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M i n i m i z i n g P o w e r U s a g e i n i m i z i n g P o w e r U s a g e

For instance, although reducing server power draws and minimizing PC power usage
seem obvious, you might decide to implement a plan where lighting automatically turns
off. You could get as small as directing laptop and cellular phone users to disconnect their
chargers from the wall when they’re not using them. Although there’s no device plugged
into the charger, the charger still sips at the electrical current.
Let’s talk about how your organization can study its power usage.
You should consider the costs involved with doing the testing yourself and what it
would cost to contract out the project. There’s no shame in hiring a professional to do the
heavy lifting. They are trained and experienced in this type of work and can give you the
results you want more quickly than you are likely able to do on your own—although you
can certainly do it on your own.
Servers PART II
To monitor power consumption yourself, you need to use power-monitoring software.
Without knowledge of where you’re starting, it’s impossible to tell how much of a problem
you have and to what degree your fixes are helping.
Several vendors offer tools that help monitor datacenter power. For instance, IBM’s
PowerExecutive provides the tools needed to monitor and manage power consumption
accurately. It can measure real-time power consumption and heat emission by individual server,
server group, or location. It allows for the optimization of energy use and the lowering of power
consumption when low utilization can provide cost savings. These power monitoring and
management capabilities are an important tool in achieving energy efficiency in the datacenter.
IBM’s PowerExecutive tool is shown in Figure 3-1.
With the results you get from your study, you should be able to do the following:

• Understand the datacenter’s thermal traits.
• Locate overlapping areas of cooling capacity. This helps because it shows where you can
place high-density or mission-critical equipment because of its ideal cooling location.
• Consider “what-ifs” with the placement of the datacenter

NOTE Don’t just stop with the servers. Don’t forget to upgrade transformers, uninterruptible
power supplies, and fans, among other devices.

Low-Cost Options
There are also some very low-cost solutions for checking power on your workstations and
standalone devices.

Kill A Watt
The Kill A Watt device is a US$25 product that you plug into the wall and then plug your
computer or monitor into the device. The result is that it will show you how much power
your device is using.
True, it’s not really practical in an environment with hundreds of workstations to run
around and plug in this device. However, assuming all the devices’ settings are the same
(or similar), you can measure a couple workstations and make some easy (and inexpensive)
assumptions about power usage.
More information about the Kill A Watt can be found at Link 3-1.