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Building an Energy Efficient Datacenter?
asc4 asks: "The company I work for is a webhosting and colocation company. As our power utilization grows, we have begun searching for ways to make our datacenter more efficient. The biggest hit from the utility company comes in the peak usage charge, which penalizes (rather severely) for the highest sustained burst of usage during a billing period. Due to the nature of the colocation business, we can't control how much or when client devices use power, so I'm wondering: is there's something we can do at the datacenter level to help smooth out our power consumption, over the course of a given period of time?"
"In these days of hybrid cars, Energy Star devices, and in general more eco-friendly power consumption, it seems like there must be some products out there that can help make datacenters more efficient, as well. Could fuel cell technology be something to look into? Would flywheels or capacitors help? How about using more efficient AC units than what are available from the big names? What are others doing to reduce peak power consumption in high-drain datacenter environments?"
I have one of these (1.2GHz) and with 1 large HDD, encoder card, network, DVD etc - it idles at less than 20W and maxes at about 60 (encoding, playback, DVD all going, CPU 100%). Burst power when switched on seems to be about 72. This is less than the processor alone on a high spec box.
This will only work with non-CPU intensive operations. However IO seems to be pretty good on these boxes, so an IO bound server would probably not suffer too greatly using a VIA mobo.
We are in deep trouble, energy wise. There is no immediate solution (within the next 30 years) that can help us.
Bull. But Congress needs to get off their ass. The potential gains of energy efficiency are enormous with minimal cost.
The average mileage of US vehicles peaked in the late 1980s. Increasing mileage by only 1 MPG (techically feasible at minimal cost) would result in enormous savings, but the MPG standards haven't changed in decades. What's worse, as SUVs became popular, the standards for SUVs are even worse than for cars. And if your SUV is over 6,000 pounds (suburban, excursion, hummer, etc) then there are no standards at all.
All sorts of electric devices (TVs, DVD players, microwaves, etc) use a huge amount of energy (10-50 watts) when they are "doing nothing", waiting for you to hit the "on" button. Multiply by 10-20 devices in the home and 24x7 and you are looking at a huge electric bill. There is no reason for these devices to use more than 1 watt in standby mode. Start legislating some standards.
Start changing building codes for higher insulation values. Improve efficiency standards for fridges, washer/dryers and other appliances.
Some things are easier to do in the design phase. but something can be done now.
/. earlier this week, keeping the building cooler in the morning and warmer in the afternoon can drop your peek time costs.
First, pre-cool the room. There was a good article on
Second, install a solar power system. Kinda pricy, but if you have a large roof you can generate some solid power. And don't think that being in the north excludes you from solar power. Uni-Solar has a great sun index map showing what level of solar output and electrical output you can expect in any given area.
Third, going with solar, a battery array or some other type of power storage. By using the solar pannels to juice up the batteries, you can pull power from the batteries at peek time, but charge them all day.
Fourth, sub-teranian cooling. Once you get a little ways under the surface of the ground, the temperature becomes a pretty consistant mid/high 50's. Using sunken water tanks you can run 60 degree water through a radiator in your HVAC system. I know there are companies that can install these system but I can't recall any names off the top of my head.
Fith, solid state storage. If you can swing paying $50/gig as opposed to $1/gig for storage space you can dramaticly cut down on your both your cooling bill and your electric bill.But at $50,000 per ter vs $1,000 per ter, it's going to take a while to recoup the costs.
Sixth, custom server cases/cabinets. Traditional closets are great for cramming a lot of servers into a small area, but they about suck for heat management. You could fund a research project at any number of engineering schools to create a better storage solution.
-Rick
"Most people in the U.S. wouldn't know they live in a tyrannical state if it walked up and grabbed their junk." - MyFirs
Get a professional electrician in that knows about peak charges.
Older installations used to use giant flywheels, but not to limit peaks. They were used for power conditioning and limited power backup.
I'd do an extensive survey before trying anything else. Buy or rent a power meter that does logging and graphing. Check everything out for a month - each phase and the current draw on each phase, and current draw on each rack (each computer if possible).
Proper sequencing of cooling can drastically affect your power consumption. Never start your cooling motors when you're drawing a lot of power - motor startup is a huge peak. After doing a survey of your power needs you may be able to identify times when you can avoid turning the cooling system on which will lower your peak. For instance, before the daily peak, cool the data center down a few degrees more than usual. Then shut off one or more cooling system until after the daily peak. This can be tricky to correctly manage and implement, especially since it has to be automatic and failsafe.
Alternately, shop around for your power. check with a few competitive companies and see if they offer a better deal.
-Adam
Switch to natural gas to run the air conditioners. Your peak electricity hit is in the middle of the day when the air conditioners work hardest, but the peak natural gas hit is in the middle of the night when the exterior temperature is coldest. Price wise that works to your advantage.
Moderating "-1, Disagree" is simple censorship. Have the guts to post your opinion.
...and don't forget Sun, if you feel like paying $20,000 for an 8-core Ultrasparc T1 chip that uses less power than an Opteron. Windows not allowed though. But since the original question is probably talking about managing a datacenter full of customer machines (which you can't control, unless you lease them), I would imagine that just changing the way you do cooling would make a rather large difference. Have you considered piping heat from the racks to the outside through the roof, and using a high specific-heat fluid (say water/ethylene glycol mix) that could be prechilled to an extremely low temperature during off-peak times, then used in a radiator-type arrangement for cooling. I would say that sealing the sides of your rack and replacing the front and rear doors with liquid-cooled radiators/heat collectors should work quite well. If you can pre-chill the air entering the front of the machines, it will be cooler coming out, and if you absorb the excess heat coming out the back, less heat will enter the room, meaning your air conditioners won't have to work as hard. Other good option would be to duct the exhaust heat (if it is significantly above room temp) up and out of the building with a few smaller fans.
--That's the point of being root, you can do anything you want, even if it's stupid.
Can you honestly suggest that a shorter Ethernet link will consume less power than a longer one? Sure, there's a tiny difference in cable resistance. But the transmitting end is putting the same amount of energy into it either way, since it doesn't know the difference. Any that doesn't turn into heat in the cable will turn into heat in the receiving chipset. Hence, the same power draw.
You *may* have an argument on very long fiber links. If you can get away with a short-reach transceivers instead of long-haul, you might save a watt or two. But again, if it's the same equipment at either end, the cable length doesn't matter, because any energy that doesn't succumb to cable attenuation just gets dissipated in the receiver. Or in some cases, in an optical attenuator pad just before the receiver, used to weaken a very strong signal so it doesn't destroy a sensitive receiver.
In both cases, the energy actually transmitted through the cable is so infitesimal, resistive losses are negligible and they don't matter anyway, because the energy that makes it through isn't used by the receiver, it's interpreted, then dissipated.
Tell me again how using CAT6 cable on a 10Mb/s link is inefficient? Financially yes, the cable's expensive, but electrically, the signal doesn't care. Neither cable is going to heat up more than the other one.
That being said,
Power cables are another matter entirely! Since they carry lots of current, resistive losses, even in adequate power cables, are measurable and significant. Particularly in 48v DC environments, as compared to 120v or 240v AC systems. To offset this, the power conductors in DC distribution plants are usually appallingly thick. Still, with a thermal infrared viewer, you can find "warm spots" in your power system. Fuses and breakers will always be a little warmer than the cables that feed them, out of necessity. But your power cables should be as short and thick as possible, within reason.
I say within reason because you're still only looking at a few dozen watts throughout the entire datacenter being lost to resistance in power cables. Rewiring the mess to use shorter cables will cost you more in labor and downtime than it's worth, but designing it right from the ground up might be worthwhile. In the meantime, just turn off the lights when you're not using them.
The rule to follow would be "if it produces measurable heat, it's something to look at". Network cables don't. Power cables, power supplies, processors, chipsets, drives, and memory do.