How to Optimize the Energy Efficiency of Your Server (
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Energy efficiency in the data center is the hot topic of the day. We all want the fastest, most powerful servers for our data center. We want to optimize, virtualize and consolidate in the name of making our data centers more efficient and green. Here, Knowledge Center contributor Julius Neudorfer examines several key components that impact the total energy a typical server utilizes, as well as what it really costs to operate a server and how to optimize the energy efficiency of your server.
Everyone
is looking at their data center efficiency and trying to quantify it
and improve it. Of course, there are actually two separate groups
addressing it from different positions, the facilities team and the IT
group.
The facilities team is responsible for the power and cooling of the
overall enclosed space. The IT group is in charge of the servers,
storage and networking hardware. Typically, each side speaks to each
other as little as possibleexcept when they have reached the limits of
power or cooling (or both) in the server room or data center.
One group, The Green Grid,
was created by both the IT equipment manufacturers and the power and
cooling equipment manufacturers. The Green Grid has created, and has
been promoting, the Power Usage Effectiveness (PUE) and Data Center
Infrastructure Efficiency (DCiE) methods of measuring data center
efficiency.
While I won't delve into all the details of PUE calculations here,
the basic premise is that it represents the ratio of the total power
consumed (including uninterruptible power supply and cooling) by the
data center, including the IT load itself, divided by the IT load. A
simple example is that if the total load is 200 kilowatts (kW) and the
IT load is 100 kW, a PUE of 2.0 would result. While the PUE can vary
from 1.x to 3.x, a PUE of 2.0 is a fairly common operating ratio for
many data centers.
However, even these new measurement standards, oddly enough, do not directly address any IT equipment efficiencyonly
the power and cooling equipment efficiency. And, while this article is
not focused on data center infrastructure efficiency, it is important
for the IT department to understand and consider that for every watt of
IT equipment, the data center infrastructure requires additional energy
to support it.
Even the United States government, after spending a significant
amount of time and resources, has not been able to fully define and
regulate the power efficiency of the data center and the servers and IT
equipment (according to an EPA report to Congress in August 2007). It is still in the process and, according to the EPA ENERGY STAR Computer Server Stakeholder Meeting of July 9, 2008 in Redmond, WA, the first-tier rules are expected to become finalized in 2009.
In the rush to optimize, virtualize and consolidate in the name of
making our computing-related operations more effective and efficient
(and, of course, green), we have heard many server manufacturers
profess that their products provide the most computing power for the
least amount of energy. Only recently have the server manufacturers
even begun to discuss or disclose the efficiency of their servers.
Currently, there are no real standards for the overall energy
efficiency of servers.
There are several key components which impact the total energy a
typical server utilizes: these components are power supplies, fans,
CPUs, memory, hard drives, I/O card and ports, and other motherboard
components and supporting chip sets. These main components exist in
both conventional servers and in blade servers.
However, in the case of the blade servers, some itemssuch as power
supplies, fans and I/O portsare shared on a common chassis, while the
CPU and other related motherboard items are located on the individual
blades. Depending on the design of the blade server, the hard drives
can be located on either the chassis or the blades. In addition to the
aforementioned list, the operating system and virtualization software
will also impact the overall usable computing throughput of the
hardware platform.
Every manufacturer likes to claim that their product or platform is
the most energy-efficient. However, while each one may have a
particular sweet spot (for example, the chip set may be more efficient
with a particular operating system), overall they all utilize the same
basic components and are in the same boat when it comes to the power
being used by these components.
Of course, we all want the fastest, most powerful servers for our
data center. So, although energy efficiency (for example, green) is the
watchword, historically it would seem we only think about energy usage
when our power and/or cooling systems are maxed out and may need to be
upgraded. Normally, when we need to know how much power the server
requires, we turn to the name plate. However, it just represents the
maximum amount of power the unit could draw, not the actual power draw
in reality. Let's now examine what it really costs to operate a server.
IT Infrastructure 
