Performance Characteristics; Internal Drive Characteristics; Seek Performance Characteristics; Access Time - Seagate ST118273FC Product Manual

Barracuda 18FC Product Manual, Rev. B
4.0

Performance characteristics

This section provides detailed information concerning performance-related characteristics and features of
ST118273FC drives.
4.1

Internal drive characteristics

Drive capacity
Read/write data heads
Bytes per track
Bytes per surface
Cylinders/tracks per surface
Tracks per inch
Internal data rate
Disc rotation speed
Avg rotational latency
4.2

Seek performance characteristics

See section 9.5, "FC-AL physical interface" on page 46 and the Fibre Channel Interface Manual (part number
77767496) for additional timing details.
4.2.1

Access time

Average Typical
Maximum
Single track Typical
Maximum
Full stroke Typical
Maximum
1. Execution time measured from receipt of the FCP command to the FCP 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.
Access to data = controller overhead + average seek time + latency time.
5. Maximum times are specified over the worst case conditions of temperature, voltage margins, and drive orientation.
When comparing specified access times, care should be taken to distinguish between typical access times and maxi-
mum access times. The best comparison is obtained by system benchmark tests conducted under identical conditions.
Maximum times do not include error recovery.
Format command execution time for ≥ 512-byte sectors
4.2.2
Maximum (with verify)
Maximum (without verify)
ST118273FC
23.14 .........................Gbytes (unformatted)
18.21 .........................Gbytes (formatted with 512-byte logical blocks)
20
155,000 .........................Bytes (average, unformatted)
1,165 .........................Mbytes (unformatted)
7,501 .........................Tracks (user accessible)
8,250 .........................TPI
120-190 .........................Mbits/sec (variable with zone)
7,200 .........................rpm (± 0.5%)
4.17 .........................msec
Including controller overhead
Read
3 4
,
7.9
5
9.3
3,4
1.1
4
1.3
3,4
16
4
18.5
ST118273FC
80 minutes
40 minutes
1 2
,
(msec)
Write
8.7
9.6
1.4
1.6
18
20
9