Reliability Specifications; Error Rates; Recoverable Errors; Unrecoverable Errors - Seagate Cheetah 15K Product Manual

6.0

Reliability specifications

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.
Seek error rate:
Read Error Rates
Recovered Data
Unrecovered Data
Miscorrected Data
Interface error rate:
MTBF
AFR
Preventive maintenance:
6.1

Error rates

The error rates stated in this manual assume the following:
• The drive is operated per this specification using DC power as defined in this manual (see Section 7.2).
• 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.
• Error rate specified with automatic retries and data correction with ECC enabled and all flaws reallocated
6.1.1

Recoverable Errors

Recoverable errors are those detected and corrected by the drive, and do not require user intervention.
Recoverable Data errors use retries and correction. Application of ECC on-the-fly correction alone is not con-
sidered a Recovered Data error.
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.
6.1.2

Unrecoverable Errors

Unrecoverable Data Errors (Sense Key = 03h) are specified at less than 1 sector in error per 10
ferred. Unrecoverable Data Errors resulting from the same cause are treated as 1 error for that block.
Cheetah 15K.7 SAS Product Manual, Rev. C
Less than 10 errors in 10
Less than 10 errors in 10
16
Less than 1 sector in 10
21
Less than 1 sector in 10
12
Less than 1 error in 10
1,600,000 hours
0.55%
None required
8
seeks
12
bits transferred (OEM default settings)
bits transferred
bits transferred
bits transferred
16
bits trans-
13