Tag Archives: energy star

Finally, proof positive that PUE is garbage.

Vern Burke, SwiftWater Telecom
Biddeford, ME

I’ve just been reading a piece about Microsoft removing fans from their data center servers and that having a negative effect on their PUE numbers. I’ve written on this blog before about the problems with PUE, now we have proof that it needs to be put out of it’s misery.

In a nutshell, PUE is the ratio of power consumed by the IT equipment of the data center, versus the entire power consumed by the data center. A PUE of 1.0 would indicate a data center where all the power is being consumed by the IT equipment. A PUE greater that 1.0 indicates a data center where a certain amount of power is being consumed by other than IT equipment, the biggest chunk of which is cooling.

The problem I’ve written about before with PUE is the failure to take into account the actual work being accomplished by the IT equipment in the data center. Throw in a pile of extra servers just simply turned on and idling, not doing anything useful, and you’ve just gamed your PUE into looking better.

The problem shown here is even more damning. Microsoft determined that data center energy consumption could be reduced by removing the individual cooling fans from its servers and increasing the size of the data center cooling system. Since the increase in power for the data center cooling systems is less than the power required for the individual server fans, the data center accomplishes the same amount of work for less total energy consumption, an efficiency win in anyone’s book.

The side effect of this is that, even though the total energy consumption for the data center is reduced, transferring the energy usage from the fans (part of the IT equipment number) to the cooling (part of the non-IT equipment number) makes the PUE for the data center look WORSE.

Gaming the metric simply made it inaccurate, which was bad enough. Any efficiency metric that shows a net gain in data center efficiency (same amount of work accomplished for less energy consumed) as a NEGATIVE is hopelessly broken. This also has the side effect of making a mockery of the EPA’s Energy Star for data centers, since that award is based directly on the data center’s PUE.

Misleading, inaccurate, and now totally wrong, this sucker needs to go where all the other bad ideas go to die.

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Thursday data center tidbits: boneheaded data center efficiency statistics and more!

First up today, we have a piece about the EPA’s Energy Star data center rating system. Proving the old saw about lies, damn lies, and statistics, we get:

“Of the numerous variables analyzed, only the annual IT energy consumption was found to be statistically significant in explaining the variation in energy use; data showed that facilities with higher IT energy consumption have lower PUE values, on average. The final regression model predicts a PUE value based on the IT energy.”

This has to be the most ridiculous thing I’ve ever heard. Data centers with high power consumption are expected to get better PUE? Based on what?

So, not only is the measurement a crock (PUE), the target the data center is measured against is conjured out of thin air and about as substantial.

Next is from a piece asking “Is virtualization cloud computing?“. We get this jewel from this reading:

“To continue this analogue, cloud computing can happen without virtualization. Certain hardware, operating system and even application clusters can deliver cloud services. ”

Cloud computing is an extension of virtualization, it’s not possible to separate the two and still have something meaningfully labeled as cloud computing. Sorry, go sit in the corner with everyone else who misuses the term cloud.

Email or call me or visit the SwiftWater Telecom web site for cloud computing services.


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The green data center, the EPA, Energy Star, PUE, and total cluelessness.

I’ve just been reading a post about the EPA’s new Energy Star rating for data centers. It’s astonishing when you see the EPA having this big a bozo attack.

The first item on the list is the use of PUE (power usage effectiveness) as the criteria for awarding the Energy Star rating (I have no idea what happened to the EPA’s EUE metric they were trumpeting just a few months ago). In simple terms, PUE is the total amount of power used by the data center vs the amount of power used by the IT equipment in the data center. The problem with this approach is that it doesn’t take into account the actual amount of work being accomplished for that power, so it actually encourages the deployment of idle and underutilized equipment to skew the PUE metric for publicity and marketing purposes. Not very green at all.

PUE can be useful for evaluating the effect of changes made to a single facility, but it’s worse than useless for trying to compare multiple non-homogenous data centers. It’s so easy to skew that any comparisons are not only misleading, they’re downright dishonest as well.

The really astonishing thing is to hear the EPA Energy Star manager claim that the Energy Star rating didn’t have to take into account climate differences due to data center location because they didn’t have any statistical effect on PUE. This is the most clueless thing I’ve ever heard.

I’m sure all of these major companies that have located data centers in cooler climates to take advantage of free air cooling to drastically reduce electrical consumption required to cool the data center will be shocked to hear this (free air cooling circulates cool outside air to remove heat without any requirement for chillers). All of the massive power savings trumpeted in the news lately must just be a myth. Keep on mind, reducing cooling power usage reduces the overall power usage of the facility, driving down PUE.

Even for legacy cooling systems, cooler outside air increases efficiency. The larger the difference in temperature, the easier it is for the cooling system to dissipate or sink the waste heat. This means less energy involved in removing the same amount of heat.

To say that these techniques have no statistical bearing on PUE flies in the face of the laws of physics and just plain reality. This isn’t just some theory, it’s being done and it’s being proven out.

I wrote a week ago that this process was going to be a real circus and it’s nice to see them bearing me out. Alexandra Sullivan, EPA Energy Star manager, and the EPA as a whole get an en mass award for Data Center Bozos of the Week. The bulk shipment of multicolored wigs and red squeaky noses is on the way.

Call or email me or visit the SwiftWater Telecom web site for hype (and bozo) free green data center and cloud computing services.


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Monday data center tidbits.

First up today is a piece about companies not giving their employees incentives not to do inefficient things in the data center. Incentives for not screwing up? That used to be called keeping your job.

Next is a piece about data center Energy Star ratings based on PUE coming in June. I’ve written before about how PUE is useless as a tool to compare different data centers and is ridiculously easy to manipulate. Let the shoveling of BS commence!

ps I notice the Energy Star process only talks about self entered data and no audit process to verify the data center is actually doing what they say they are. This should be entertaining.

Are you looking for cloud computing services, virtual servers, workstations, desktops, or file servers? Call or email me or visit the SwiftWater Telecom web site today!


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Greening the data center: The EPA gives us another crazy metric.

Today I’ve been readin about the EPA using EUE for Energy Star certification of data centers. Just when I thought these things couldn’t get any nuttier.

EUE in short is the amount of energy supplied at the supplying point vs the amount of energy used by the IT equipment. EUE (energy usage efficiency) is very similar to PUE (power usage efficiency) with two notable exceptions. PUE covers only electrical usage where EUE covers all energy coming in to the data center. PUE also only covers electrical power from the entrance to the facility, EUE covers the energy from the source.

So, how does this impact data centers? First, since this measures usage at the source, the data center gets penalized for losses in the power grid. Be ready to build your next data center right next to the generating station (not to mention any other required utility).

Second, now, all energy supplied is now counted. Using utility supplied water for lossy cooling? Prepare to get whacked for it!

Now, I’m not suggesting this is all a bad thing. This metric will drive the use of green techniques such as free air cooling and self generated power.

The biggest problem with EUE is exactly the same as PUE. The only sane measurement of efficiency is energy in vs work out. Both EUE and PUE totally ignore the amount of work being accomplished with the energy. This produces results that range from simply misleading to totally useless.

Can’ t we do better than this?

Vern, SwiftWater Telecom
data center, web hosting, Internet engineering