Performance Characteristics; Internal Drive Characteristics; Seek Performance Characteristics; Access Time - Seagate Constellation ST9500622SS Product Manual

5.0

Performance characteristics

This section provides detailed information concerning performance-related characteristics and features of Con-
stellation.2 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
Disk rotation speed
Avg rotational latency
5.2

Seek performance characteristics

See Section 12.4.1, "SAS physical interface" on page 63 and the SAS Interface Manual (part number
100293071) for additional timing details.
5.2.1

Access time

Average Typical
Single track Typical
Full stroke Typical
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.
Constellation.2 SAS Product Manual, Rev. H
ST91000640SS ST9500620SS
ST91000641SS ST9500621SS
ST91000642SS ST9500622SS
1000 500
8 4
732,998 732,998
125,069 125,069
165,800 165,800
270,000 270,000
1,544,000 1,544,000
417 417
84 - 163 84 - 163
7200 7200
4.16 4.16
Including controller overhead
(ms)
Read
3 4
7.7
,
0.23
3,4
3,4 17.26
Gbytes (formatted, rounded off value)
Bytes (average, rounded off values)
MB (unformatted, rounded off value)
Tracks (user accessible)
TPI (average)
BPI
2
Gb/in
MB/s (variable with zone)
rpm
ms
1 2
,
Not including controller overhead
(ms)
Write Read
8.7 7.5
0.44 0.23
18.28 17.06
1, 2
Write
8.5
0.44
18.08
11