Power Play
Optimize data center energy use
Improve cooling, processor and server efficiencies to reduce power consumption.
by John Schmidt
Data center energy use has
become a mainstream issue for manufacturers,
data center managers and even legislators.
Data centers accounted for 1.5 percent of
all electricity use in 2005, according to
the EPA, and according to IDC, in 2010 there
will be an estimated 15.8 million servers in
the United States, triple the number that
existed in 2000.
The impact of this growth
has made the importance of optimizing the
energy used in data centers a primary issue
for manufacturers providing everything from
servers to structured cabling. As such,
understanding some of the new methods that
can be used to optimize data center
efficiency is important.
Gartner estimates that
only about 1 percent of the energy generated
to power a data center ever makes it to the
processor. Power loss in the
electrical-distribution network,
power-conversion losses and cooling reduce
the percentage of power that makes it into
the processors doing the computational work
of a data center.
Best practices, such as
hot aisle/cold aisle placement and hot aisle containment,
will improve efficiencies.
More efficient processors
reduce the heat generated relative to the
processing power. Advances such as
45-nanometer silicon and quad-core
processors can reduce the power consumed by
the processor. Intel cites a 44 percent
reduction in power costs when using
quad-core technology compared with dual-core
processors.
Server virtualization is
another area of innovation that can
positively impact energy optimization.
Server virtualization allows multiple
applications to run simultaneously on a
single machine, allowing consolidation and
reduction of servers. Idle servers still
consume a significant amount of power, so
maximizing the use of each server will
result in overall power reduction.
VMware, a maker of
virtualization software, provides an online
calculator that indicates virtualizing 30
servers can reduce the energy costs for a
data center by $20,000 per year, and will
reduce CO2
emissions by 266,282 pounds a year.
Approximately 50 percent
of the energy used within a data center is
consumed by cooling equipment. Technologies
that are more efficient at removing heat
from the server and server cabinets will
have a positive impact on the power
efficiency of the data center.
A logical first step is
to have a computational fluid dynamics
analysis performed on the data center. This
computer modeling can predict areas of poor
airflow, increased heat and wasted cooling.
Technology advances also
exist in the area of computer room air
conditioning itself. Traditional methods of
cooling consist of flooding a raised floor
with chilled air from computer room air
conditioner units. This method will tend to
cool the entire computer room, resulting in
wasted energy.
Best practices, such as
hot aisle/cold aisle placement and hot aisle
containment, will improve efficiencies. New
technologies drive cooling closer to the
intended point of use, the server. In-row
cooling is a concept that puts the air
conditioning units adjacent to the server
cabinet. This can reduce annual electrical
costs for air conditioning by 50 percent or
more for average rack power densities
greater than 6 kW when compared with
room-oriented cooling.
Poor cabling management
can restrict airflow by blocking air inlets
and exhausts. Excess cables that are not
removed and excess lengths of cabling that
are not properly managed contribute to
airflow restriction. Paying close attention
to cleaning up these areas, specifically
around active equipment, will improve
airflow and will also make the installation
easier to manage. Removing raceway systems
from the raised floor and positioning them
overhead removes potential air dams from
underneath the floor, thus improving the
airflow.
John Schmidt
There is no single
solution that will solve these energy
efficiency issues. Combined efforts with
regards to processor and server efficiency,
cooling and optimized airflow to reduce the
power usage will be necessary.
John Schmidt is senior product manager of business development for
TrueNet Structured Cabling Systems,
ADC, Minneapolis, Minn. Schmidt holds an engineering degree from the University of Minnesota and has 10 issued patents for telecommunications and network equipment design.
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