ID
Name
Raw value is better when*
Description**
1
Raw Read Error Rate
Lower
Represents the rate of uncorrected read errors
2
Throughput Performance
Higher
Represents the throughput performance of the drive. I.e. The speed at which the drive is reading and writing data.
3
Spin Up Time
Lower
Represents the average amount of time required to spin up the drive spindle to operational speed from a stopped state.
4
Start/Stop Count
Lower
Represents the number of start/stop cycles for the drive. The raw value indicates the count of start/stop cycles for the drive. The drive being powered on/off or suspended/woken up are considered as start/stop cycles.
5
Reallocated Sector Count
Lower
Represents the amount of spare sector pool available. Spare sectors are used to replace sectors that became bad for some reason (for instance, if a read error occurs). Therefore the more sectors reallocated, the worse the condition of the drive.
7
Seek Error Rate
Lower
Represents the number of seek errors. Each time the drive attempts a seek operation, but fails to position its head correctly, the seek error rate increases.
8
Seek Time Performance
Higher
Represents how efficiently the drive is performing seek operations. A low value indicates problems with the drive subsystem, for instance the servo responsible for positioning the head.
9
Power On Hours Count
Higher
This is an informative attribute, the raw value of which displays the number of hours the drive has been powered on for.
A
Spin Retry Count
Lower
Represents the number of times a drive fails to spin its spindle up to operation speed on the first attempt.
B
Calibration Retry Count
Higher
Calibration is the act of repositioning the drive read/write head to cylinder 0. This value represents the number of times a calibration has failed on the first attempt.
C
Power Cycle Count
Lower
Informative attribute, the raw value of which represents the number of drive power on/drive power off cycles for the disk.
D
Soft Read Error Rate
Lower
Uncorrected read errors reported to the operating system.
BE
Temperature Difference from 100
Unkown
The exact specification of this attribute is not quite stable. This is what it is known as on Seagate drives whereas it is called Airflow Temperature on Western Digital hard disks. In either case this attribute usually has to do with subtracting the temperature from 100 to give a value that is worse when it is lower.
BF
G-Sense Error Rate
Lower
Frequency of mistakes as a result of impact loads
C0
Power-off Retract Count
Lower
Number of times the heads are loaded off the media. Heads can be unloaded without actually powering off.
C1
Load/Unload Cycle
Lower
Count of load/unload cycles into head landing zone position.
C2
Temperature
Lower
Informative attribute, the raw value of which represents the current temperature in Celsius of the drive.
C3
Hardware ECC Recovered
Higher
Time between ECC-corrected errors.
C4
Reallocation Event Count
Lower
Represents the number of reallocation events, which have taken place. Sometimes multiple sectors are reallocated together – this corresponds to one reallocation event. (See also:
Reallocated Sector Count and
Current Pending Sector Count).
C5
Current Pending Sector Count
Lower
Represents the number of sectors currently pending reallocation.
C6
Uncorrectable Sector Count
Lower
The total number of uncorrectable errors when reading/writing a sector.
C7
UltraDMA CRC Error Count
Lower
Represents the number of CRC error found in the Ultra DMA high-speed transfer mode. (CRC stands for Cyclic Redundancy Check and is data verification algorithm which uses polynomial checksums).
C8
Write Error Count
Lower
Represents the rate of uncorrected write errors. Lower raw values indicate that there is a problem with either disk surface or read/write heads.
C9
Soft Read Error Rate
Lower
Number of off-track errors.
CA
Data Address Mark errors
Lower
Number of Data Address Mark errors
CB
Run Out Cancel
Lower
Number of ECC errors
CC
Soft ECC Correction
Lower
Number of errors corrected by software ECC.
CD
Thermal asperity rate(TAR)
Lower
Number of thermal asperity errors.
CE
Flying Height
Unknown
Height of heads above the disk surface.
CF
Spin High Current
Unknown
Amount of high current used to spin up the drive.
D0
Spin Buzz
Unknown
Number of buzz routines to spin up the drive
D1
Offline Seek Performance
Unknown
Drive’s seek performance during offline operations
DC
Disk Shift
Lower
Distance the disk has shifted relative to the spindle (usually due to shock).
DD
G-Sense Error Rate
Lower
The number of errors resulting from externally-induced shock & vibration.
DE
Loaded Hours
Lower
Time spent operating under data load (movement of magnetic head armature)
DF
Load/Unload Retry Count
Unknown
Number of times head changes position.
E0
Load Friction
Lower
Resistance caused by friction in mechanical parts while operating.
E1
Load/Unload Cycle Count
Lower
Total number of load cycles
E2
Load 'In'-time
Unknown
Total time of loading on the magnetic heads actuator (time not spent in parking area).
E3
Torque Amplification Count
Unknown
Number of attempts to compensate for platter speed variations
E4
Power-off Retract Count
Lower
The number of times the magnetic armature was retracted automatically as a result of cutting power.
E6
GMR Head Amplitude
Unknown
Amplitude of "thrashing" (distance of repetitive forward/reverse head motion)
E7
Temperature
Unknown
Drive Temperature, unknown units.
F0
Head Flying Hours
Unknown
Time while head is positioning
FA
Read Error Retry Rate
Lower
Number of errors while reading from a disk
