Posts Tagged ‘PUE’

Measuring Datacenter Transformations

Tuesday, February 9th, 2010

Most people uses the PUE (Power Usage Effectiveness) as a metric to measure how efficient is their data center. However, increasingly, the DCiE (Datacenter Efficiency) metric is becoming more and more accepted as the metric of measurement.

Both metrics were proposed by the Green Grid in 2007, as a means to estimate the energy efficiency of their datacenters and to compare the results against other datacenters as well as to determine if any energy efficiency improvements need to be made. (more…)

Comparing Cold-Aisle vs. Hot-Aisle Containment

Sunday, January 24th, 2010

One of the key contributing factor towards efficiency and energy savings in data centers is preventing the mixing of hot and cold air, i.e. better air management and distribution. This can be accomplished through a containment strategy. Some vendors have products which allows containment of a single individual rack, while others offers containment of a group of racks.  Whenever a discussion about containment of a group of racks, often we would hear about debates on the merits and virtues of cold-aisle versus hot-aisle containment and vice-versa.

Most of the time, many fail to realise that it is necessary to take into consideration the cooling architecture whenever we speak about containment. Both are closely related.

I’ve written a short paper providing a comparison of the two containment strategies across the 3 cooling architectures (room-oriented, row-oriented and rack-oriented). You can read the paper here: Comparison of CAC vs HAC.

Syracuse University Data Centre goes Off The Grid

Monday, December 7th, 2009

The latest news on the wire is that IBM has taken Syracuse University’s (SU) data centre off the electric grid. SU’s data center will be supported by tri-generation, which burns gas to provide heating, cooling and electricity in one. This is being touted as one of the world’s greenest with the on-site power generation system, liquid cooling and DC power.

In a statement released this week, IBM and Syracuse said that the $12.4 million (£7.5m) , 12,000-square-foot facility is set to become fully operational in January and will use around 50 percent less energy than an equivalent sized facility according to IBM. The computer giant, which is backing the data centre to the tune of $5 million, is also planning to build a Green Data Centre Analysis and Design Centre in 2010 to help other organisations who want to create similar facilities.

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Cityscape and Data Center floor

Friday, October 16th, 2009

It has been almost four days since I last blogged. Have been busy with a client in Tokyo.

ShibuyaThis photo is a view from my hotel room at Shibuya. On the top left, you can see Tokyo tower at a distant away.

Look carefully at the picture and you’ll see that in general, there are buildings which are 10 stories high, in the middle of smaller buildings and there are occasionally a few which are 20 or more stories high. And here I am, looking out of my hotel room window, on the 29th storey. This is exactly the same state that we most likely will observe in a typical data center floor. There will be racks with highly densed equipment, consuming upwards of 15kW or more power, and right next to it, might be a patch panel rack with a few layer 2 switches, which is lower density. Each row of equipment racks and each individual rack will have varying composition of density.

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Planning for a new Data Center?

Friday, October 9th, 2009

DC_imgEvery data center project begins with the business plan and business requirements in mind. This is fundamentally the starting point and the first building blocks of a data center project. An enterprise with intention to build a data center facility for their own internal use may have an easier time to establish and understand this starting point. But for a Data Center service provider offering co-location and hosting services, then it gets a little bit complicated.

In reality, regardless of how closely the initial design matches with the business requirements, in the long run, data center facilities rarely achieve the efficiency, capacity and operational targets defined in their initial designs. This is because a data center environment is never static and like a living organism, it is always evolving. In the day to day operations, there will be people / human traffic, periodic changes, expansions, upgrades, introduction of new equipment, de-commissioning of aged equipment, and other external influences. As time goes by, newer technologies, with possibly higher density equipment, requiring substantial incremental power and cooling capacity, will replace aged equipment. Pressures to maximize utilization and reduce costs, will lead towards consolidation of data centers into few locations, adoption of virtualization technologies, causing changes in operational procedures, etc.  All these are part and parcel of the evolution of a data center environment, and no matter how you strive to achieve an equilibrium, as soon as you think you have reached an equilibrium, the operating conditions will likely change again.

For Data Center service providers, who are like hotels, they will rarely know when their next customers will be coming through their doors, or what kind of equipment these customers will be hosting at their facility. How do you plan the design of a facility for such requirement when these requirements are not known at present day?

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Accuracy of measurement sensors & Chiller Efficiency

Wednesday, October 7th, 2009

I spent some time over the weekend reviewing ASHRAE’s latest document on Real-time Energy Consumption Measurements in Data Centers. It is quite a comprehensive book in explaining and providing guidelines on energy, power systems, air and hydronic measurements.

One of the interesting topic explained in this ASHRAE book was related to how accuracy of sensors may influence the efficiency of chillers.

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How do Dolphins sleep?

Tuesday, September 29th, 2009

Dolphins

Marine mammals like dolphins breathe just like us. But while humans can breathe even when our conscious mind is asleep, dolphins are equipped with a voluntary respiratory system and therefore must keep part of their brain alert to trigger each breath. To avoid drowning, it is crucial that marine mammals retain control of their blowhole, which is a flap of skin that opens and closes under the dolphin’s voluntary control. Although still a matter of discussion, most researchers feel that in order to breathe, a dolphin must be conscious and alert to recognize that its blowhole is at the surface. So, how does a dolphin sleep?

The bottlenose dolphin sleeps by shutting down only half of its brain, along with the opposite eye. The other half of the brain stays awake at a low level of alertness. This attentive side is used to watch for predators, obstacles and other animals. It also signals when to rise to the surface for a fresh breath of air. After approximately two hours, the animal will reverse this process, resting the active side of the brain and awaking the rested half. This pattern is often called cat-napping.

So, applying the same concept on data center facilities, how do we maintain and service the critical infrastructure components in our data centers without reducing the number of capacity units required to support the data center?

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PUE (part 2)

Sunday, September 6th, 2009

Following up on my previous post regarding PUE.  What does it mean for an organization to have a low or high PUE?

PUE = (Total data center facility + IT equipment power utilization / Total IT equipment power utilization)

where PUE is a ratio, e.g. a PUE of 1.5 means that for every 1kW of IT equipment (be it server, network devices, firewalls, etc.), it would require 0.5kW of power to keep the data center operating to maintain sufficient cooling, de-humidification / humidification, availability (UPS), etc. to sustain and house the said IT equipment.

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PUE (part 1)

Saturday, September 5th, 2009

There is a saying “what you can’t measure, you can’t manage”.

When it comes to the data center facility, the Green Grid recommended using PUE (Power Usage Effectiveness) as a metric to measure data center efficiency. PUE is quite widely adopted in the industry today. It was intended (and still is) to be a simple metric for data centers that is easy to understand and use, that enables DC operators and IT administrators to quickly estimate the energy efficiency of their data centers, compare the results against other data centers, and determine if any energy efficiency improvements can be made or if there are potential problems. The PUE metric – which is the ratio of a facility’s total power to the power being drawn by IT equipment – requires complete knowledge and understanding of each component in the data center and its power consumption.

However, if you would analyze the ratio carefully, you realize a catch. “Power being drawn by IT equipment” – this is a variable number. IT equipment’s power consumption varies from time to time, depending on their utilization. For example, a server with 10% utilization will consume less power than a server utilized at 90% level.

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