Hitachi 7K250 Specifications - Page 34

Operating modes

Page 34 highlights

B = Average seek time (sec) C = Latency D = Average sustained disk-buffer transfer rate (byte/s) E = Buffer-host transfer rate (byte/s) 4.4.6 Operating modes 4.4.6.1 Description of operating modes Table 15: Description of operating modes Operating mode Spin-up Seek Write Read Unload Idle Idle Standby Sleep Description Start up time period from spindle stop or power down. Seek operation mode Write operation mode Read operation mode Spindle rotation at 7200 RPM with heads unloaded. Spindle motor and servo system are working normally. Commands can be received and processed immediately. Actuator is unloaded and spindle motor is stopped. Commands can be received immediately. TActuator is unloaded and spindle motor is stopped. Only soft reset or hard reset can change the mode to standby. Note: Upon power down or spindle stop a head locking mechanism will secure the heads in the OD parking position. 4.4.6.2 Mode transition time Table 16: Mode transition time From Standby Idle Standby Sleep Unload idle Idle To Idle Standby Sleep Standby Idle Unload idle RPM 0 ---> 7200 (3disks) 7200 ---> 0 0 0 7200 7200 Transition time (sec) Typical Maximum 9 31 Immediately Immediately Immediately Immediately Immediately 0.7 0.7 Immediately "Immediately" means within 1ms. Note: The command is processed immediately but there will be an actual spin down time reflecting the seconds passed until the spindle motor stops. Deskstar 7K250 Hard Disk Drive Specification 20

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Deskstar 7K250 Hard Disk Drive Specification
20
B = Average seek time (sec)
C = Latency
D = Average sustained disk-buffer transfer rate (byte/s)
E = Buffer-host transfer rate (byte/s)
4.4.6
Operating modes
4.4.6.1
Description of operating modes
Note:
Upon power down or spindle stop a head locking mechanism will secure the heads in the OD parking posi-
tion.
4.4.6.2
Mode transition time
"Immediately" means within 1ms.
Note:
The command is processed immediately but there will be an actual spin down time reflecting the seconds
passed until the spindle motor stops.
Table 15: Description of operating modes
Operating mode
Description
Spin-up
Start up time period from spindle stop or power down.
Seek
Seek operation mode
Write
Write operation mode
Read
Read operation mode
Unload Idle
Spindle rotation at 7200 RPM with heads unloaded.
Idle
Spindle motor and servo system are working normally. Commands can be received and pro-
cessed immediately.
Standby
Actuator is unloaded and spindle motor is stopped. Commands can be received immediately.
Sleep
TActuator is unloaded and spindle motor is stopped. Only soft reset or hard reset can change
the mode to standby.
Table 16: Mode transition time
From
To
RPM
Transition time (sec)
Typical
Maximum
Standby
Idle
0 ---> 7200 (3disks)
9
31
Idle
Standby
7200 ---> 0
Immediately
Immediately
Standby
Sleep
0
Immediately
Immediately
Sleep
Standby
0
Immediately
Immediately
Unload idle
Idle
7200
0.7
Idle
Unload idle
7200
0.7