5.0Performance characteristics

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

5.1Internal 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/in2

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

5.2Seek 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.

5.2.1Access time

 

 

Including controller overhead1, 2

Not including controller overhead1, 2

 

 

(msec)

 

(msec)

 

 

 

Read

Write

Read

Write

Average

Typical3,4

3.1

3.5

2.9

3.3

Single track

Typical3,4

0.2

0.42

0.2

0.42

Full stroke

Typical3,4

5.05

5.4

4.85

5.2

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.

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

Page 18
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Seagate ST973452SS manual Performance characteristics, Internal drive characteristics, Seek performance characteristics