Sun Microsystems Netra t1 100, User And Administration Manual

Page: 31 / 154

Chapter 2 Operating Power and Cooling 9
Calculating the Power Requirements for
your Netra t1
A Netra t1 system containing two disk drives has an estimated power requirement
of approximately 1 amp.
TABLE 2-2
shows the estimated power consumed by the individual components in a
fully powered system (that is, in a system with a Power Supply Unit (PSU) operating
at 100% efficiency). However, when you are calculating the power requirements for
your system, you must allow for 65% PSU efficiency. To perform this calculation,
add the figures (from the third column of
TABLE 2-2
) for each component installed in
the system. Then divide the result by 0.65. Below are two examples.
Example A
The power requirement for a Netra t1 system operating at 65% PSU efficiency and
containing:
■
the 440 MHz CPU
■
512 Mbyte RAM
■
two 9 Gbyte disk drives
is calculated as follows:
TABLE 2-2
Estimated Power Consumption of the Components of the Netra t1
Component Estimated Power Consumption (at 100% PSU efficiency)
Base system 360 MHz 34.3 W
440 MHz 36.3 W
Memory (per DIMM) 0.21 W per 64 Mbyte
Disk drive 9 Gbyte/7200 rpm 11.0 W
18 Gbyte/10000 rpm 13.8 W
CD-ROM 3.2 W
PCI card Variable (max 25 W)
36.3 0.21 8
× ( )
11.0 2
× ( )
+ +
0.65
------------------------------------------------------------------------
92.28W =
SysAdmin.book Page 9 Friday, March 30, 2001 2:38 PM