Seagate Cheetah 18XL, Product Manual

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Cheetah 18XL Product Manual, Rev. A 25
6.3 Power dissipation
ST318404
For drives using single-ended interface circuits, typical power dissipation under idle conditions is 8.5 watts
(29.0 BTUs per hour).
For drives using low voltage differential interface circuits, typical power dissipation under idle conditions is 8.5
watts (29.0 BTUs per hour).
To obtain operating power for typical random read operations, refer to the following two I/O rate curves (see
Figures 7 and 8). Locate the typical I/O rate for a drive in your system on the horizontal axis and read the cor-
resp5 volt current, +12 volt current, and total watts on the vertical axis. To calculate BTUs per hour,
multiply watts by 3.4123.
Figure 7. ST318404 DC current and power vs. input/output operations per second (SE)
Figure 8. ST318404 DC current and power vs. input/output operations per second (LVD)
0.0
0 50 100
I/Os per Second
Amperes
150
0.2
0.4
0.6
0.8
1.0
1.2
5V A
12V A
0.0
0 50 100
I/Os per Second
Amperes
150
0.2
0.4
0.6
0.8
1.0
1.2
5V A
12V A