Slashdot Mirror

Never mind the trolls. And forget about our nominal leaders. They follow us, not the other way around. So, what are we going to do about climate change?

My house is a 70's era of about 2200 sq. ft., with a gas furnace, gas water heater (tank), and a 12 SEER A/C. The location is suburbia, and there's nothing I can do about that. It's be nice to be within walking distance of necessities, but that's just not happening. I've got us down to about $1500/year on energy costs. I understand that's very good. But I'd like to do more. I've already done most of the easy stuff. Most of the lights are CFLs. I set the thermostat at 82 in the summer and 70 in the winter. (I'd push that further, but the rest of the family whines too much when I do.) The house is well shaded by mature trees on the south side. But according to my calculations, half of our energy still goes towards heating and cooling. I have fuel efficient cars, and a plug in electric mower that I use as little as possible. I was very happy to bid farewell to the CRT.

I'm looking for paybacks of no more than 5 years, but that depends on price. I'll accept longer paybacks for cheap stuff. Ideas like putting in double pane windows filled with argon gas, roof vents, solar cells, solar water heaters, water recapture, and other expensive home remodeling notions simply aren't worth the cost. I heard that leaky ductwork can be a big waste of energy, but in this house, the ductwork is inside. The hallways have lower ceilings than the rooms. Anyway, it's a poor quality cookie cutter home. Hate to spend money on a piece of crap house. But if a bit of remodeling isn't worth doing, then knocking it down and starting over sure isn't worth doing. There are other things. I have a few 80%+ efficient computer power supplies, and some of those green power strips that automatically cut the power to peripherals when the main computer is off. For convenience I leave a computer running all the time, however it takes only 20 watts. It'd be better if I could get power management working in Linux. Even at only 20 watts, automatic suspend to disk could be a big saver if only it worked. Replaced a 40 watt fluorescent light fixture with the new 32 watt kind when the ballast went bad.

In any case, I have the feeling that's all "small ball". As a whole, our houses are poor and our cities are oblivious to all forms of transportation other than the almighty car. It's exasperating how much low hanging fruit we are ignoring. Automobile aerodynamics is a big one. Why isn't the underside of every car nice and smooth? Because no one looks at that part of the car. Why don't we have skirts on the wheels? Because they look "ugly"! A huge saver would be the electric car. I'm impatiently waiting for decent batteries. Would like to see at least 500 km capacity on a 15 minute charge, and able to last several thousand cycles.

Precisely, and that doesn't take into account the energy it takes to produce a new machine. I needed a new switch recently so I replaced the one that wasn't working with a newer one that was more energy efficient. The switch itself wasn't that expensive, but as long as I was buying one it made sense to get one that's more efficient. Same thing when I needed a new power supply, since I was already needing to buy one, I went with a 80 plus compliant power supply. I doubt that it would've made sense to do so had I not already needed to get a new one anyways.

For the record, my system pulls 120 W idle, 230 running CoHOF, and 5 in S3. It is extremely overclocked and mostly older components which tends to skew things, but I'm looking to upgrade and wouldn't mind saving a few bucks in energy costs in the long term.

5 watts in S3 is pretty bad in my book. Disconnect all USB devices and check again what your S3 power consumption is. If it is still high, most likely the PSU you have is not efficient. It could also come from other things like the motherboard, but most of the time it is the PSU. If your system idles at 120w, and 230w during load, you might be able to run with as low as a good 350w rated PSU. For example if your current PSU was around 70% efficient and you replaced it with an 80% efficient one, then during load your 230w draw would drop to around 201w. But you'll have to check and see if you can find the efficiency numbers for your current PSU.

How do you tell how much power a component is going to pull before you buy it?

There's no single source, but there are some useful websites.

80plus.org
Silent PC Review They generally provide both noise and power consumption measurements in their reviews
Silent PC Review Forums More anecdotal but at this point it is still good data. Many users post their own tests and measurements on the boards. It helps you get an idea of what's achievable and what isn't. There are also some nicely compiled charts that combine data from difference sources. I find the numbers are sometimes inaccurate but not too far off.

Go here for a good list of Power Supply part numbers: http://www.80plus.org/manu/psu/psu_join.aspx

Power supplies on that list are tested for efficiency at 20% load, 50% load, and 100% load. If they pass they get the 80 Plus efficiency rating. Newer 80 Plus ratings bronze, silver, and gold were added which have even stricter efficiency requirements.

Also sizing your power supply for your needs is critical. If your system is only going to consume 100 watts on load there's little reason why you should be buying a 600 watt power supply. If you're going to buy 4 video cards and/or 6 hard disks, then maybe. But for your standard single cpu, single video card, and one or two hard disk machine, a 400 watt power supply or maybe even less (depending on video card and cpu) might be all you need. That's because efficiency tends to drop-off under 20% of the PSU's load. So if our system consumes say 80 watts idle, then 400 watt PSU would be more efficient than a 500 watt PSU.

Another thing you should be looking at are the listed amps for each voltage line the psu can support. For example let's look at the following two PSUs at newegg: CHIEFTEC GREEN CTP-350-12G 350W and SeaSonic SS-350ET 350W. Both are rated 80 plus so they're both efficient and both have two 12V lines. But if we look at the output specs the Chieftec has 11A and 14A for the 12V lines while the Seasonic has 17A for each 12V line. In fact, the Seasonic PSU beats the Chieftec on all output voltages except the 3.3V which it loses by only 1amp. In this case the PSUs are rated exactly the same, but I've seen cheaper high wattage models with crappier specs than PSUs rated 50 watts or even 100 watts lower. The total output wattage might be higher but if each line can't handle the fluctuations your system can crash or your PSU can fail (sometimes violently).

He didn't mention 80 Plus power supplies. Not only will you save power, your case will be cooler.

I have two computers and a couple of Kill-A-Watt meters, so here are the power consumption figures for my two home computers just for comparison:

My most power efficient computer at home is 1 year old and has a 1.83 GHz Intel Core 2 Duo processor, 2 GB of RAM, Windows XP and is hooked to a 20-inch LCD flat screen monitor. Not counting the monitor it uses 24 Watts. The 20-inch flat screen. monitor uses 40 Watts (or only 1 Watt when in the sleep mode). This is not a laptop computer, it is a very small desktop computer, but it does happen to have a very small motherboard which is normally used in laptop computers.

My other computer is hooked to the same keyboard, monitor and mouse through a KVM switch. I had room for more than one computer but not more than one monitor.

A 2-year old AMD-64 computer running Kubuntu Linux is my main computer, which I am using at the moment. It is a dual-core AMD-64 4200+ and is hooked to the same 20-inch LCD flat screen monitor. It is using 82 Watts at the moment, plus an additional 40 Watts for the monitor. It can use more power under heavy load. When the monitor goes into the sleep mode it's power consumption drops to only 1 Watt. The computer has 2GB of RAM and 2 large hard drives. It has a 380-Watt 80+ power supply that is over 80% efficient. I use Kubuntu 7.10 Linux and by default it has the AMD-64's Cool n' Quiet feature enabled which saves power by dropping the CPU's clock speed from 2.4 GHz down to 1 GHz when the computer is idle or not doing anything difficult.

By the way, it does use 7-Watts even when it is turned off.

• Kill-A-Watt meter
• What is an 80 PLUS power supply?

Yes, your computer is using quite a bit of power.

I built my dual-core AMD 4200+ computer a couple of years ago. It has a Gigabyte K8NS nVidia Socket 939 ATX motherboard, 2 GB of RAM and 2 hard drives. It also has a 256 MB video card which uses the nVidia FX5200 chipset. It's 370 Watt power supply has an 80+ certified energy efficiency rating. 80+ certified power supplies are designed to be at least 80% energy efficient when running at 20%, 50% and 100% of the rated load. I use Linux on the computer and have the AMD 64's Cool n' Quiet feature enabled which which drops the clock speed from 2.4 GHz down to 1 GHz during light usage to save power.

My other computer is a small book sized computer computer which uses only 23 Watts when idle (not counting the monitor). It has a 1.85 GHz Intel Core 2 Duo processor with 2 GB of RAM and Windows XP. One reason that it uses so little power is that it uses the same type of motherboard that a laptop computer would use.

Both of those computers are plenty powerful for the typical web browsing, word processing and checking my email that I do. Running both computers at once, 24 hours per day would not be much worse than leaving a 100 Watt light bulb on all the time. Of course I actually use the much more energy efficient CFL light bulbs instead of ordinary 100 Watt incandescent light bulbs.

• What is 80 PLUS
• Compact fluorescent lamp (CFL)

I look for the new 80 Plus rating whenever I buy a new power supply for a computer. The 80 PLUS performance specification requires power supplies in computers to be 80% or greater energy efficient at 20%, 50% and 100% of rated load. Many computers come with much less efficient power supplies. I used an 80 Plus rated power supply in the most recent computer that I built. On my slightly older computer, the power supply recently died and I replaced it with an 80 Plus rated power supply.

Another problem is the energy consumption of inefficient auxiliary equipment with transformers which consume power even when the device is off. Those cheap poorly designed external transformers are sometimes called "vampire taps." The Smart Strip Power Strip could probably help there. When the Smart Strip senses that you've turned your computer off, it automatically shuts off your peripherals, too, preventing them from drawing an idle current. It does that by sensing the flow of electrical current through the strip's control outlet.

By the way, I live in the U.S., where we use 120 volts.

What is 80 PLUS
Smart Strip Power Strip

I switched to more energy efficient computer hardware, but did not just suddenly go out and buy new computer hardware all at once. I waited until each item became semi-obsolete or quit working, then I replaced it with a more energy efficient replacement. Perhaps the author should have suggested that people do it that way.

There are other advantages besides just saving money. For one thing, during power failures, my computer can now run much longer from UPS power. There is at usually least one thunderstorm, every summer, which knocks out the electricity for an hour or more. There are also usually other thunderstorms that are so loud and close, that I pull the power plug and unplug from the Internet, to avoid damage. I can now keep on working longer from UPS power while waiting for the worst part of the storm to pass.

An energy efficient computer is also usually quieter, because less powerful fans can be used.

With my purchasing choices as a consumer, I am sending a message to manufacturers that energy efficiency counts. I do not want a 500Watt power supply and dual power hungry high-end video cards. By purchasing energy efficient products, I am telling them that I want good performance with minimal power consumption.

One thing that the author did not mention was 80 PLUS certified power supplies. They are much more energy efficient that many of the other power supplies. I used one of those when I built my latest computer from scratch. Like the author, I also use a Kill-A-Watt meter. I also save energy by using CFL light bulbs.

The Kill-A-Watt (and its competitors) are a handy item. I was surprised to find that my desktop PC was pulling 118W doing "nothing" and 139W when working pretty hard. Even more surprising, when I switched to Volt-amp mode, the numbers were 189 and 210 VA, respectively. My office is usually too hot anyway, so I figured that was a good excuse for a new power supply. I got an "80 Plus" power supply, and now "Hymie" pulls under 88W/89VA when slacking and about 95W/96VA breathing hard. The power factor correction isn't just a gimmick. The case is much cooler, and I unplugged several of the now-unneeded fans, saving a couple more watts. On top of that, my immediate desk area is more comfortable and quieter. See website http://80plus.org/ for more info on "80 plus" program.

Computers vary quite a bit in how much power they use. My dual-core AMD-64 4200 is currently plugged into a Kill-A-Watt meter and according to the meter it is using 81 Watts at the moment. It occasionally uses much more power for short periods of time during heavy usage. The 20-inch LCD flat screen monitor was using an additional 38 Watts when I last checked. When the screen goes blank into the sleep mode the monitor's usage drops to only 1 Watt.The computer's video card is an AGP video card has the GeForce FX 5200 chip set and 256 MB of video RAM. It also has 2 GB of RAM and two hard drives with a total of 500 GB of hard disk space. The power supply is a 430 Watt power supply if I remember correctly.

I also have an AOpen mini-PC with a 1.83 GHz Core2 Duo that only uses about 23 Watts, not counting the monitor. The monitor uses about 38 Watts. It is the same monitor that I mentioned above. I use a KVM switch to control either computer with just one keyboard, monitor and mouse. The AOpen computer does not use much power because it has a motherboard and other components that are similar to what would be used in a laptop computer.

I have not yet bothered to measure how much power is used by other external components such as the DSL router, the UPS, the KVM switch, the speakers or the occasionally used external hard drive.

I am not a technician, but the use of an efficient 80-Plus power supply would also help save power. The 80 PLUS performance specification requires power supplies in computers and servers to be 80% or greater energy efficient at 20%, 50% and 100% of rated load.

What is 80 PLUS

Another thing to consider when buying a power supply is to be sure to get one that is 80+ certified, which means it has more than 80% energy efficiency, ie wastes 20% or less electric energy as heat, thus reducing electricity waste and bills.
The 80 PLUS Program

You mentioned power supplies that use 35W when the computer is off. Just for comparison, my Kill-A-Watt meter shows that when my computer is off it uses 11 Watts. It has a several year old, fanless 350 Watt power supply that Antec used to make, which was supposed to be more efficient (and expensive) than most power supplies. I also recently used the meter on another computer which has a fairly new 80 Plus power supply, which also happened to be made by Antec and it used 13 Watts when it was off.

The power supply in one of they two computers meets the new 80 Plus power supply specification. According to a web page about 80 Plus: "The 80 Plus performance specification requires power supplies in computers and servers to be 80% or greater energy efficient at 20%, 50% and 100% of rated load with a true power factor of 0.9 or greater."

Some of the newer CRTs may not be as bad as the older ones. As I mentioned elsewhere, I recently hooked the Kill-A-Watt meter to my 19-inch Philips 109B CRT monitor which I no longer use and found that is was only using 64 - 84 Watts depending on the color of the background. I also have a 20-inch LCD monitor, that I now use instead, which usually uses about 40-41 Watts. Today, when I measured it, it happened to only be using 35 - 37 Watts depending on background color, for some reason.

When my 1 1/2 year old AMD-64 3800+ computer is booting up it uses a peak of 159 Watts. Once it has booted up, the processor sees that it is not being asked to do much so it drops the clock speed from 2.4 GHz back to 1 GHz to save power and is then only using 94 Watts at that point. Kubuntu Linux automatically enabled that feature which AMD calls the Cool n' Quiet feature. When asked to do something more demanding the AMD-64 processor jumps back to 2.4 GHz for as long as necessary. I once used an earlier version of Slackware Linux which did not seem to support that feature on the default kernel that they used back then. If I am not mistaken, I believe that the Intel Core 2 Duo may also have some kind of somewhat similar power saving feature, but I am not totally sure. The number of hard drives, PCI cards, amount of memory and type of video card would also have some effect on how much power my computer uses.

I am not an expert or a technician, but that is what I got when measuring power usage at home, on my computers, with a Kill-A-Watt meter.

There are so many questions to answer for this question that the real and true answer will never be known.

AMD runs better with no load, where Intel runs better with full load. So in this particular instance, do you have a server that's gonna idle 99% of the time(If so why are you not using a VMWare setup?) I'd expect a nice new server to be cranking out 100% usage for as long as I can keep it there.

You are correct that for every 1 watt of heat, it takes 1.5 watts(or sometimes even more) to remove the heat.... BUT the power supply is also relevant for 3 reasons:

1 The power supply does 'expend' energy that is basically lost(as heat).
2. This heat must be factored into the heat generation if you are taking into account the cooling.
3. Every power supply has it's own power efficiency curve. And size does matter(ladies?). I'll use 2 Seasonic's as examples because I own one myself:

-500W http://www.80plus.org/manu/psu/documents/Seasonic_ SS-500ET_500W_80PLUS_Report.pdf

-650W http://www.80plus.org/manu/psu/documents/Seasonic_ SS-650HT_650W_80PLUS_Report.pdf

Notice the most efficient curve peaks at roughly 50%. That means that if you are looking for pure efficiency, you need to know how much power your machine uses(at the outlet of the power supply) to determine how to make your system as efficient as possible. The 15-20% loss is mostly I(squared)R losses(heat loss). So you see size does matter. It may matter for 13% heat at 250W or 19% heat at 600W, but it DOES matter. The only true way to compare is to show watts consumed at the output of your power supply, not the input. If I were building a system for efficiency, I'll match my own power supply to my loading requirements.

The other thing to check out is performance and component cost. If your server is gonna be run at 100%(ideally your IT budget prefers this because you're maximizing your $), the Intel may be able to service more 'customers' at the same time than AMD.

Here's a hypothetical scenario:

I'm setting up project D. Project D will have to supply 10,000 customers simultaneously 24x7. I'm a big company and those server will actually have 10,000 customers serviced 24x7(this is only to provide static loading).

If I buy Intel servers I'll need 100 machines.
If I buy AMD servers I'll need 200 machines.

So if my Intel servers use 80W more power than AMD:

Intel Watts Total = 100 machines x watts used
AMD Watts Total = 200 machines x watts used

You could also say: Intel Watts Total = 100 machines x (AMD watts for 1 machine + 80W)

So if you need 100 Intel servers that draw an extra 80W of power each to service your 10,000 customers, but you need 200 AMD servers to service the same customers, which becomes more efficient? Suddenly your buying twice as many machines(so posibly higher startup costs for AMD), and I'm sure each of those AMD machines will draw more than 80W for each machine(remember the different between the AMD and Intel in my scenario is Intel is 2x more powerful for only 80W, so 2 AMD machines should be able to do the same work for cost of 1xAMD Watts + 80W to stay even with Intel for efficiency). But now you have twice as many systems that can fail, they are all highly loaded(which leans in intel's favor), more IT support will be required for those machines, more cooling for those extra machines, more space in a building somewhere(assuming you have the actual space), etc...

So, which setup was more efficient? In this case, Intel was. But if AMD's machines only drew 5 watts of power at full load, and their machines were 1/2 the cost, then maybe they'd be a better bet. I don't know about other people, but space in my building is at a premium. You can theoretically buy an infinite number of computers,

There are so many questions to answer for this question that the real and true answer will never be known.

AMD runs better with no load, where Intel runs better with full load. So in this particular instance, do you have a server that's gonna idle 99% of the time(If so why are you not using a VMWare setup?) I'd expect a nice new server to be cranking out 100% usage for as long as I can keep it there.

You are correct that for every 1 watt of heat, it takes 1.5 watts(or sometimes even more) to remove the heat.... BUT the power supply is also relevant for 3 reasons:

1 The power supply does 'expend' energy that is basically lost(as heat).
2. This heat must be factored into the heat generation if you are taking into account the cooling.
3. Every power supply has it's own power efficiency curve. And size does matter(ladies?). I'll use 2 Seasonic's as examples because I own one myself:

-500W http://www.80plus.org/manu/psu/documents/Seasonic_ SS-500ET_500W_80PLUS_Report.pdf

-650W http://www.80plus.org/manu/psu/documents/Seasonic_ SS-650HT_650W_80PLUS_Report.pdf

Notice the most efficient curve peaks at roughly 50%. That means that if you are looking for pure efficiency, you need to know how much power your machine uses(at the outlet of the power supply) to determine how to make your system as efficient as possible. The 15-20% loss is mostly I(squared)R losses(heat loss). So you see size does matter. It may matter for 13% heat at 250W or 19% heat at 600W, but it DOES matter. The only true way to compare is to show watts consumed at the output of your power supply, not the input. If I were building a system for efficiency, I'll match my own power supply to my loading requirements.

The other thing to check out is performance and component cost. If your server is gonna be run at 100%(ideally your IT budget prefers this because you're maximizing your $), the Intel may be able to service more 'customers' at the same time than AMD.

Here's a hypothetical scenario:

I'm setting up project D. Project D will have to supply 10,000 customers simultaneously 24x7. I'm a big company and those server will actually have 10,000 customers serviced 24x7(this is only to provide static loading).

If I buy Intel servers I'll need 100 machines.
If I buy AMD servers I'll need 200 machines.

So if my Intel servers use 80W more power than AMD:

Intel Watts Total = 100 machines x watts used
AMD Watts Total = 200 machines x watts used

You could also say: Intel Watts Total = 100 machines x (AMD watts for 1 machine + 80W)

So if you need 100 Intel servers that draw an extra 80W of power each to service your 10,000 customers, but you need 200 AMD servers to service the same customers, which becomes more efficient? Suddenly your buying twice as many machines(so posibly higher startup costs for AMD), and I'm sure each of those AMD machines will draw more than 80W for each machine(remember the different between the AMD and Intel in my scenario is Intel is 2x more powerful for only 80W, so 2 AMD machines should be able to do the same work for cost of 1xAMD Watts + 80W to stay even with Intel for efficiency). But now you have twice as many systems that can fail, they are all highly loaded(which leans in intel's favor), more IT support will be required for those machines, more cooling for those extra machines, more space in a building somewhere(assuming you have the actual space), etc...

So, which setup was more efficient? In this case, Intel was. But if AMD's machines only drew 5 watts of power at full load, and their machines were 1/2 the cost, then maybe they'd be a better bet. I don't know about other people, but space in my building is at a premium. You can theoretically buy an infinite number of computers,

Being able to put components to sleep is pretty much worthless if you want to run anything resembling a server. Hardware manufacturers need to focus less on sleep states, and more on making components consume less power while they're active.

A good first step is the 80plus initiative for power supplies. By increasing the power supply from 65-70% to 80-85% efficiency, you gain a decent amount of active power savings right off the top. If you care at all about conservation, make sure to check the efficiency rating of your next power supply.

The people at Intel and AMD have made great strides toward power efficient CPUs, which can scale back their clocks on-demand without noticeably hurting performance, but the real remaining problem areas are in video cards, RAM, and especially hard drives.

The ideal computer would consume almost zero power while sitting there doing "nothing," but be able to wake up at a moment's notice to handle requests from the user or the network. Power management should be hardware-based and completely transparent. ACPI is just a dirty hack that's becoming more useless as network accessibility becomes more important.

As others have pointed out, if you can find an obsolete laptop, and just dedicate it for your 24/7 applications, that's going to be by far the most energy-efficient solution.

Some people say a switching PS is most efficient if you run it near its maximum capacity, and others say it's most efficient at 50%.

For your mobo, choose something with integrated video, rather than using a video card.

One other guideline when purchasing a PSU:

Buy the smallest PSU possible!

Many people out there have "SUV syndrome" when buying a PSU and incorrectly assume that they need that huge 500w (or bigger) PSU for their PC. Unless you really do have a high-end gaming PC with a high-end graphics card and multiple hard drives, your computer will almost certainly normally use less than 200w peak, and more typically 75-150w.

What does happen with an oversized PSU is in order to build a PSU to handle high current, it's efficiency at low current drops significantly. Typically the efficiency of a PSU starts dropping pretty quickly below 50% capacity and even faster below 25% capacity.

Finally, you can also look for PSUs which are 80 PLUS certified. These PSUs have been independently tested to be at least 80% efficient at 20%, 50% and 100% loads with a power factor rating of at least 0.9 at those load points.

The Antec EA430 is part of Antec's EarthWatts series of PSUs which are all 80 PLUS certified.

Out of the other PSUs casualsax3 tested, the SilverStone SST-ST50EF is also 80 PLUS certified. I could not verify if the Seasonic S12-380 is 80 PLUS certified, but it does not appear to be so even though it is more efficient than the Silverstone in casualsax3's test. If the S12-380 is of the "S12 Energy Plus" series then it should also be 80% efficient. I wonder if Seasonic quietly started shipping Energy Plus S12s instead of the old ones...

You may be making a funny, but the power supplies used in computers can make a huge difference in how green they are. An example of good power supply design can be seen at the 80+ group's website. The specification basically boosts the requirement for efficiency from the 70s to the 80s along with adding active power factor correction (a huge boon for building owners as that prevents the need for giant capacitors in the basement to save money on electric bills). The cost savings for a machine that is on 24/7 with one of these new supplies makes it pay for itself in just under a year.

I bought a 550 watt Enhance power supply based off of the list of vendors from that website and have been supremely impressed with what I got. My power bill has gone down by a several dollars a month and my living room doesn't get quite as scorching hot. Also, given the build quality (far superior to any power supplies named after woodland herbivores) I have no doubt that I will be able to use this supply for years to come. All the latest fancy power connectors are included (24 pin atx, 8 pin +12v, PCIe, sata, etc) and intelligently laid out.

What's more, most server rooms have a power backup unit, which converts from AC to DC and back to AC again, just so that the computers can convert it back to DC. This is terribly inefficient just in terms of electricity, and it also creates a whole lot of heat, just so that we can air condition these rooms with huge air conditioners!

Solar panels can not only smooth the peak (peak AC use often coincides with peak solar output), but they can shade the building. You can also use them to shade your cooling towers & building transformers to pre-cool them. Another option--use high-efficiency power supplies and make your colo customers use high-eff power supplies. 80plus.org Here's a useful book I've used to cut my company's computer power load by almost 16%: High Performance Data Centers, published by Rocky Mountain Institute. High Performance Data Centers, published by Rocky Mountain Institute.

I'd like to add (even though it affects all the other points you make, especially the noise levels)

5)Efficiency - a power supply that is rated 80% or greater efficiency at 20%, 50% and 100% of rated load with a Power Correction Factor as close to 1 as possible (Check out the program http://www.80plus.org/www.80plus.org). The biggest things this gives you are less heat output, meaning less noisy fans, as well as a reduction in you power bill, saving you $$$.

That is simply not true, check out: http://www.80plus.org/ If manufacturers make power supplies meeting the 80% plus standard of efficiency, they will be rewarded with cash for every unit made! There are several power supplies available that already meet these high standards of efficiency. The cost is not significantly higher, and the payback in electricity savings is short if the computer is on 24 hours a day.