Tag Archives: eue

Wednesday data center tidbits.


First up this morning, we have an article quoting a Microsoft person pondering about why many data center operators havn’t adopted any of the current data center “efficiency” metrics. It’s simple, the Green Grid’s PUE (power usage efficiency) and the EPA’s EUE (energy usage efficiency) are both a crock, since they’re ridiculously easy to game. Any data center energy efficiency metric that measures anything except total energy consumed vs total useful work achieved is misleading at the very best.

Vern, SwiftWater Telecom

aurora resilient cloud service

Finally, smart efficiency measurement for the data center.


After having PUE and EUE foisted on us, I knew someone was eventually going to get it right. This article I just read is spot on for the right way to measure data center efficiency.

First, I’ll take a brief look back at The Green Grid’s PUE (power usage effectiveness) and the EPA’s EUE (energy usage effectiveness). PUE measures the ratio of power coming into the data center vs the power required to operate the IT equipment. EUE, the metric that the EPA is using to award Energy Star to data centers, measures the power all the way through the distribution grid from the generating station. Have a really efficient data center but you’re in a lousy place on the grid or a long way from the generator? You get a lousy EUE.

Both of these metrics are critically incomplete and that makes them ridiculously easy to game. Fire up a bunch of extra servers and just leave them idling and watch PUE and EUE come out great! Any efficiency metric that ignores how much actual work is being done for the energy consumed is worthless. This also leads facilities to erroneously being labeled polluters in the press. Polluting isn’t consuming lots of energy to get lots of work done, it’s consuming lots of energy to get little work done. Sort of like stating how much gas a car uses without saying how many miles it goes on that amount of gas, ridiculous.

According to the article, this software ties the value of the work being done directly to the underlying physical infrastructure supporting it. Finally, the last piece of the puzzle, not only from a power efficiency standpoint, but a business bottom line standpoint as well. Operating the data center inefficiently not only isn’t green, it kills the business economically as well (if you don’t want to go green for the sake of it being the right thing to do, then consider the effect on your wallet!).

The software authors say that “today’s power monitoring products focus only on the physical infrastructure, giving insight into how power is delivered to the data center but not insight into why it is being consumed”. They’re spot on, not only in terms of power monitoring, but the defective metrics data centers are being judged on.

Remember, efficiency is power in vs work out. If you’re not measuring both, you’re not measuring data center efficiency, period.

Vern, SwiftWater Telcom

data center facility engineering

Greening the data center : the simplest thing you can do …


Do you know what all the servers in your data center are doing? According to this article, most don’t and it costs.

With all the discussion about the merits and application of various green data center techniques (free air cooling, DC power, etc), sometimes the simplest things get lost in the mix. Getting rid of zombie servers is one of the easiest things to accomplish (if you’re angling for great PUE or EUE numbers, if you care about the bottom line, they need to go!).

What is a zombie server? Basically it’s a server that consumes resources without producing a significant amount of useful work. Remember, the true measure of data center efficiency is energy consumed vs useful work out.

So, where do zombie servers come from? Well, since we’re approaching Halloween, you might expect the server graveyard. In reality, zombie servers can be the result of retiring obsolete applications, hot spares that really have no need to be hot (or even spare), rogue servers, or just plain poor utilization planning. Note too that zombie servers can also lead to other zombie equipment such as NASs or now unused networking equipment, all of which consumes space and power in the data center.

So, how do you de-zombie-fy? You must get an accurate picture of the utilization of every piece of equipment in the data center. Start with pulling the plug on the complete zombies. Next, combine functions to decrease the amount of running equipment required. I know that people can have an emotional attachment to their servers, but this will provide a nice bump for the bottom line without impacting the users at all.

Do your part and boot the zombie freeloaders out of your data center today!

Vern, SwiftWater Telecom

server co-location and data center

Greening the data center : define “green” please …


Tonight I’ve been reading a commentary about green data centers. While I can’t fault most of the recommendations, I think the definition of green-ness is way off base.

Any measurement that attempts to define a data center as green or not green without taking into account the amount of work achieved by that facility is worthless. I’ve taken the Green Grid’s PUE (power usage effectiveness) and the EPAs EUE (energy usage effectiveness) both to task for this. Now I include blanket negative mentions of a facilities carbon footprint.

The problem is that none of these measurements tell you anything about how efficiently a data center uses the energy it consumes to produce useful work. Stating a facility’s carbon footprint without any reference to the work produced by the facility is dishonest as best. The worst part is, without that final piece of the equation, it’s impossible to use any of these metrics to compare different data centers (not that this stops companies from using these as a marketing tool or potential customers from demanding these numbers).

The fact is, data centers can get great looking PUE numbers, have tiny carbon foot prints, and turn out pathetic amounts of work for the energy they consume. Fill a data center with idle servers and I’ll give you a fantastic PUE with ZERO work being done at all! Consuming energy without producing work is NOT in my definition of being green.

Are these metrics totally useless then? Absolutely not. PUE is useful as an internal measurement of cooling efficiency. Improve cooling efficiency, power required to cool goes down, PUE goes down, and that’s a good thing. Carbon footprint can tell us useful things about the energy sources that supply the data center. Replace traditional power sources with green power such as solar or wind (points for power generation on site!) and your carbon footprint goes down for the same amount of useful work, and that’s not a bad thing either.

When it comes right down to it, the only reasonable measurement of efficiency is energy consumed vs work accomplished. You could even expand this to cover the whole system as energy generation efficiency vs energy delivery efficiency vs energy consumed vs work produced to cover everything from the utility power generator to the output of the data center. Now you have something that can be used to compare different data centers, apples to apples. This is what the EPAs EUE should have been.

Efficient power generation, efficient delivery, efficient use of the power to produce as much useful work as possible. This is that real definition of a green data center.

Vern, SwiftWater Telecom

Green data center metrics : It’s ugly …


I just picked up a tweet with a link to Sustainable IT, Green IT . There was one giant thing that jumped out at me:

McKinsey and Company estimates that less than 1 percent of the energy of a data center is actually used to run specific business transactions. The vast majority (up to 90 percent) of energy is consumed by idle computers and for cooling.

I’ve been stating right along that the hyped metrics, PUE (power usage effectiveness) and the EPAs EUE (energy usage effectiveness) measure entirely the wrong things to be useful. Any efficiency metric that ignores the amount of actual work being accomplished with the power consumed is not only terribly misleading, but is also subject to being manipulated (fire up a pile of idle servers and watch your PUE improve!).

So now we have a crack at a real number. Only 1% of consumed energy is going to real work. Frankly, that’s pathetic. Now you know what energy inefficient servers, underutilized servers, legacy cooling systems and inefficient cooling designs, and legacy AC power and UPS systems with multiple conversions through energy wasting transformers are costing you.

If people won’t go green because it’s the right thing to do, how about the hit to the wallet? It’s like shoveling money down a rat hole.

What are YOU going to do to stop throwing money away?

Vern, SwiftWater Telecom

data center facility engineering

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