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6.5 Reliability
6.5.1 Annualized failure rate
This product has a 0.35% AFR specification rating based on typical workload and temperatures.
The AFR specification is based on a sample population and is estimated by statistical measurements and
acceleration algorithms under typical operating conditions at 40° C device reported temperature.
Derating of AFR will occur above these parameters, up to 550TB/YR workload and 60° C (device reported temp).
AFR ratings do not predict an individual drive’s reliability and do not constitute a warranty.
6.5.2
Data integrity
OptiNAND™’s Enhance Data Safety feature allows up to 128MiB of user data protection in event of Emergency
Power Off event. Data is power-loss safe in both Write Cache Enabled and Write Cache Disabled modes.
No customer data is lost during power loss. If write cache option is active, user data will be written to iNAND upon
successful completion of a FLUSH CACHE (E7h) or FLUSH CACHE EXT (EAh) command. This feature can be
disabled to cause FLUSH CACHE commands to flush data to media instead of iNAND if desired.
6.5.3
Cable noise interference
To avoid any degradation of performance throughput or error rate when the interface cable is routed on top or
comes in contact with the HDA assembly, the drive must be grounded electrically to the system frame by four
screws. The common mode noise or voltage level difference between the system frame and power cable ground or
AT interface cable ground should be in the allowable level specified in the power requirement section.
6.5.4
Load/Unload
The product supports a minimum of 600,000 normal load/unloads in a 40° C environment.
Load/unload is invoked by transition of the HDD's power mode. (Chapter 4.5.3 Operating modes)
Idle (Idle_A) <-> unload idle (Idle_B)
Idle (Idle_A) <-> Low rpm idle (Idle_C)
6.5.5
Start/stop cycles
The drive withstands a minimum of 50,000 start/stop cycles in a 40° C environment and a minimum of 10,000
start/stop cycles in extreme temperature or humidity within the operating range.
6.5.6
Preventive maintenance
None 6.5.7 Data reliability
Probability of not recovering data is 1 in 1015 bits read.
LDPC on the fly/ offline data correction
4608-bit LDPC
This implementation recovers maximum 2500 bits single burst error by on-the-fly correction and maximum
3500 bits single burst error by offline correction. 6.5.8 Required Power-Off Sequence
The required sequence for removing power from the drive is as follows:
Step 1: Issue a STOP UNIT Command
Standby
Standby immediate
Sleep
Note: Do not use the Flush Cache command for the power off sequence because this command does not invoke
Unload
Step 2: Wait until the Command Complete status is returned. However, the time out value needs to be 60
seconds considering error recovery time.
Step 3: Terminate power to HDD.
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Hard Disk Drive Specification