Seagate Cheetah 15K.4 SAS, Product Manual

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Cheetah 15K.4 SAS Product Manual, Rev. B 31
6.3 Power dissipation
ST3146854SS in 3 Gbit operation
Typical power dissipation under idle conditions in 3Gb operation is 14.34 watts (48.93 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 corresp5
volt current, +12 volt current, and total watts on the vertical axis. To calculate BTUs per hour, multiply watts by
3.4123.
Figure 8. ST3146854SS (3 Gbit) DC current and power vs. input/output operations per second
ST3146854SS in 1.5 Gbit operation
Typical power dissipation under idle conditions in 1.5 Gbit operation is 14.64 watts (49.96 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 corresp5
volt current, +12 volt current, and total watts on the vertical axis. To calculate BTUs per hour, multiply watts by
3.4123.
Figure 9. ST3146854SS (1.5 Gbit) DC current and power vs. input/output operations per second
ST3146854SS DC CURRENT/POWER vs THROUGHPUT (3 Gbit)
Random 8 Block Reads
0.400
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0.800
1.000
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1.800
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I/Os per Second
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ST3146854SS DC CURRENT/POWER vs THROUGHPUT (1.5 Gbit)
Random 8 Block Reads
0.400
0.600
0.800
1.000
1.200
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1.600
1.800
0.0 50.0 100.0 150.0 200.0 250.0 300.0 350.0 400.0
I/Os per Second
Amperes
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5Vo lt A
12 Vo lt A
Watts