smartass... try and get a Broadcom WiFi device working in Linux WITHOUT NDIS Wrapper. What's that you say? You can't!? Score one for me and zero for the kid in the dunce cap. Trust me, I've been doing this for a while and am a hardcore Linux user with only one Windows system in a virtual machine at home. I know what I am talking about. The IEEE standard has nothing to do with the actual implementation as Broadcom and others continue to prove by not releasing the specs on their hardware.

Re:My Money Says... (1)

Manchot (847225) | more than 7 years ago | (#17863814)

In your original post, you said "it'll be Windows based only." Since the article refers to the IEEE standard, "it" must therefore refer to that standard. And, as both you and the grandparent noted, the standard has nothing to do with the implementation by unrelated companies, so you cannot blame IEEE for any Windows-specific devices.

They don't like orange? (2, Funny)

bkoehler (784923) | more than 7 years ago | (#17863114)

I see no reason to switch from 568B to 568A.

Weak article (1)

AndroidCat (229562) | more than 7 years ago | (#17863170)

It would have been nice if the article had broken down the network power consumption down into something useful like the number of Watts for a single 10/100/1000 Mbps port, instead they bury it under the total IT power consumption. In the end, when I have to weigh the cost of upgrading my PC vs the energy savings, I'd like useful benchmarks.

Re:Weak article (1)

cowwie (85496) | more than 7 years ago | (#17863506)

Seriously! They talk about the $8billion total IT power budget, and this is supposed to cut off $450million... nearly 18% of the total budget... by turning back port speeds on switches and PCs? Those are some bloated numbers to be throwing around without some type of quantifiable facts to back it up.

Beware of the over-complicators gloves maytee (1)

mr_stinky_britches (926212) | more than 7 years ago | (#17863224)

It seems to me that the energy savings would be more beneficial to whoever pays the bill on the huge server farms rather than individual "normal people" who have a small ethernet running at their house or small business and whatnot. I hope they will shift away from this and focus on another area where they can actually make a difference that would noticeably benefit everyone; I especially like the idea of improving power supply efficiency (which is a bigger problem that just ethernets, IMO). One way to do this would be to get devices running directly off of direct AC current. IIRC, you can avoid a 20% penalty hit incurred from during the conversion from AC->DC that you get with normal power supplies.

Beware of the gloves of the over-complicators [thedailywtf.com] :p

--
Wi-Fizzle Research [wi-fizzle.com]

How does it compare to fiber for power usage (1)

rhvarona (710818) | more than 7 years ago | (#17863320)

How does a typical gigabit ethernet cabling installation compare to the same network using fiber cabling in terms of power usage?

By any chance... (3, Interesting)

ivan256 (17499) | more than 7 years ago | (#17863370)

...is this group led by ethernet equipment vendors? Perhaps vendors who are unhappy with the recent decline in equipment upgrades since people aren't upgrading from gigabit or even to gigabit from 100mbit in a way that helps their stock price sufficiently?

It seems to me that, considering the number of ports active out there, they're talking about a tiny amount of savings per port for a total investment that could have a much larger effect if spent elsewhere.

Hell, I bet more power is wasted by the power supplies, overly conservative fan controls, uncleaned air filters, shorted out UPS batteries that should have been replaced decades ago, overpowered CPUs, and crappily written firmware of the currently deployed switches than is consumed by transmission losses.

Soooo that would make them the... (0)

Anonymous Coward | more than 7 years ago | (#17863376)

IEEE-EEE?

A greener idea! (1)

Kopretinka (97408) | more than 7 years ago | (#17863452)

Imagine fiber with green laser - how green is that!

I recall the first time I noticed ethernet power (4, Interesting)

erroneus (253617) | more than 7 years ago | (#17863486)

At an office I once worked, there were a lot of spare switches laying about after upgrading to 1000BaseT. They were considered "spare" or whatever, but there was a great many... so I sorta brought one home and mounted it into my rack and used it for a couple of months. The next two electric bills made me rethink how nice it looked to have a 24 port switch in my rack instead of that cheapy 8 port sitting on a shelf. It consumed a NOTABLE amount of power. Now, there were other things involved I'm sure... things like the changes of the seasons, global warming and all that. But when I brought the switch back to the office and went back to my cheapy 8 port again, I saw a change in my power bill.

If I ever decide to spend money on a nice looking switch, I'll be sure to reference the power draw of the units I review.

Re:I recall the first time I noticed ethernet powe (1)

drinkypoo (153816) | more than 7 years ago | (#17863632)

Yeah, I used to have a catalyst 5000 with two 12 port cards and two 48 port 10mbps cards. But I didn't want to pay the power bill so I sold it. Now I have three tiny 10 port 10Mbps switches around the house doing switching things. Sure, I don't get any management, or vlans, or what have you, but I'm not sucking down an amp just running cooling fans, either, let alone what it takes to run one of those bastards. And that's not even that big a switch!

Welcome to tech support hell (1)

IGnatius T Foobar (4328) | more than 7 years ago | (#17863520)

Meanwhile, far more than $450 million would be spent on IT support services, troubleshooting problems created by computers that keep changing their link speed.

Re:Welcome to tech support hell (1)

operagost (62405) | more than 7 years ago | (#17864366)

Not to mention that I didn't see anywhere in this article, a statement on how much less power a 10 Mbps connection uses over a 100 or 1000 over the same time period. I'll assume that the lower speeds will actually be used when network utilization is below 10%, so determining power usage over the time to complete an operation is probably not necessary.

Sounds like a money grab for "research" (0)

Anonymous Coward | more than 7 years ago | (#17863528)

"There's lots to take on with this effort," says Mike Bennett, senior network engineer at Lawrence Berkeley National Lab, and chair of the EEE Study Group.

Uh huh. Tell me how much a 1000 vs 100 vs 10 port uses up in electricity when IDLE, until that number shows to be wildly different this is nothin more than a scam to get more money for questionable research.

I have no idea where the savings could come from. They shouldlook into spreading more efficient caching mechanisms so that people aren't waiting for webpages to download, thus reducing their time at the computer.

Slashdot the Power Grid (1)

Ikoma Andy (41693) | more than 7 years ago | (#17863584)

Wow, that's awesome! Now when you get DDoSed and your power suddenly spikes above the level it's been the last three years, you start popping breakers!

Contradictory (0)

Anonymous Coward | more than 7 years ago | (#17863586)

So does this mean that the internet, created by Al Gore is in some way responsible for global warming? If we didn't have all of these computers accessing networks, forcing us to burn fossil fuels for power then maybe we would be about 1C cooler. Thanks Al - for everything!

Patch cables are now easier than ever! (5, Funny)

PainBreak (794152) | more than 7 years ago | (#17863718)

So a straight-through is: Green white / Green / Green white / Green / Green white / Green / Green white / Green Sweet. Crossovers then would be: Green white / Green / Green white / Green white / Green / Green / Green / Green white So much easier to remember! Thanks, IEEE!

Two methods (2, Insightful)

HomelessInLaJolla (1026842) | more than 7 years ago | (#17863784)

> idle or underutilized Ethernet connections more energy efficient

There are several ways to increase measured efficiency. Two of them include:

1) Load the network with verbose transmission protocols, junk, or spam such that more network cards have higher sustained traffic (quantity means more than quality from the usage point of view).

2) Increase the number of hardware exploits such that underused network adapters can be continually used by those who know of the hardware exploits (make the network adapters available to those who have convinced themselves that they need more bandwidth than they're willing to pay for)

This is _not_ a troll. :)

Windows Vista DRM Implementation Wastes Power (-1, Offtopic)

Ron Bennett (14590) | more than 7 years ago | (#17863936)

While on the topic of "going green", Windows Vista's DRM implementation, collectively, is likely going to waste more power...

Windows Vista requires much new hardware, drivers, etc for the strong DRM encryption, tilt bits, etc... nothing more than a power waster for the typical user; all that number crunching likely shortens hardware life too.

Has the IEEE examined the issue of DRM on power usage? ... if not, they should!

Ron

I'd rather that they got auto-negotiation working (-1, Offtopic)

multiplexo (27356) | more than 7 years ago | (#17863998)

than fuck around with this. Auto-negotiation still doesn't work properly, and I still see problems with it on good Sun gear connected to good Foundry Network switches, not just on cheap, consumer grade crap. I had enough problems with it screwing things up that I finally disabled it, well I didn't disable it. I just set all of my backup clients up so that they could auto-negotiate all they wanted to. Just so long as they autonegotiated GigE, full duplex.

Do my eyes deceive me? (1)

freeze128 (544774) | more than 7 years ago | (#17864506)

The group is planning to discuss changes to the Ethernet link and higher layers.
The first time I read that, I thought it said "The group is planning to discuss changes to the Ethernet link and hire lawyers."

Let me get this straight... (0)

AJWM (19027) | more than 7 years ago | (#17864538)

Okay, there's two things that could consume power in an ethernet connection: maintaining the circuit at a given voltage level (ie steady state), and switching the signal (ie, sending a bit, modulo whatever encoding scheme is used).

For a given chunk of data -- email, text message, video clip, whatever -- you have a certain number of bits which is going to require a certain number of signal switches, whether you do those at 10M/sec or 1000M/sec. So, no energy savings there.

You also need to keep the circuit open, regardless of whether or not you're sending a signal over it. (Unless you want to try syncronizing the connection times: "call me every 7 minutes past the hour" or something. Not very practical). No energy savings there either.

So how, exactly, do they figure this is energy saving? (If anything, the extra bits sent for negotiation make it worse, no?)
Load More Comments
Slashdot Login

Need an Account?

Forgot your password?