Hitachi hard disk 0J11285 500 GB 2.5 " 8 MB 0J11285 Ficha De Dados
Códigos do produto
0J11285
Z5K500 OEM Specifications
18
4.4
Performance characteristics
Hard disk drive performance is characterized by the following parameters:
Command Overhead
Mechanical Positioning
Mechanical Positioning
Seek Time
Latency
Latency
Data Transfer Speed
Buffering Operation (Look ahead/Write Cache)
Buffering Operation (Look ahead/Write Cache)
Note: All the above parameters contribute to the hard disk drive performance. There are other parameters
which contribute to the performance of the actual system. This specification defines the essential
characteristics of the hard disk drives. This specification does not include the system throughput as this is
dependent upon the system and the application.
which contribute to the performance of the actual system. This specification defines the essential
characteristics of the hard disk drives. This specification does not include the system throughput as this is
dependent upon the system and the application.
The following table gives a typical value for each parameter.
Function
Average Random Seek Time – Read/Write (ms)
13
Rotational Speed (RPM)
5400
Power-on-to-ready (sec)
3.5
Disk-buffer data transfer (Mb/s) (max)
1004
Buffer-host data transfer (Gbit/s) (max)
3.0 / 6.0
Table 4 Performance characteristics
4.4.1
Mechanical positioning
4.4.1.1
Average seek time (including settling)
Command Type
Typical (ms)
Max. (ms)
Read/Write 13
18
Table 5 Mechanical positioning performance
Typical and Max. are defined as followings:
Typical
Average of the hard disk drive population tested at nominal environmental and voltage
conditions.
conditions.
Max.
Maximum value measured on any hard disk drive over the full range of the environmental and
voltage conditions.
(See section 6.1, "Environment" and section 6.2, "DC power requirements" )
voltage conditions.
(See section 6.1, "Environment" and section 6.2, "DC power requirements" )
The seek time is measured from a start of motion of an actuator to the start of a reliable read or write
operation. A reliable read or write operation implies that error correction/recovery is not employed to
correct arrival problems. The Average Seek Time is measured as the weighted average of all possible
seek combinations.
operation. A reliable read or write operation implies that error correction/recovery is not employed to
correct arrival problems. The Average Seek Time is measured as the weighted average of all possible
seek combinations.
max.
(max. + 1 – n)(Tn
in
+ Tn
out
)
n=1
Weighted Average = ––––––––––––––––––––––––––––
(max.
(max.
+
1)(max)
Where: max.
= maximum seek length
n = seek length (1-to-max.)
Tn
Tn
in
= inward measured seek time for an n-track seek
Tn
out
= outward measured seek time for an n-track seek