Seagate ST400FM0012 ユーザーズマニュアル

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The following reliability specifications assume correct host and drive operational interface, including all interface 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 this manual using DC power as defined in paragraph 6.3, "DC power requirements."
• 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.

An unrecoverable data error is defined as a failure of the drive to recover data from the media. These errors occur due to read or write 
problems. Unrecoverable data errors are only detected during read operations, but not caused by the read. If an unrecoverable data error 
is detected, a MEDIUM ERROR (03h) in the Sense Key will be reported. Multiple unrecoverable data errors resulting from the same cause 
are treated as 1 error.

An interface error is defined as a failure of the receiver on a port to recover the data as transmitted by the device port connected to the 
receiver. The error may be detected as a running disparity error, illegal code, loss of word sync, or CRC error.

Read Error Rates  

1

1. Error rate specified with automatic retries and data correction with ECC enabled and all flaws reallocated.
2. As NAND Flash devices age with use, the capability of the media to retain a programmed value begins to deteriorate. 

This deterioration is affected by the number of times a particular memory cell is programmed and subsequently erased. 
When a device is new, it has a powered off data retention capability of up to several years. With use the retention ca-
pability of the device is reduced. Temperature also has an effect on how long a Flash component can retain its pro-
grammed value with power removed. At high temperature the retention capabilities of the device are reduced. Data 
retention is not an issue with power applied to the SSD. The SSD drive contains firmware and hardware features that 
can monitor and refresh memory cells when power is applied.

3. Endurance rating is the expected amount of host data that can be written by product when subjected to a specified work-

load at a specified operating and storage temperature. For the specific workload to achieve this level of endurance, 
please reference JEDEC Specification JESD218. TBW is defined as 1x10^12 Bytes.

Unrecovered Data

Less than 1 LBA in 10

16

 bits transferred

Miscorrected Data

Less than 1 LBA in 10

21

 bits transferred

Interface error rate:

Less than 1 error in 10

12

 bits transferred

Mean Time Between Failure (MTBF):

2,000,000 hours

Annualized Failure Rate (AFR):

0.44%

Preventive maintenance:

None required

Typical Data Retention with 
Power removed (at 40C)  

2

3 months

Method 1:  Full drive writes per day    10  

Method 2:  TBW (per JEDEC JESD218     800GB = 17,800 TB
                                                                    400GB =   8800 TB
                                                                    200GB =   4400 TB
                                                                    100GB =   2200 TB