10 Constellation ES Series SAS Product Manual, Rev. F

5.0 Performance characteristics

This section provides detailed information concerning performance-related characteristics and features of Con-

stellation ES drives.

5.1 Internal drive characteristics

ST32000444SS ST31000424SS ST3500414SS
ST32000445SS ST31000425SS ST3500415SS
ST32000446SS ST31000426SS ST3500416SS
Drive capacity 2000 1000 500 GB (formatted, rounded off value)
Read/write data heads 8 4 2
Bytes per track 1,012,6 08 1,012,608 1,012,608 Bytes (average, rounded off values)
Bytes per surface 250 ,000 250,000 250,000 MB (unformatted, rounded off value)
Tracks per surface (total) 248,600 248,600 248,600 Tracks (user accessible)
Tracks per inch 237,000 237,000 237,000 TPI (average)
Peak bits per inch 1,515,000 1,515,000 1,515,000 BPI
Areal density 347 347 347 Gb/in2
Internal data rate 95 - 212 95 - 212 95 - 212 MB/s (variable with zone)
Disc rotation speed 7200 7200 7200 rpm
Avg rotational latency 4.16 4.16 4.16 ms

5.2 Seek performance characteristics

See Section 12.4.1, "SAS physical interface" on page 64 and the SAS Interface Manual (part number

100293071) for additional timing details.

5.2.1 Access time

Not including controller overhead 2 (ms)
1
1. Execution time measured from receipt of the Command to the Response.
,
Average Typical 43
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.
8.3 9.3 8.5 9.5
Single track Typical3,4 0.5 0.8 0.7 1.0
Full stroke Typical3,4 18 19 18.2 19.2
2. Assumes no errors and no sector has been relocated.
Including controller overhead1, 2 (ms)
Read Write Read Write