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

Newer servers are now based on multicore processors that enable a single
processor to perform multiple separate tasks simultaneously, run multiple
applications on a single processor, or complete more tasks in a shorter
amount of time. Chip manufacturers claim that multicore processors can
reduce power and heat by up to 40 percent.
Embedded cooling uses the Liebert XD cooling infrastructure to deliver
high-efficiency cooling directly inside the rack. This approach brings cooling
even closer to the source of heat and allows the cooling system to be opti-
mized for a particular rack environment. An example of how effective this
approach can be is the CoolFrame system from Egenera and Emerson
Network Power. This system can prevent 20 kW of heat from an Egenera
BladeFrame system from entering the room by removing the heat before it
leaves the rack.
Chip-level cooling takes this approach to the next level by helping to
move heat away from the chip. As embedded and chip-level cooling solutions
are deployed, a highly efficient three-tiered approach to data center cooling
will emerge. In this approach, heat is effectively moved away from the chip
and then cooled in the rack, with stable temperatures and humidity main-
ptg
tained by room air conditioners. These developments are not expected to
reduce data center cooling requirements. Instead, they will result in an
increase in the amount of computing power that can be supported by a par-
ticular facility. As a result, the efficiency improvements made today will con-
tinue to pay dividends well into the future as these new developments enable
existing facilities to support densities that are not possible today.
The cooling system represents a significant opportunity to improve effi-
ciency. In many cases, relatively simple and inexpensive changes—such as
improving room sealing, moving cables or other objects that obstruct airflow,
or installing blanking panels—can pay immediate dividends. In addition,
new technologies, such as variable capacity room air conditioners and sophis-
ticated control systems, should be considered for their impact on efficiency.
Finally, supplemental cooling systems provide a response to increased equip-
ment densities that can increase the scalability and efficiency of existing cool-
ing systems.