Seagate ST9146802SS Performance characteristics, Internal drive characteristics, Access time

4.0Performance characteristics

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

4.1Internal drive characteristics

	ST9146802SS	ST973402SS
Drive capacity	146.8	73.4	Gbytes (formatted, rounded off value)
Read/write data heads	4	2
Bytes per track	489,984	489,984	Bytes (average, rounded off values)
Bytes per surface	36,704	36,704	Mbytes (unformatted, rounded off value)
Tracks per surface (total)	75,373	75,373	Tracks (user accessible)
Tracks per inch	150,000	150,000	TPI (average)
Peak bits per inch	925,000	925,000	BPI
Areal density	135	135	Gbit/in2
Internal data rate	660-1054	660-1054	Mbits/sec (variable with zone)
Disc rotation speed	10k	10k	rpm
Avg rotational latency	3.0	3.0	msec

4.2Seek performance characteristics

See Section 9.4.1, "SAS physical interface" on page 56 and the SAS Interface Manual (part number 100293071) for additional timing details.

4.2.1Access time

		Including controller overhead1, 2		Not including controller overhead1,2
		(msec)		(msec)
		Read	Write	Read	Write
Average	Typical3,4	4.0	4.6	3.8	4.4
Single track	Typical3,4	0.4	0.6	0.2	0.4
Full stroke	Typical3,4	8.17	8.76	7.97	8.56

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.

Data sheet data except full stroke which was Gen 2.0 data.

Savvio 10K.2 SAS Product Manual, Rev. B 11