R&M Data Center Handbook

www.datacenter.rdm.com
There are several key benchmarks for assessing the energy efficiency of a data center. They were introduced in
section 1.10. Here is some additional information:
Green Grid (USA)
PUE Power Usage Effectiveness
DCIE Data Center Infrastructure Efficiency
IEP IT Equipment Power
TFP Total Facility Power
Uptime Institute (USA)
The ratio of power consumed by the entire facility to
the power consumed by the IT equipment alone
The ratio of power consumed by the IT equipment to
the power consumed by the entire facility (=1/PUE, i.e.
the reciprocal of PUE)
The actual power load associated with all of the IT
equipment including computing, storage and networking
equipment
The actual power load associated with the data center
facility including climate control (cooling), power,
surveillance, lighting, etc.
SI-EER
IT-PEW
DC-EEP
Site Infrastructure - Energy Efficiency
Ratio
IT Productivity per Embedded Watt
The ratio of power consumed by the entire facility to
the power consumed by the IT equipment alone
The ratio of IT productivity (network transactions, storage,
or computing cycles) to the IT equipment power
consumption
Value derived by multiplying SI-EER with IT-PEW
The most widely-used benchmark is the PUE but caution is advised since the data used in the calculation is not
always comparable.
The table on the right is an approximate evaluation
from the study carried out by the German Federal
Environment Agency (UBA) in 2010.
"Good" PUE values are currently trying to outdo one
another on the data center market; there are even
values below 1, which seems hard to believe.
Ø PUE
Data Center Type 2008 2015 Green IT
Server cabinet 1.3 1.2
Server room 1.8 1.5
Small data center 2.1 1.5
Medium data center 2.2 1.6
Large data center 2.2 1.6
As discussed above, operational costs are usually many times higher than acquisition costs, the PUE of a data
center being a key factor. Below, expected acquisition costs are compared with energy costs, using a server as
example. Not included are the related data center costs for rack space, maintenance, monitoring, etc.
Server hardware acquisition cost 1,500.00 €
Life span
Power consumption (in operation)
4 years
400 watts
Hours per year 24 hr. x 30.5 days x 12 months = 8,784 hr.
Power consumption per year 8.784 hr. x 0.4 kW = 3,513.6 kWh
Power costs per kWh 0.15 €
Power costs per year 3,513.6 kWh x 0.15 € = 527.04 €
Power costs 1 year 4 years
PUE = 3.0 527.04 € x 3 = 1,581.12 € 6,324.48 €
PUE = 2.2 527.04 € x 2.2 = 1,159.49 € 4,637.95 €
PUE = 1.6 527.04 € x 1.6 = 843.26 € 3,373.06 €
Page 42 of 156 © 08/2011 Reichle & De-Massari AG R&M Data Center Handbook V2.0