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Seagate Cheetah 15K.5 SAS ST373455SS User Manual

Page 36

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Cheetah 15K.5 SAS Product Manual, Rev. E

ST3146855SS

in 3 Gbit operation

Typical power dissipation under idle conditions in 3Gb operation is 11.8 watts (40.27 BTUs per hour).

To obtain operating power for typical random read operations, refer to the following I/O rate curve (see Figure
8). Locate the typical I/O rate for a drive in your system on the horizontal axis and read the corresponding +5
volt current, +12 volt current, and total watts on the vertical axis. To calculate BTUs per hour, multiply watts by
3.4123.

Figure 9.

ST3146855SS (3 Gbit) DC current and power vs. input/output operations per second

CURRENT/POWER vs QUEUE DEPTH (SATA - 3.0GB)

Random 128 Block Write/Reads

0.000

0.200

0.400

0.600

0.800

1.000

1.200

1.400

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34

Queue Depth

Amp

e

re

s

0.00

2.00

4.00

6.00

8.00

10.00

12.00

14.00

P

o

w

e

r (w
atts)

5Vo lt A

12 Vo lt A

Watts

1

4

8

16

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