Seagate ST9500621SS Constellation SAS Product Manual - Page 18

Performance characteristics

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5.0 Performance characteristics This section provides detailed information concerning performance-related characteristics and features of Constellation drives. 5.1 Internal drive characteristics Drive capacity Read/write data heads Bytes per track Bytes per surface Tracks per surface (total) Tracks per inch Peak bits per inch Areal density Internal data rate Disc rotation speed Avg rotational latency ST9500430SS, ST9500431SS & ST9500432SS 500 Gbytes (formatted, rounded off value) 6 890,823 Bytes (average, rounded off values) 83,370 Mbytes (unformatted, rounded off value) 123,148 Tracks (user accessible) 200,000 TPI (average) 1,410,000 283 BPI Gbit/in2 75 - 142 Mbytes/sec (variable with zone) 7,200 rpm 4.16 msec 5.2 Seek performance characteristics See Section 12.4.1, "SAS physical interface" on page 55 and the SAS Interface Manual (part number 100293071) for additional timing details. 5.2.1 Access time Average Single track Full stroke Typical3,4 Typical3,4 Typical3,4 Including controller overhead1, 2 (msec) Read Write 8.2 8.6 0.5 0.7 17.55 18.02 Not including controller overhead1, 2 (msec) Read Write 8.0 8.4 0.5 0.7 17.35 17.82 1. Execution time measured from receipt of the Command to the Response. 2. Assumes no errors and no sector has been relocated. 3. Typical access times are measured under nominal conditions of temperature, voltage, and horizontal orientation as measured on a representative sample of drives. 4. Access time = controller overhead + average seek time and applies to all data transfer commands. Access to data = access time + latency time. 10 Constellation SAS Product Manual, Rev. F

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10
Constellation SAS Product Manual, Rev. F
5.0
Performance characteristics
This section provides detailed information concerning performance-related characteristics and features of Con-
stellation drives.
5.1
Internal drive characteristics
ST9500430SS, ST9500431SS & ST9500432SS
Drive capacity
500
Gbytes (formatted, rounded off value)
Read/write data heads
6
Bytes per track
890,823
Bytes (average, rounded off values)
Bytes per surface
83,370
Mbytes (unformatted, rounded off value)
Tracks per surface (total)
123,148
Tracks (user accessible)
Tracks per inch
200,000
TPI (average)
Peak bits per inch
1,410,000
BPI
Areal density
283
Gbit/in
2
Internal data rate
75 - 142
Mbytes/sec (variable with zone)
Disc rotation speed
7,200
rpm
Avg rotational latency
4.16
msec
5.2
Seek performance characteristics
See Section 12.4.1, "SAS physical interface" on page 55 and the
SAS Interface Manual
(part number
100293071) for additional timing details.
5.2.1
Access time
Including controller overhead
2
1
1.
Execution time measured from receipt of the Command to the Response.
,
(msec)
Average
Typical
4
3
3.
Typical access times are measured under nominal conditions of temperature, voltage, and horizontal orientation as
measured on a representative sample of drives.
,
4.
Access time = controller overhead + average seek time and applies to all data transfer commands.
Access to data = access time + latency time.
8.2
8.6
8.0
8.4
Single track
Typical
3,4
0.5
0.7
0.5
0.7
Full stroke
Typical
3,4
17.55
18.02
17.35
17.82
2.
Assumes no errors and no sector has been relocated.
Not including controller overhead
1, 2
(msec)
Read
Write
Read
Write