Seagate ST3146854LC manual Performance characteristics, Internal drive characteristics, Seek time

4.0Performance characteristics

This section provides detailed information concerning performance-related characteristics and features of Cheetah 15K.6 drives.

4.1Internal drive characteristics

	ST3450856SS	ST3300656SS	ST3146356SS
	ST3450056SS	ST3300056SS	ST3146756SS
Drive capacity	450	300	146	Gbytes (formatted, rounded off value)*
Read/write data heads	8	6	3
Tracks per inch	150,000	150,000	150,000	TPI
Peak bits per inch	1,100	1,100	1,100	KBPI
Areal Density	165	165	165	Gbits/inch2
Internal data rate	1.95	1.95	1.95	Gbits/sec (max)
disk rotation speed	15k	15k	15k	RPM
Avg rotational latency	2.0	2.0	2.0	msec

*One Gbyte equals one billion bytes when referring to hard drive capacity. Accessible capacity may vary depending on operating environment and formatting.

4.2Seek time

See Section 9.4.1, "SAS physical interface" on page 62 and the SAS Interface Manual (part number 100293071) for additional timing details.

4.2.1Access time

Not Including controller overhead1, 2 (msec)

		Read	Write
Average	Typical	3.4	3.9
Single track	Typical	0.20	0.44
Full stroke	Typical	6.43	7.12

1.Typical access times are measured under nominal conditions of temperature, voltage, and horizontal orientation as measured on a representative sample of drives.

2.Access to data = access time + latency time.

Cheetah 15K.6 SAS Product Manual, Rev. B 11