Seagate ST9146853SS Savvio 15K.1 SAS Product Manual - Page 18

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Savvio 15K SAS Product Manual, Rev. C

4.2.2

Format command execution time

Execution time measured from receipt of the last byte of the Command Descriptor Block (CDB) to the request

for a Status Byte Transfer to the Initiator (excluding connect/disconnect).

4.2.3

General performance characteristics

4.3

Start/stop time

The drive accepts the commands listed in the SAS Interface Manual less than 3 seconds after DC power has

been applied.

If the drive receives a NOTIFY (ENABLE SPINUP) primitive through either port and has not received a START

STOP UNIT command with the START bit equal to 0, the drive becomes ready for normal operations within 20

seconds (excluding the error recovery procedure).

If the drive receives a START STOP UNIT command with the START bit equal to 0 before receiving a NOTIFY

(ENABLE SPINUP) primitive, the drive waits for a START STOP UNIT command with the START bit equal to 1.

After receiving a START STOP UNIT command with the START bit equal to 1, the drive waits for a NOTIFY

(ENABLE SPINUP) primitive. After receiving a NOTIFY (ENABLE SPINUP) primitive through either port, the

drive becomes ready for normal operations within 20 seconds (excluding the error recovery procedure).

If the drive receives a START STOP UNIT command with the START bit and IMMED bit equal to 1 and does

not receive a NOTIFY (ENABLE SPINUP) primitive within 5 seconds, the drive fails the START STOP UNIT

command.

The START STOP UNIT command may be used to command the drive to stop the spindle. Stop time is 30 sec-

onds (maximum) from removal of DC power. There is no power control switch on the drive.

4.4

Prefetch/multi-segmented cache control

The drive provides a prefetch (read look-ahead) and multi-segmented cache control algorithms that in many

cases can enhance system performance. Cache refers to the drive buffer storage space when it is used in

cache operations. To select this feature, the host sends the Mode Select command with the proper values in

the applicable bytes in page 08h. Prefetch and cache operations are independent features from the standpoint

that each is enabled and disabled independently using the Mode Select command; however, in actual opera-

tion, the prefetch feature overlaps cache operation somewhat as described in sections 4.5.1 and 4.5.2.

ST973451SS

ST936751SS

Maximum (with verify)

52 minutes

26 minutes

Maximum (without verify)

35 minutes

18 minutes

Sustained trasfer rate

79 to 112 Mbytes/sec

SAS Interface maximum instantaneous transfer rate

300 Mbytes/sec* per port

(dual port = 600 Mbytes/sec*)

Logical block sizes

512 (default), 520, 524 and 528

Read/write consecutive sectors on a track

Yes

Flaw reallocation performance impact (for flaws reallocated at format time using the

spare sectors per sparing zone reallocation scheme.)

Negligible

Average rotational latency

2.0 msec

*Assumes no errors and no relocated logical blocks. Rate measured from the start of the first logical block transfer to or

from the host.

Section	Page
1.0 Scope	7
2.0 Applicable standards and reference documentation	9
2.1 Standards	9
2.1.1 Electromagnetic compatibility	9
2.1.1.1 Electromagnetic susceptibility	9
2.1.2 Electromagnetic compliance	10
2.1.3 European Union Restriction of Hazardous Substances (RoHS)	11
2.2 Reference documents	11
3.0 General description	13
3.1 Standard features	14
3.2 Media description	14
3.3 Performance	14
3.4 Reliability	15
3.5 Formatted capacities	15
3.6 Programmable drive capacity	15
3.7 Factory-installed accessories	15
3.8 Options	16
4.0 Performance characteristics	17
4.1 Internal drive characteristics	17
4.2 Seek performance characteristics	17
4.2.1 Access time (Gen 2.0 LP data)	17
4.2.2 Format command execution time	18
4.2.3 General performance characteristics	18
4.3 Start/stop time	18
4.4 Prefetch/multi-segmented cache control	18
4.5 Cache operation	19
4.5.1 Caching write data	19
4.5.2 Prefetch operation	20
5.0 Reliability specifications	21
5.1 Error rates	21
5.1.1 Recoverable Errors	21
5.1.2 Unrecoverable Errors	21
5.1.3 Seek errors	22
5.1.4 Interface errors	22
5.2 Reliability and service	22
5.2.1 Annualized Failure Rate (AFR) and Mean Time Between Failure (MTBF)	22
5.2.2 Preventive maintenance	22
5.2.3 Hot plugging the drive	22
5.2.4 S.M.A.R.T.	23
5.2.5 Thermal monitor	24
5.2.6 Drive Self Test (DST)	24
5.2.6.1 DST failure definition	25
5.2.6.2 Implementation	25
5.2.6.2.1 State of the drive prior to testing	25
5.2.6.2.2 Invoking DST	25
5.2.6.2.3 Short and extended tests	25
5.2.6.2.4 Log page entries	26
5.2.6.2.5 Abort	26
5.2.7 Product warranty	26
6.0 Physical/electrical specifications	29
6.1 AC power requirements	29
6.2 DC power requirements	29
6.2.1 Conducted noise immunity	31
6.2.2 Power sequencing	31
6.2.3 Current profiles	31
6.3 Power dissipation	33
6.4 Environmental limits	35
6.4.1 Temperature	35
6.4.2 Relative humidity	35
6.4.3 Effective altitude (sea level)	36
6.4.4 Shock and vibration	36
6.4.4.1 Shock	36
6.4.4.2 Vibration	38
6.4.5 Air cleanliness	38
6.4.6 Corrosive environment	38
6.4.7 Acoustics	39
6.4.8 Electromagnetic susceptibility	39
6.5 Mechanical specifications	40
7.0 Defect and error management	41
7.1 Drive internal defects/errors	41
7.2 Drive error recovery procedures	41
7.3 SAS system errors	42
7.4 Background Media Scan	43
7.5 Media Pre-Scan	43
7.6 Deferred Auto-Reallocation	43
7.7 Idle Read After Write	44
8.0 Installation	45
8.1 Drive orientation	45
8.2 Cooling	46
8.3 Drive mounting	47
8.4 Grounding	47
9.0 Interface requirements	49
9.1 SAS features	49
9.1.1 task management functions	49
9.1.2 Task management responses	49
9.2 Dual port support	50
9.3 SCSI commands supported	51
9.3.1 Inquiry data	55
9.3.2 Mode Sense data	55
9.4 Miscellaneous operating features and conditions	59
9.4.1 SAS physical interface	60
9.4.2 Physical characteristics	63
9.4.3 Connector requirements	63
9.4.4 Electrical description	63
9.4.5 Pin descriptions	63
9.4.6 SAS transmitters and receivers	64
9.4.7 Power	65
9.5 Signal characteristics	65
9.5.1 Ready LED Out	65
9.5.2 Differential signals	65
9.5.2.1 Eye masks	66
9.5.2.1.1 Eye masks overview	66
9.5.2.1.2 Receive eye mask	66
9.5.2.1.3 Jitter tolerance masks	67
9.5.2.2 Transmitter signal characteristics	68
9.5.2.3 Receiver signal characteristics	69
9.5.2.3.1 Jitter	70
9.5.2.3.2 Receiver jitter tolerance	70
9.5.2.3.3 Compliant jitter test pattern (CJTPAT)	70
9.5.2.3.4 Impedance specifications	71
9.5.2.4 Electrical TxRx connections	72
9.5.2.4.1 Transmitter characteristics	72
9.5.2.5 Receiver characteristics	75
10.0 Seagate Technology support services	77
Numerics	79
A	79
B	79
C	79
D	79
E	79
F	80
G	80
H	80
I	80
J	80
L	80
M	80
N	81
O	81
P	81
Q	81
R	81
S	81
T	82
U	82
V	82
W	82

Seagate ST9146853SS Savvio 15K.1 SAS Product Manual - Page 18

Start/stop time, Prefetch/multi-segmented cache control

Page 18 highlights