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The Greening of IT
22 How Companies Can Make a Difference for the Environment

maximum power when idle. IT organizations should turn off servers that
don’t appear to be performing tasks. If anyone complains, organizations
should look into whether the little-used application can be virtualized.
Check with your electric utility. Some utilities such as PG&E offer free
energy audits.

Manage and Measure
Many hardware products have built-in power management features that
are never used. Most major vendors have been implementing such features
for quite some time. These features include the capability of the CPU to
optimize power by dynamically switching among multiple performance
states. The CPU drops its input voltage and frequency based on how many
instructions are run on the chip itself. These types of features can save
organizations up to 20 percent on server power consumption.
Several companies offer green testing and measurement tools for the
data center. In 2008, Ixia released the IxGreen, which measures the
amount of power required to run components in the data center at vari-
ous performance levels. Miercom, a network product test center,
ptg
announced a Certified Green testing program. The Miercom program
tests products to challenge networking equipment suppliers to design
power-efficient network infrastructure. Cisco switches were the first to
receive the certification.

Cool
Many data centers might use hot aisle or cold aisle configurations to
improve cooling efficiency, but they can also make some small adjust-
ments. Simple blanking panels can be installed in server racks that have
empty slots. That’s a great way to make sure the cold air in the cold aisle
doesn’t start mixing with the hot air in the hot aisle any sooner than it
needs to. Organizations should also seal cable cutouts to minimize air-
flow bypasses. Data organizations should consider air handlers and
chillers that use efficient technologies, such as variable frequency drives
that adjust how fast the air-conditioning system’s motors run when cool-
ing needs dip.

Virtualize
Virtualization continues to be one of the hottest green data center
topics. Vendors have said current server utilization rates typically hover