10 Savvio 15K.2 SAS Product Manual, Rev. E

5.0 Performance characteristics

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

vio drives.

5.1 Internal drive characteristics

ST9146852SS ST973452SS
ST9146752SS ST973352SS
ST9146652SS ST973252SS
Drive capacity 146.8 73.4 Gbytes (formatted, rounded off value)
Read/write data heads 4 2
Tracks per surface (total) 60,436 60,436 Tracks (user accessible including spare tracks)
Tracks per inch 180,000 180,000 kTPI (average)
Peak bits per inch 1,317 1,317 kBPI
Areal density 237.1 237.1 Gbit/in 2
Internal data rate 1,936 - 1,409 1,936 - 1,409 Mbits/sec (variable with zone)
Disk rotation speed 15k 15k rpm
Avg rotational latency 2.0 2.0 msec

5.2 Seek performance characteristics

See Section 12.4.1, "SAS physical interface" on page 57 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 Comma nd to the Response.
,
(msec)
Average Typica l 43
3. Typical access times are measured under nominal conditions of temperature, voltage, and ho rizontal 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.
3.1 3.5 2.9 3.3
Single track Typi cal3,4 0.2 0.42 0.2 0.42
Full stroke Typi cal3,4 5.05 5.4 4.85 5.2
2. Assumes no errors and no sector has been relocated.
Not including controller overhead1, 2
(msec)
Read Write Read Write