Hitachi HUS154530VLF400 User Manual
Hitachi Ultrastar 15K450 (FC-AL) Hard Disk Drive Specification
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4.5.2 Drive ready time
Table 9: Drive ready time
4.5.3 Spindle stop time
Table 10: Spindle stop time
The period from power off to the complete stop of the rotating spindle is categorized as 'operating'. The Operating shock crite-
ria apply during this period. Refer to section 12.3, “Operating shock” on page 41.
ria apply during this period. Refer to section 12.3, “Operating shock” on page 41.
4.5.4 Data transfer speed
Table 11: Data transfer speed (sector size 512 Byte case)
Notes:
•
Instantaneous disk-buffer transfer rate is derived by: (Number of sectors on a track) x 512 x (revolutions/sec)
•
For this table, '1 MB / Sec' should be interpreted as 1,000,000 bytes per Second.
•
The number of sectors per track will vary by zone because of the linear density recording.
•
Sustained disk-buffer transfer rate is the average rate measured while transferring multiple cylinders of data. It dif-
fers from the instantaneous transfer rate because of the time required to change tracks (Cylinder skew and Head
skew). In addition, time is added for the occasional missed transfer.
skew). In addition, time is added for the occasional missed transfer.
4.5.5 Buffering operation (read ahead/write cache)
This hard disk drive has a buffer for read ahead (see Segmented Caching, page 331).
Model
Typical (sec)
Maximum (sec)
450 GB Model
21.0
29.9
300 GB Model
21.0
29.9
Model
Typical (sec)
Maximum (sec)
450 GB Model
11.0
20
300 GB Model
11.0
20
Description
Disk-buffer transfer
Typical (MB / Sec)
Zone
Model
Read
Write
Instantaneous
0
450 GB
179.7
179.7
0
300 GB
152.1
152.1
Measured typical values for sustained disk-
buffer tranfer rate
buffer tranfer rate
0
450 GB
160.0
155.8
0
300 GB
135.0
131.5
Instantaneous
22
450 GB
112.3
112.3
17
300 GB
110.6
110.6
Measured typical values for sustained disk-
buffer tranfer rate
buffer tranfer rate
22
450 GB
99.9
97.3
17
300 GB
98.2
95.6