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Table 5-6: Baseline S.M.A.R.T. Attribute Details
Rate
Raw error rate related to ECC errors.
Errors are counted as ECC errors
above a threshold. For the controller,
this attribute includes Uncorrectable
ECC (UECC) errors, and
Uncorrectable RAISE (URAISE)errors.
Normalized Equation:
10log10(BitsRead/ReadErrors + 1)
SectorsRead= Number of sectors read
SectorsToBits= 512*8
BitsRead= SectorsRead*SectorsToBits
Normalized Value Range:
Best = 130
Worst = 38
Invalid = 0
Raw Usage
includes two types of
ECC errors that are tracked by
the controller: UECC and
URAISE. The normalized
equation for Raw read error rate
is logarithmic since the valid
BER range of the attribute spans
from 1.00E-10 to 1.00E-12. To
force positive numbers, the
numerator and denominator
are flipped. One is then added to
the number of errors in the
denominator to avoid a
divide-by-0 condition if no errors
are encountered. By taking the
log of the inverted BER and
multiplying by ten a reasonable
range of normalized values from
130 to 38 (representing a BER
range of 1.00E-13 to
1.68E-04 ) are presented.
This Attribute reads ‘0’ until a
sample size between 10E10 and
10E12 is available to be
tracked by this Attribute.
:
[3-0] : Number of sectors read
[6-4]: Read errors (UECC+URAISE)
