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For the better part of the last decade, IT professionals have been using a metric called Power Usage Effectiveness (PUE) to measure data center energy efficiency.
But what exactly is PUE? And should you be using it to track energy efficiency in your facility?
Here’s what you need to know:
PUE is nothing more than a ratio that compares a data center’s total energy consumption to the energy that is consumed by its IT equipment. In other words, it’s a way of seeing how much power your servers are using, versus your lights. The ideal PUE for a data center is 1.0, while a reading closer to 2.0 indicates that for every kilowatt of electricity consumed by the equipment, another kilowatt is needed to power the facility.
PUE was first introduced back in 2006 by Green Grid, a non-profit organization of IT professionals. And despite the metric’s many shortcomings (PUE readings are highly prone to error and manipulation, to the point where it’s hard to take a reading seriously) the metric quickly emerged one of the most common ways to track data center energy consumption.
This has changed. In 2016, PUE was officially eliminated as an acceptable metric for data center power efficiency by the American Society of Heating, Refrigerating and Air Conditioning (ASHRAE) — a global society committed to furthering sustainable construction. This happened when ASHRAE updated Standard 90.1, which offers recommended requirements for efficient energy design in buildings.
ASHRAE recognized that data centers have unique power management needs apart from common commercial spaces. So, the group created standard 90.4P specifically for data centers.
The ASHRAE 90.4 standard takes many factors into consideration, such as operation, maintenance, design and construction and the use of renewable resources. What’s more, ASHRAE 90.4P defines the data center as a conditioned space, room or building that has an IT equipment load exceeding 10kW, as well as a power utilization factor of more than 20-watts per square foot.
As of right now, the data center industry is still in the process of moving from standard 90.1 to 90.4P.
“We worked very hard to craft this standard in a manner that does not stifle innovation in the data center industry while simultaneously offering criteria to help ensure energy savings,” stated Ron Jarnagin, chair of the ASHRAE 90.4 committee. “It is important to keep in mind that data centers are mission critical facilities where risk management is the primary concern.”
Perhaps most importantly, the standard introduces two new metrics: Mechanical load components (MLC) and electrical loss components (ELC).
Here at Server Technology, we maintain that the easiest way to track energy usage in your facility is to take an automated, real-time approach to management. Using the Sentry Power Manager (SPM) in conjunction with intelligent power distribution units will provide you everything you need to track and plan for power efficiency.
To learn more information, click here.
Google Data Center
It’s never a good feeling reading about a truly green data center, and then realizing just how far behind your own data center ecosystem is in its sustainability efforts.
Take Google, for instance. On September 14, Google announced a new commitment to achieving “Zero Waste to Landfill” in its data centers. As Google Technical Program Manager Rachel Futrell explained on the Google Green Blog, Google is striving to divert waste away from its data centers in a sustainable way. Six of its 14 sites are now achieving 100 percent diversion rates. Globally, Google is now diverting at least 86 percent of waste away from landfills. And Google wants to improve these figures!
“Sustainability doesn’t end with a really low PUE for our data centers,” Fuller stated.
That’s pretty impressive. But in a way, it’s like sitting next to the kid in class who is getting straight A’s and is volunteering for extra credit assignments. Your business, on the other hand, is using as much power as a small city.
We feel your pain.
PUE, in case you’re unfamiliar with the term, stands for power usage effectiveness. It’s a metric used to determine overall data center power efficiency. A PUE measurement of 2.0 means that for every watt of power consumed in the data center, an extra watt is deployed for power or resource distribution purposes.
It’s important to realize that Google has an average PUE of about 1.12, which means that almost all of its electricity is put towards computing. Most data centers hover closer to 2.0.
How is Google able to attain such a low rating? It’s simple: Google tracks and measures power consumption over time, and uses the data it collects to continuously reduce its footprint.
In other words, Google has mastered power management. And now, the company can focus on higher-level sustainability efforts without having to worry about being labeled a “green washer,” or a company that claims to be sustainable but cannot provide evidence.
Here’s the good news:
You can master PUE in your data center, too, with the help of Server Technology’s Per Outlet Power Sensing power distribution units (POPS PDUs) and Sentry Power Manager (SPM) platform.
Here’s how it works:
Server Technology’s PDUs can report total power draw within each cabinet in your data center. Power draw can be tracked in real time, and on a historical basis. This data can then easily be compared with your facility’s total power draw. Once sufficient data is collected and analyzed, you can then determine an appropriate course of action for reducing total power consumption.
SPM makes it easy to understand the metrics it collects through its versatile reporting system. Within SPM, it’s possible to set schedules for viewing metrics such as your carbon footprint and total energy consumption.
So don’t wait any longer to “go green.” Click here to get started.
Time flies as, once again, we reached the end of another year. It seems like just yesterday we were sharing with you ways to shelter your network equipment from soaring summer temperatures. Now, you should be preparing your data center to handle 2015.
You’ll want to make sure your data center is well-equipped to handle the multitude of power-related challenges that will arise over the course of the next year. Toward this effort, we recommendation that you keep the following three data center power resolutions:
Let your racks breathe: Do your cables have a stranglehold on your racks? If so, they could be preventing cool air from getting to your servers, which could lead to overheating and equipment failure. Cable congestion also leads to frustration and confusion for network operators. So make sure reducing cable congestion is high on your list of priorities.
Improve your power usage effectiveness (PUE): Like most data centers, you simply don’t have the budget to be hemorrhaging money on inefficient equipment. You should make it a point, therefore, to improve your PUE, which is a metric for quantifying how efficiently your data center uses energy apart from cooling and other forms of overhead.
Gain control over your infrastructure: Are you managing your data center, or is your data center managing you? If you feel like you’ve lost control over your data center equipment, it’s only a matter of time before you experience a catastrophe like sudden power failure or you reach network capacity. You need critical insight through a robust data center power managing program that will let you see critical power draw in real time.
Server Technology, a leading provider of data center power management solutions, has all of the tools that you need to fulfill these resolutions. So don’t wait until the new year to actualize your goals. Click here to get started today.
This is the third in a series of blog posts providing tips and tricks for answering common data center questions with the use of SPM. Last month, I gave some guidance on answering, “How do I predict when I will run out of power?” On the other hand, you can gain additional power overhead by improving efficiency.
Question: How do I find candidates for efficiency improvements?
It is easy to say that you should improve efficiency, but how do you know what your efficiency is today and how do you know if that can be improved. The definition of efficiency for any power component or system is simply power out divided by power in (ε=Po/Pi). This leads one to desire measurement of power at each stage of the power distribution chain.
- In the data center, efficiency has to be thought of a little differently. One of the issues with the method for finding efficiency (ε) described above is that the front-end transformer or UPS may be supplying power to more than the IT equipment. In that case, the standard way to talk about efficiency is to use the Power Usage Effectiveness (PUE) which compares the output IT power draw to the total facility power (PUE = PTOTAL/PIT).
- When it comes to the overall power distribution system of a data center, the power out (Po) can be taken as the total power of the IT equipment in the cabinet (PIT) which requires devices such as Server Technology’s POPS CDUs. In SPM, set up reports and trends of Cabinet Device Power to analyze how much power is used by any particular piece of IT equipment and when it peaks.
- For the data center power distribution system, the power in (PTOTAL) can be taken as the total power input of the first device in the chain. This is generally the transformer or UPS. SPM has an optional feature called Custom Device Template (CDT) which allows the user to input SNMP MIB OIDs into the system to directly poll those upstream devices.
- With the data available from (a) and (b) above, one can calculate the PUE of the system. For advanced analysis, some organizations are taking this a step further by identifying how much of the IT power is actually being used for business applications vs how much is wasted while running idle. This is often referred to as Data Center energy Productivity (DCeP) and is beyond the scope of SPM.
- With a method of polling distribution equipment for power usage, the question then becomes one of where inefficiencies occur.
- Most simple distribution equipment will have very low power losses, but active components such as on-board monitoring and communication circuits, any transformation circuits, and bad connections will cause power output to be less than the power input. Suspicious distribution equipment with measurement circuits can often be monitored using SNMP and the SPM-CDT feature. Then comparisons can be made with expected efficiency values for that particular equipment.
- When it comes down to the IT equipment, the manufacturers often provide efficiency data and expected power draw based on the design specifications. The Server Technology POPS CDU coupled with continual monitoring using SPM can provide the data center efficiency or PUE calculation with critical values. By watching trends of power and power factor over time for particular equipment, one can identify potential issues arising within the IT power supplies.
- Overall data center efficiency, especially in the form of PUE or DCeP, depends heavily on usage of the particular equipment. Often, power supplies for servers, network gear, and storage will run more efficiently when loaded more heavily. And, more importantly, unused equipment wastes power in idle states. Here again the Server Technology POPS CDU and SPM can help provide critical data in terms of power trending and a report on low usage power supplies.
- Once measurement data is collected for various points in the data center, the question of what can be changed must be asked. Armed with these answers, an ROI can be built to determine which course of action to take.
- Much of the efficiency analysis hinges on the design and operation of specific pieces of equipment. Identification of low performing transformation or distribution devices often begs the question of upgrading or replacing those devices. A direct analysis of ROI can be done by comparing the cost of energy used by the old devices to the expected reduced cost of the new equipment in question. As seen in (1) and (2) above, SPM is built to provide the bulk of power and energy data.
- PUE and DCeP can be improved by using existing equipment at a higher rate. This is typically done through a consolidation and virtualization project which removes the lowest performing equipment and moves application load to higher performing equipment. Use SPM to measure the effects of any changes done and to prove out the concepts.
- On shared IT resources, especially virtualized servers, the timing of application usage is often the wild card in maximizing PUE and DCeP. Using the equipment 24/7 at 90%+ is a great goal where batch processing is done during non-working hours. This is typically not seen, but one might be able to schedule certain equipment to be powered off during non-peak hours, thus boosting the live equipment utilization toward the goal. SPM can help with this through scheduling of outlet control and trending of device power usage.
- Another data center efficiency, PUE, or DCeP improvement comes from increasing temperature. In other words, reducing the power used to cool the IT equipment reduces the overall cost of running the data center. SPM helps with this by monitoring the CDU attached probes and can compare this data with power usage data in a trend format.
Freeing up lost capacity by improving efficiency can be a great challenge in the data center. For more information on methods for maximum efficiency, read our White Papers on the subject.