Technical information

HGST Ultrastar C15K600 Hard Disk Drive Specification
45
10
Reliability
10.1
Start/Stop Cycles
The drive is designed to withstand a minimum of 50,000 start/stop cycles at ambient environment.
The drive is designed to withstand a minimum of 10,000 start/stop cycles at the operating environment conditions
specified in Chapter 8.0, “Environment”.
10.2
Load/Unload Cycles
The drive is designed to withstand a minimum of 600,000 load/unload cycles at the operating environmental
conditions specified in Chapter 8.0, “Environment”.
10.3
Data Reliability
The probability of an uncorrectable data error on a population average is 10 in 1x10
17
bits read.
The channel design is changed from the prior generation of DASD devices to use an LDPC channel having similar
code rate to prior Reed Solomon error correction. The design of the LDPC channel includes usage of media defect
detection circuits for locating defects and performing erasure correction, replacing the offline erasure correction
capability of RS codes. Modulation coding properties for timing and gain recovery are equivalent to prior product
generation
LDPC implementation:
- Single LDPC codeword per sector with 576 bits of parity for 512n (4kB format LDPC overhead is 4608 which
is exactly 8*576)
- Media defect detection circuit using erasure flags to zero LLR values
- LDPC code designed to correct defects up to 425 bits for 512n
- LBA seeded 32 bit CRC on the sector, plus a 72 bit media ECC for miscorrect detection
10.4
Seek Errors
A non-recoverable seek/ID miscompare error is defined as a seek operation that cannot be recovered by the error
recovery procedure of the drive. The drive reports sense key 04 and sense code 02 for this error.
No drive has more than ten non-recoverable seek/ID miscompare error per 100 million seek operations (<10 in 1x
10
8
) when operated at the full range of voltage and environmental conditions.
10.5
Failure Prediction (S.M.A.R.T)
SMART Monitoring Parameters are checked to determine if the (Read/Write/Seek) error rates exceed the drive’s
threshold value when an error occurs and a minimum amount of operation has been completed. A check is also
performed for a minimum level of Spare Sector Availability.
The Head Load / Unload Count, Spin Up Time and Spin Up Retry Count parameters are checked prior to reporting a
“Ready” condition at Power On. Smart monitors Milliactuator calibration which occurs at power on and in error
recovery. SMART monitors unrecoverable corrupted critical segments of the Reserved Area. If SMART reports a
problem in the Reserved Area, all data should be recovered from the drive before a power cycle.