Page 88 -

C C h a p t e r 3 : h a p t e r 3 : 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 59 59
M

FIGURE 3-7 Unused
Power-managed RAID
RAID only uses the drives
drive where data is
being stored and
the parity drive.

Used
RAID
drive PART II

Parity
drive

Buffer
drive

Power-managed RAID provides parity protection, but with only some of the RAID
disks actually turned on. When data is written, only the parity and associated data drives
are powered up. When data is read, only the disk being read needs to be powered up. This
is illustrated in Figure 3-7.
Nondisruptive and sequential read/writes are accomplished by staging the data to an
always-spinning drive, while the next drive is being powered up. The result is that your
organization can have hundreds of terabytes in storage in a single footprint.
Monitors
It’s no secret that computer monitors are power hogs. Even new monitors can consume
100 W of power while they are on. In sleep mode, they typically use 5 W or less.
Adjusting your monitors to automatically enter sleep mode after a period of nonuse is
a quick-and-easy way to reduce costs.
LCD displays aren’t necessarily less power hungry that CRTs. It depends on the model
and how much power it draws. It’s best to evaluate monitor power draws as part of your
feature comparison before you buy one.

NOTE A free tool to tell you how much power your computer monitors are using can be found via
Link 3-4.
Settings
The first place to start is by setting up your monitors to turn off after a certain period of
nonuse. However, you can make some subtle changes to your computers’ settings that can
reduce costs while they are turned on. Specifically, managing the colors on your monitors—
especially backgrounds—can save money.