Seagate ST3450802SS ユーザーズマニュアル

12

Cheetah NS 10K.2 SAS Product Manual, Rev. C

The following reliability specifications assume correct host and drive operational interface, including all inter-
face timings, power supply voltages, environmental requirements and drive mounting constraints. 

The error rates stated in this manual assume the following: 

• The drive is operated in accordance with the manual using DC power as defined in Section 6.2.
• Errors caused by host system failures are excluded from error rate computations.
• Assume random data.
• Default OEM error recovery settings are applied. This includes AWRE, ARRE, full read retries, full write 

retries and full retry time.

Recoverable errors are those detected and corrected by the drive, and do not require user intervention.

Recoverable Data errors will use correction, although ECC on-the-fly is not considered for purposes of recov-
ered error specifications.

Recovered Data error rate is determined using read bits transferred for recoverable errors occurring during a 
read, and using write bits transferred for recoverable errors occurring during a write.

Unrecoverable Data Errors (Sense Key = 03h) are specified at less than 1 sector in error per 10

16

 bits trans-

ferred. Unrecoverable Data Errors resulting from the same cause are treated as 1 error for that block.

A seek error is defined as a failure of the drive to position the heads to the addressed track. After detecting an 
initial seek error, the drive automatically performs an error recovery process. If the error recovery process fails, 

Seek error rate:

Less than 10 errors in 10

8 

seeks

Read Error Rates

1

1.

Error rate specified with automatic retries and data correction with ECC enabled and all flaws reallocated.

Recovered Data

Less than 10 sector in 10

12

 bits transferred (OEM default settings)

Unrecovered Data

Less than 1 sector in 10

16

 bits transferred

Miscorrected Data

Less than 1 sector in 10

21

 bits transferred

Interface error rate:

Less than 1 error in 10

12

 bits transferred 

MTBF

1,600,000 hours

Annualized Failure Rate (AFR)

0.55%

Preventive maintenance:

None required