IBM IC25N040ATCS04 Hard Drive Specifications - Page 27

Performance characteristics, 4.1 Command overhead - travelstar model 0

Get IBM IC25N040ATCS04 - Travelstar 40 GB Hard Drive PDF manuals and user guides View all IBM IC25N040ATCS04 manuals
Add to My Manuals
Save this manual to your list of manuals

Page 27 highlights

4.4 Performance characteristics Drive performance is characterized by the following parameters: ! Command Overhead ! Mechanical Positioning # Seek Time # Latency ! Data Transfer Speed ! Buffering Operation (Look ahead/Write Cache) Note: All the above parameters contribute to drive performance. There are other parameters which contribute to the performance of the actual system. This specification defines the essential characteristics of the drive. 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. The detailed descriptions are found in section 5.0. Function Average Random Seek Time - Read (ms) Average Random Seek Time - Write (ms) Rotational Speed (RPM) Power-on-to-ready (sec) Command overhead (ms) Disk-buffer data transfer (Mb/s) Buffer-host data transfer (MB/s) 60-GB 12 14 5400 5.0 1.0 146-261 100 All other models 12 14 4200 3.0 1.0 130-245 125-241 100 Figure 8. Performance characteristics 4.4.1 Command overhead Command overhead time is defined as the interval from the time that a drive receives a command to the time that the actuator starts its motion. Travelstar 60GH & 40GN hard disk drive specifications 14

  • 1
  • 2
  • 3
  • 4
  • 5
  • 6
  • 7
  • 8
  • 9
  • 10
  • 11
  • 12
  • 13
  • 14
  • 15
  • 16
  • 17
  • 18
  • 19
  • 20
  • 21
  • 22
  • 23
  • 24
  • 25
  • 26
  • 27
  • 28
  • 29
  • 30
  • 31
  • 32
  • 33
  • 34
  • 35
  • 36
  • 37
  • 38
  • 39
  • 40
  • 41
  • 42
  • 43
  • 44
  • 45
  • 46
  • 47
  • 48
  • 49
  • 50
  • 51
  • 52
  • 53
  • 54
  • 55
  • 56
  • 57
  • 58
  • 59
  • 60
  • 61
  • 62
  • 63
  • 64
  • 65
  • 66
  • 67
  • 68
  • 69
  • 70
  • 71
  • 72
  • 73
  • 74
  • 75
  • 76
  • 77
  • 78
  • 79
  • 80
  • 81
  • 82
  • 83
  • 84
  • 85
  • 86
  • 87
  • 88
  • 89
  • 90
  • 91
  • 92
  • 93
  • 94
  • 95
  • 96
  • 97
  • 98
  • 99
  • 100
  • 101
  • 102
  • 103
  • 104
  • 105
  • 106
  • 107
  • 108
  • 109
  • 110
  • 111
  • 112
  • 113
  • 114
  • 115
  • 116
  • 117
  • 118
  • 119
  • 120
  • 121
  • 122
  • 123
  • 124
  • 125
  • 126
  • 127
  • 128
  • 129
  • 130
  • 131
  • 132
  • 133
  • 134
  • 135
  • 136
  • 137
  • 138
  • 139
  • 140
  • 141
  • 142
  • 143
  • 144
  • 145
  • 146
  • 147
  • 148
  • 149
  • 150
  • 151
  • 152
  • 153
  • 154
  • 155
  • 156
  • 157
  • 158
  • 159
  • 160
  • 161
  • 162
  • 163
  • 164
  • 165
  • 166
  • 167
  • 168
  • 169
  • 170
  • 171
  • 172
  • 173
  • 174
  • 175
  • 176
  • 177
  • 178
  • 179
  • 180
  • 181
  • 182
  • 183
  • 184
  • 185
  • 186
  • 187
  • 188
  • 189
  • 190
  • 191
  • 192
  • 193
  • 194
  • 195
  • 196
  • 197
  • 198
  • 199
  • 200
  • 201
  • 202
  • 203
  • 204
  • 205
  • 206
  • 207
  • 208
  • 209
  • 210
  • 211
  • 212
  • 213
  • 214
  • 215
  • 216
  • 217
4.4 Performance characteristics
Drive performance is characterized by the following parameters:
!
Command Overhead
!
Mechanical Positioning
#
Seek Time
#
Latency
!
Data Transfer Speed
!
Buffering Operation (Look ahead/Write Cache)
Note: All the above parameters contribute to drive performance. There are other parameters which contri-
bute to the performance of the actual system. This specification defines the essential characteristics of the
drive. 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. The detailed descriptions are found in
section 5.0.
100
100
Buffer-host data transfer (MB/s)
130-245
125-241
146-261
Disk-buffer data transfer (Mb/s)
1.0
1.0
Command overhead (ms)
3.0
5.0
Power-on-to-ready (sec)
4200
5400
Rotational Speed (RPM)
14
14
Average Random Seek Time - Write (ms)
12
12
Average Random Seek Time - Read (ms)
All other models
60-GB
Function
Figure 8. Performance characteristics
4.4.1 Command overhead
Command overhead time is defined as the interval from the time that a drive receives a command to the
time that the actuator starts its motion.
Travelstar 60GH & 40GN hard disk drive specifications
14