IBM DCAS-32160 - Ultrastar 2.1 GB Hard Drive, Технические характеристики

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3.4.6 Throughput
3.4.6.1 Simple Sequential Access
The above table gives the time required to read/write for a total of 8000x consecutive blocks (16,777,216
bytes) accessed by 128 read/write commands. Typical and Max values are given by 105% and 110% of T
respectively throughput following performance description.
Note: Assumes a host system responds instantaneously.
T = (A * 128) + B + C + 16,777,216/D + 512/E (READ)
T = (A * 128) + B + C + 16,777,216/D (WRITE)
where:
T = Calculated Time (sec)
A = Command Process Time (Pre/Post Command overhead)
B = Average Seek Time
C = Average Latency
D = Sustained Disk-Buffer Transfer Rate (Mbyte/sec)
E = Buffer-Host Transfer Rate (Mbyte/sec)
3.4.6.2 Random Access
The above table gives the time required to execute a total of 1000x read/write commands which access a
random LBA.
T = (A + B + C + 512/D + 512/E) * 4096 (READ)
T = (A + B + C + 512/D) * 4096 (WRITE)
where:
T = Calculated Time (sec)
A = Command Process Time (Pre/Post Command overhead)
B = Average Seek Time
C = Average Latency
D = Sustained Disk-Buffer Transfer Rate (Mbyte/sec)
E = Buffer-Host Transfer Rate (Mbyte/sec)
Figure 11. Simple Sequential Access Performance
Operation Typical Max
Sequential Read/Write Zone 0 2.26 [ sec]
Zone 7 3.56 [ sec]
Zone 0 2.37 [ sec]
Zone 7 3.73 [ sec]
Figure 12. Random Access Performance
Operation Typical Max
Random Read 64 [ sec] 67 [ sec]
Random Write 64 [ sec] 67 [ sec]
Drive Characteristics
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