Seagate ST9900705SS Computer Drive User Manual


 
Savvio 10K.5 SAS Product Manual, Rev. D 9
5.0 Performance characteristics
This section provides detailed information concerning performance-related characteristics and features of Sav-
vio drives.
5.1 Internal drive characteristics
ST9900805SS ST9600205SS ST9450405SS ST9300605SS
ST9900705SS ST9600105SS ST9450305SS ST9300505SS
ST9900605SS ST9600005SS ST9450205SS ST9300405SS
Drive capacity 900 600 450 300 GB
(formatted, rounded off value)
Read/write data heads 6 4 3 2
Bytes per track 821.4 821.4 821.4 821.4 KBytes
(avg, rounded off values)
Bytes per surface 151,800 151,800 151,800 151,800 MB (unformatted, rounded off value)
Tracks per surface (total) 184,799 184,799 184,799 184,799 Tracks
(user accessible)
Tracks per inch 300 300 300 300 KTPI (average)
Peak bits per inch 1686 1686 1686 1686 kBPI
Areal density 506 506 506 506 Gb/in
2
Disc rotation speed 10K 10K 10K 10K rpm
Avg rotational latency 3.0 3.0 3.0 3.0 ms
5.2 Seek performance characteristics
See Section 12.4.1, "SAS physical interface" on page 67 and the SAS Interface Manual (part number
100293071) for additional timing details.
5.2.1 Access time
Including controller overhead
2
(ms)
1
1. Execution time measured from receipt of the Command to the Response.
,
Average
900GB models
Typical
3,4
3.9 4.3 3.7 4.1
Single track 0.4 0.6 0.2 0.4
Full stroke 7.9 8.3 7.7 8.1
Average
600, 450, 300GB
models
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.
3.6 4.0 3.4 3.8
Single track 0.4 0.6 0.2 0.4
Full stroke 7.3 7.6 7.1 7.4
2. Assumes no errors and no sector has been relocated.
Not including controller overhead
1,2
(ms)
Read Write Read Write