ST936751SS in 3 Gbit operation

Typical power dissipation under idle conditions in 3Gb operation is 5.62 watts (19.18 BTUs per hour).

To obtain operating power for typical random read operations, refer to the following I/O rate curve (see Figure 3). 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.

CURRENT/POWER vs THROUGHPUT (SAS - 3.0GB)

Random 8 Block Reads

 

1.400

 

 

 

 

 

 

 

 

14.00

5Vo lt A

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

12 Vo lt A

 

1.200

 

 

 

 

 

 

 

 

12.00

Watts

 

 

 

 

 

 

 

 

 

 

 

 

1.000

 

 

 

 

 

 

 

 

10.00

Power (watts)

Amperes

0.800

 

 

 

 

 

 

 

 

8.00

0.600

 

 

 

 

 

 

 

 

6.00

 

 

 

 

 

 

 

 

 

 

 

0.400

 

 

 

 

 

 

 

 

4.00

 

 

0.200

 

 

 

 

 

 

 

 

2.00

 

 

0.000

 

 

 

 

 

 

 

 

0.00

 

 

0.0

50.0

100.0

150.0

200.0

250.0

300.0

350.0

400.0

450.0

 

I/Os per Second

Figure 5. ST936751SS (3 Gbit) DC current and power vs. input/output operations per second

ST936751SS in 1.5 Gbit operation

Typical power dissipation under idle conditions in 1.5 Gbit operation is 5.77 watts (19.69 BTUs per hour).

To obtain operating power for typical random read operations, refer to the following I/O rate curve (see Figure 3). 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.

CURRENT/POWER vs THROUGHPUT (SAS - 1.5GB)

Random 8 Block Reads

 

1.400

 

 

 

 

 

 

 

 

14.00

5Volt A

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

12 Volt A

 

1.200

 

 

 

 

 

 

 

 

12.00

Watts

 

 

 

 

 

 

 

 

 

 

 

 

1.000

 

 

 

 

 

 

 

 

10.00

Power (watts)

Amperes

0.800

 

 

 

 

 

 

 

 

8.00

0.600

 

 

 

 

 

 

 

 

6.00

 

 

 

 

 

 

 

 

 

 

 

0.400

 

 

 

 

 

 

 

 

4.00

 

 

0.200

 

 

 

 

 

 

 

 

2.00

 

 

0.000

 

 

 

 

 

 

 

 

0.00

 

 

0.0

50.0

100.0

150.0

200.0

250.0

300.0

350.0

400.0

450.0

 

I/Os per Second

Figure 6. ST936751SS (1.5 Gbit) DC current and power vs. input/output operations per second

28

Savvio 15K SAS Product Manual, Rev. B

Page 36
Image 36
Seagate ST973451SS manual ST936751SS in 3 Gbit operation, ST936751SS in 1.5 Gbit operation