A discussion of power usage effectiveness (PUE) and how this ratio is used as a measure of efficiency for data centres and computer rooms with IT equipment

1. WORK SMART
Power Usage Effectiveness – PUE
Reducing energy costs in your data centre
Oct 2011
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2. The need to measure Data Centre power
The energy bill is the largest single
item in the “total cost of ownership”
of a Data Centre.
Data Centres can use as much as
40% of the total energy costs in a
business (source: a London bank)
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3. What is PUE?
PUE = Power Usage Effectiveness
PUE provides an industry standard ratio to measure
the efficiency of the power used in a Data Centre
PUE = Total Facility Power
IT Equipment Power
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4. Making sense of PUE
A PUE of 2 means that the Data Centre
uses twice the power needed to run
its IT equipment
Example PUE = 2
– for every 1kW supplied, 500W is used by the IT equipment
The most efficient Data Centres now have a PUE of
1.2, though the industry average is around 2.
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5. Where is power used?
Total Facility Power Electrical
Auxilliary IT
UPS
Infrastructure
Cooling
External CRAC’s
Chillers
IT Servers
IT Equipment
By careful design, planning and operational practise data
centre teams can make energy savings, reduce PUE to a
minimum and maximize efficiency
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6. Reducing PUE
Measure – AIT’s Data Centre Audit
enables you to understand power usage
and provides recommendations
Optimise – AIT helps you optimise power, cooling and
server efficiency, enabling you to make instant savings
– Typical efficiencies: modern UPS, hot aisle separation system,
electrical loading, temperature optimisation etc etc
Monitor – AIT can installs and support Data Centre
Infrastructure Efficiency (DCIM) tools to enable to
monitor and further trim costs
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7. Effect of reducing PUE
PUE = 2 PUE = 1.2
Industry average Best in class
10% 1% 1% 6%
1% 3% 9%
IT
Cooling
50%
36% Lighting
83%
Aux
UPS
Reducing PUE dramatically improves IT efficiency
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8. Next Steps
Call AIT on 8045 017 7017 (link)
Our Data Centre Audit (link) allows you to
- Reduce energy consumption
- Lower total cost of ownership
- Improve facility efficiency
Our DCIM tools (link) provide on going data
for further improvements
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9. Useful Links
Contact us
Data Centre Audit
Data Centre Design
Data Centre Infrastructure Management Solutions
Data Centre Energy Management Solutions
Data Centre Cost Calculator
Network Solutions
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