Product manual

26 Cheetah 15K.3 FC Product Manual, Rev. D
6.3 Power dissipation
ST373453FC
Typical power dissipation under idle conditions in 2Gb operation is 12.7 watts (43.3 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 8. ST373453FC DC current and power vs. input/output operations per second
ST336753FC
Typical power dissipation under idle conditions in 2Gb operation is 11.0 watts (37.5 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. ST336753FC DC current and power vs. input/output operations per second
ST373453FC DC CURRENT/POWER vs THROUGHPUT (1Gb)
Random 8 Block Reads
0.400
0.600
0.800
1.000
1.200
1.400
1.600
1.800
0.0 50.0 100.0 150.0 200.0 250.0 300.0 350.0
I/Os per Second
Amperes
4.00
6.00
8.00
10 . 0 0
12 . 0 0
14 . 0 0
16 . 0 0
18 . 0 0
Power (watts)
5Volt A
12 V o l t A
Watts
ST336753FC DC CURRENT/POWER vs THROUGHPUT (1Gb)
Random 8 Block Reads
0.400
0.600
0.800
1.000
1.200
1.400
1.600
1.800
0.0 50.0 100.0 150.0 200.0 250.0 300.0 350.0
I/Os per Second
Amperes
4.00
6.00
8.00
10 . 0 0
12 . 0 0
14 . 0 0
16 . 0 0
18 . 0 0
Power (watts)
5Vo lt A
12 V o l t A
Wat ts