SMART Attributes: Values, Thresholds and Historical Vendor-Specific Meanings

I. SMART Overview

SMART (Self-Monitoring, Analysis and Reporting Technology) exposes device health indicators and can help detect some developing failures, including wear or increasing media errors. Sudden electronic failure or impact can still occur without warning. It does not guarantee days or weeks of notice, an alarm at every boot, or enough time for recovery. Maintain backups independently. The source’s historical account traces IBM Predictive Failure Analysis to the IBM0662 SCSI drive and AS/400 in 1992; this is background, not a compatibility or prediction guarantee.

The source describes Compaq, Seagate, Quantum and Conner developing IntelliSafe, submission to the Small Form Factor committee in 1995, support from IBM and Western Digital, and a June 1996 revision 1.3 associated with SMART naming. Its practical theme is manufacturer-defined metrics and thresholds exposed to monitoring software. Device, firmware, transport/controller and software support determine which data and controls are available. A BIOS or monitoring tool may display a backup/replace-drive warning, but the exact message and alert delivery are not universal. The physical placement of firmware/service data is vendor-specific; the source’s fixed-track description is not a general access method. ATA SMART uses command B0h with subcommands: SMART RETURN STATUS is a health-status operation, not the command that retrieves every attribute. Reading attributes and logs are separate operations. Do not treat SMART information as an editable counter store or a self-repair guarantee.

 
II. SMART ID Codes

The source uses two-digit hexadecimal attribute IDs with decimal equivalents in parentheses. ATA attribute meanings, raw formats, units and availability depend on the drive model/firmware. They are not a mandatory universal set and do not form the NVMe or SCSI/SAS health-data schema. Its frequently discussed examples include 01(001) Raw Read Error Rate; 04(004) Start/Stop Count; 05(005) Reallocated Sectors; 09(009) Power-On Time; 0A(010) Spin-Up Retry; 0B(011) Calibration Retry; 0C(012) Power Cycle Count. Use a matching vendor reference or supported drive database.

　　C2 (194) Temperature 
　　C7 (199) Ultra DMA Parity Error Rate 
　　C8 (200) Write Error Rate

III. SMART Description

　　Description refers to the name of a specific test item and serves as a textual explanation of the ID code. For users, it is crucial not only to understand the meaning of descriptions but also to grasp definitions such as "Threshold," "Worst Value," and the distinction between "Current Value" and "Data Value." Only then can they gain a basic understanding of their hard drive's status.

IV. SMART Values

1. Threshold. This is the vendor-defined limit used with the attribute’s normalized value, where supported. Comparing a raw count directly with that threshold is usually incorrect. Attribute types, zero/unused thresholds and overall health status must be interpreted separately. The source quotes an unidentified read-error formula involving 10×log10, transferred sectors, 512×8 bits, re-read sectors and a 10^10–10^12 range, then claims a reset near 10^12 transfers. No model or vendor formula is identified, so this is not a usable conversion or a Windows reset rule. Do not calculate a drive’s failure probability from it.

2. Current / normalized value. The vendor derives this from device measurements. Common starting scales include 100, 200 or 253, but the scale, direction and interpretation depend on the attribute and model. A value may recover or vary (temperature is one example); not every attribute falls monotonically with age. A declining health indicator approaching its meaningful threshold warrants review, but it is not a universal remaining-life clock.

　　

3. Worst. This normally tracks the worst recorded normalized value for the particular vendor/attribute. On common higher-is-better scales it is the historical minimum, not the largest raw error count. It need not equal Current. Temperature and vendor-specific implementations require their own definitions; a difference alone does not prove a historical fault.

　　

4. Raw / Data value. This can be a cumulative count, instantaneous measurement, packed set of fields, vendor-encoded value or data needing conversion. Display tools can render decimal, hexadecimal or structured forms. The source examples of 50 start/stop cycles and 44°C are meaningful only for a matching direct-count or temperature format. Do not assume every raw temperature is one plain Celsius number, or that every large raw error-rate field is a simple count of failed operations.

V. Status

　　

Monitoring software may label an attribute or device Normal, Warning or Failed, but those three display labels are not one universal SMART status encoding. Read the device’s overall health result, attribute threshold status, error/self-test logs and observed trend separately. A passing health result does not certify that every sector is readable or that no failure is developing.

The ATA pre-failure/advisory flag classifies an attribute; it is not a bit that switches to 1 when a new failure occurs. For a meaningful threshold on the usual normalized scale, Current at or below Threshold is a threshold failure; Worst can indicate a past crossing. A tool’s warning about approaching a limit is a separate policy. The original bit0/bit1 three-state rule and strict-less-than-only test are therefore not a reliable decoder.

VI. Detailed Explanation of SMART Parameters

　　

The following preserves the source’s historical attribute catalog, including reused IDs for different controllers. Colors in the source distinguished selected HDD health items and SSD-specific entries; they are not authoritative failure classes. SLC means Single-Level Cell. MLC commonly denotes two bits per cell in this context, while other technologies such as TLC and QLC also exist. The source’s 100,000-cycle SLC/10,000-cycle MLC examples and 1,000,000-hour MTBF are historical illustrative claims, not universal NAND ratings or a mathematical consequence of wear leveling. Wear leveling spreads writes; actual endurance depends on NAND, controller, spare capacity and workload. SSD meanings without another attribution follow the source’s older SandForce context, not all current SSDs. Where the source explicitly says a meaning is unknown, it remains unknown here.

　　

01(001) Raw Read Error Rate. A vendor-defined read-error indicator. Some devices expose counts, while others pack operation/error fields; large Seagate raw values can be normal in that model’s format. Read the correct normalized interpretation and trend instead of requiring raw zero. The source associates its SandForce SSD variant with UECC and URAISE errors; that meaning is controller-specific.

RAISE expands to Redundant Array of Independent Silicon Elements, a vendor/controller-specific flash redundancy/recovery technique. It is an analogy to internal redundancy, not a replacement for external RAID, backups or a guarantee against data loss.

　　

02(002) Throughput Performance. The source describes a vendor-derived read/write performance indicator, sometimes absent or populated after an offline test. A lower normalized health value can be relevant where that vendor defines it; raw values are not universally higher-is-better and this field alone does not establish a severe fault.

　　

03(003) Spin-Up Time. On an HDD this relates to time to reach spindle speed; raw units and packed fields vary. The source gives 4–15 seconds as an illustration. A sustained change can justify checking power/mechanical behavior, while one slower spin-up is not a diagnosis. Some models report raw zero and use a normalized field. SSDs have no spindle; absence or reuse of this ID is possible, so do not require every SSD to report raw0/current100.

　　

04(004) Start/Stop Count. A supported HDD format counts spindle start/stop cycles, which can grow through idle-power policies without a defective motor. It differs from power-cycle count 0C, not Power-On Hours. The source’s unidentified example computes 100−(count/1024), with threshold 20: count 0 gives 100 and 81,920 gives 20. Retain that as an unverified model-specific example, not a general design-life formula. SSD use/absence of the ID must follow the model definition, not a fixed 0/100 rule.

　　

05(005) Reallocated Sectors Count / Retired Block Count. Firmware can retire an unreliable physical location and substitute spare capacity; the host continues addressing its logical sector. This can hide the retired physical location from an ordinary logical-sector scan, but does not prove that all original data was recovered. Review the actual count, growth, normalized health, tests and spare capacity. A threshold crossing does not universally prove that a G-list is full or that every spare is exhausted. Spares are not universally all at the end of the platter. Increasing reallocations can impair reliability/performance, but the source’s location explanation is not a general geometry rule. SSDs also retire blocks, including factory/runtime defects; interpret the matching vendor metric and trend. The source quotes 100−(100×replaced_blocks/required_blocks) as a health-like percentage, which is not a universal raw-count or remaining-life equation. Its legacy Intel example distinguishes 50nm first-generation from 34nm second-generation devices, citing SSDSA2M160G2GN. It claims a peculiar first-generation display mapping of 100 for 0–3 retired blocks, 1 for 4–7 and 2 for 8–11, versus a direct second-generation raw count. That mapping/model-generation shortcut is unverified here; use the exact Intel data sheet rather than applying it to another drive.

　　

　　06 (006) Read Channel Margin
　　The function of this item is unclear, and modern hard drives do not display this item.

07(007) Seek Error Rate. A model-specific seek-related indicator. Mechanical, servo, temperature or media behavior may influence it, but a raw zero requirement does not apply to every device. Large encoded Seagate values can occur on healthy drives; decode with the correct model definition and examine trend/context.

08(008) Seek Time Performance. A vendor-defined seek-performance indicator, sometimes absent. Interpret changes against that model’s normalized scale and tests; a decline alone is not a definitive diagnosis of the head, motor or servo.

09(009) Power-On Time / Hours(POH). This accumulates powered time in vendor-defined units, which can be hours, minutes, seconds or another interval such as 30 seconds. Its normalized aging field and threshold, if present, are model-specific. Do not subtract the count from population MTBF to estimate one drive’s remaining life: MTBF is not an individual countdown. The source says DIPM can change whether sleep time is counted on some SSDs; verify that behavior for the actual firmware rather than assuming a universal exclusion.

　　0A (010) Spin-Up Retry Count
　　The data value should be 0, and the current value should be greater than the threshold. 
　　The data value for Spin-Up Retry Count represents the number of times the spindle motor attempted to restart after failing to reach rated speed within the specified time following an initial start attempt. An increase in this data volume indicates issues with the motor driver circuit or mechanical subsystem; insufficient overall system power supply can also cause this problem.

　　0B (011) Calibration Retry Count
　　The data value should be 0, and the current value should be significantly higher than the threshold.
　　When temperature changes occur, mechanical components (especially platters) deform due to thermal expansion and contraction, necessitating head calibration to eliminate errors. Some drives also include built-in periodic head calibration functions. This item records the number of times recalibration was required (typically due to a previous calibration failure). 
　　An increase in this data volume indicates issues with the motor driver circuit or mechanical subsystem. However, some new drive models may show non-zero values without indicating a fault; therefore, the current value and worst-case value must also be considered.

　　0C (012) Power Cycle Count
　　The data value for Power Cycle Count represents the number of times the drive has been powered on/off, i.e., the cumulative count of power switch events. New drives typically show only a few counts. 
　　This item differs from the Start/Stop Count (04). Generally, powering on/off the drive corresponds to booting up/shutting down the computer, so the count increments by 1 only after a full cycle. In contrast, Start/Stop Count (04) tracks the spindle motor's start/stop cycles; the drive may start and stop multiple times during operation (e.g., when the system enters sleep mode or is configured to shut down after a period of idleness). Therefore, in most cases, the power-on/power-off count will be lower than the Start/Stop Count (04).

The source gives 5,000 power cycles as an example rating. Use the actual specification; a count or an illustrative rating alone does not predict a failure date.

0D(013) Soft Read Error Rate. The source ambiguously calls this both correctable errors and uncorrected errors reported to the OS. The name alone does not settle that distinction. Use the model’s definition before treating this raw field as recovered events or host-visible data failures.

　　AA (170) Grown Failing Block Count (Micron)
　　Total number of blocks that have failed read/write operations and are now marked as grown failing.

　　AB (171) Program Fail Block Count
　　Number of blocks that failed during flash programming.

　　AC (172) Erase Fail Block Count
　　Number of blocks that failed during erase operations.

　　AD (173) Wear Leveling Count / Average Erase Count (Micron)
　　Average number of erase operations performed on all good blocks. 
　　Flash chips have a limited write endurance. When using the FAT file system, frequent updates to the file allocation table are required. If certain areas of the flash memory are accessed too frequently, they will wear out faster than other areas, significantly shortening the overall drive life (even if erase counts in other areas remain far below the maximum limit). Therefore, ensuring uniform write distribution across the entire area extends chip life; this is known as the wear leveling mechanism.

　　AE (174) Unexpected Power Loss Count
　　Number of unexpected power loss events since the drive was enabled.

　　B1 (177) Wear Range Delta
　　Difference in wear percentage between the most worn block and the least worn block.

　　B4 (180) Unused Reserved Block Count Total (HP)
　　Solid-state drives reserve some capacity to replace damaged storage cells, making the count of available reserved space critical. The current value of this parameter represents the number of unused reserved storage cells.

　　B5 (181) Program Fail Count
　　Displays the number of program failures using 4 bytes; similar to parameter (AB).

 
　　B5 (181) Non-4k Aligned Access (Micron)

　　B6 (182) Erase Fail Count
　　Displays the number of block erase failures since the drive was enabled using 4 bytes; similar to parameter (AC).

　　B7 (183) SATA Downshift Error Count
　　This item indicates the number of times the SATA interface speed has degraded. Compatibility issues between the drive and the motherboard often cause SATA transmission levels to downgrade.

B8(184) has different source meanings. HP’s I/O Error Detection and Correction(IOEDC/SMARTIV) concerns integrity errors along the internal data path/cache path. The source’s Intel 34nm End-to-End Error Detection variant is likewise an internal-integrity indicator; do not reduce every instance to one logical-to-physical mapping error. For an Indilinx controller, the source labels it Init Bad Block Count, meaning factory defects. These meanings are alternatives selected by model, not three simultaneous readings of every B8 field.

　　B9 (185) Head Stability (Western Digital)
　　Meaning unclear.

　　BA (186) Induced Op-Vibration Detection (Western Digital)
　　Meaning unclear.

　　BB (187) Reported Uncorrectable Errors (Seagate)
　　Errors reported to the operating system that cannot be corrected by hardware ECC. If the data value is non-zero, back up the data on the hard drive immediately. 
　　URAISE (Unrecoverable Asynchronous Interface Synchronization Error) errors reported to the operating system occurring during all access commands.

　　BC (188) Command Timeout
　　Number of times operations were terminated due to a hard drive timeout. Typically, the data value should be 0. If it is significantly greater than zero, the most likely causes are power supply issues or poor contact caused by oxidation of the data cable; alternatively, the hard drive may have serious problems.

　　BD (189) High Fly Writes
　　The head fly height monitoring device improves read/write reliability. This device continuously monitors whether the head's fly height is within the normal range to ensure reliable data writing. If the head's fly height deviates, the write operation stops, then attempts to rewrite or writes to a different location. This continuous monitoring process improves the reliability of written data and also reduces the read error rate. This item counts the number of times the head's fly height deviated during writes.

 　　BD (189) Factory Bad Block Count (Micron Chip)

　　BE (190) Airflow Temperature
　　This item represents the airflow temperature on the surface of the platters inside the hard drive. In some Seagate drives, Current Value = (100 - Current Temperature); therefore, the higher the airflow temperature, the lower the current value. The Minimum Value is the lowest point the current value has ever reached. The Threshold Value is determined by the maximum allowable temperature defined by the manufacturer, while the Raw Data Value has no practical meaning. Many drives do not have this parameter.

　　BF (191) G-Sense Error Rate
　　The data value for this item records the frequency of errors caused by mechanical shocks to the hard drive.

C0(192) Power-Off Retract Count. This HDD field can count emergency head retractions or other power-management-related events, depending on the vendor. Some formats stay near zero; others can exceed 0C power cycles or 04 start/stops while remaining below C1 load cycles. SSDs may reuse a corresponding field for unsafe shutdowns. The source equates Standby Immediate with flushing data, which is too broad: a spin-down command is not a general guarantee that volatile data has been made durable. Follow the supported shutdown/cache-flush behavior of the actual stack.

C1(193) Load/Unload Cycle Count. This counts head load/unload activity in an applicable HDD format. The source contrasts older contact-start/stop parking with modern ramp loading outside the platter. Ramp loading reduces contact-related wear but does not make the mechanism unlimited or risk-free. Energy-saving policies can park the head repeatedly while the drive remains powered, so this can exceed 0C power cycles and 04 start/stops. The source cites 300,000–600,000 cycles for some laptop drives and 1,000,000 for some desktop designs. Those are historical examples, not ratings for the actual disk; investigate an abnormal rate using its specification and workload.

C2(194) Temperature. Decode the correct Celsius/packed/raw and normalized fields for the model. The source’s 45°C preference and roughly 60°C maximum are examples, not universal limits. Excess temperature can affect reliability and data integrity; do not accept its claim that overheating cannot cause data loss. The source describes some Seagate formats as using actual Celsius for Current and some Western Digital formats as inverse-temperature/time-related normalized values. Verify those details for the actual firmware instead of transferring one vendor’s scale to another.

C3(195) has several source meanings: Hardware ECC Recovered on an HDD; On-the-Fly ECC Uncorrectable Error Count on certain SSD controllers; and Program Failure Block Count on Indilinx. ECC means error-correcting code. Corrected-event counts and host-unrecoverable errors are different; a large packed ECC field alone is not a failed-drive test.

C4(196) Reallocation Events Count commonly tracks attempts/events related to reassignment, which need not equal the number of sectors in 05. Success/failure accounting is vendor-defined. The source’s Indilinx alternative is Erase Failure Block Count; its accompanying programming-failure wording conflicts with that label, so use the matching controller reference rather than merging erase and program metrics.

C5(197) Current Pending Sector Count commonly tracks suspect/unreadable sectors awaiting a firmware decision. A successful later read can clear a pending condition; reassignment can also change this count and 05/C4 as appropriate. The precise reassignment trigger is firmware-specific, so the source’s “only after a failed write” rule is not universal. Do not overwrite a sector merely to force a cosmetic count change. Its Indilinx alternative is Read Failure Block Count(unrecoverable errors), a distinct model-defined metric.

C6(198) Offline Uncorrectable Sector Count reflects uncorrectable conditions detected by the applicable offline scan/test. It is not necessarily the count of all lifetime read/write errors, and an increase does not identify a specific FRU or guarantee automatic repair on the next write. Correlate unreadable data, self-tests and other errors. The source’s Indilinx alternative is Total Count of Read Sectors, so C6 cannot be decoded from the ID alone.

C7(199) Ultra ATA / UDMA CRC Error Count commonly indicates interface-transfer CRC errors. Increasing counts suggest checking the complete link, cable, connectors, power/controller and device context; it is not proof of failed media. Historical counts often remain after a repair, so compare the rate after the change. Counter reset/persistence is model-specific. The source’s Indilinx alternative is Total Count of Write Sectors, not a CRC counter.

C8(200) Write Error Rate / Multi-Zone Error Rate(Western Digital source interpretation). The source associates growth or a falling normalized value with write/media/head issues, but raw scaling and diagnostic meaning are vendor-specific. Some devices have nonzero values from early life. The Indilinx alternative is Total Count of Read Commands; do not interpret a command total as a fault count.

C9(201) Off-Track Error Rate / Soft Read Error Rate has a model-specific interpretation. Correlate errors and maintain backups; the ID alone does not prove off-track head failure. The source also lists TA Counter Detected with meaning unknown, and the Indilinx Total Count of Write Commands as another variant.

CA(202) includes the source variants Data Address Mark Errors; TA Counter Increased(unknown meaning); Micron Percentage of the Rated Lifetime Used; and Indilinx Total Count of Error Bits from Flash. For the Micron case, distinguish a raw percentage-used measure from a normalized remaining-health scale. The source quotes a normalized 100→0 illustration, 5000 MLC cycles with a divisor 50, and 100000 SLC cycles with a divisor 1000. These are unidentified historical parameters, not a universal lifetime conversion. Use the exact model/firmware documentation and do not confuse used with remaining.

　　CB (203) Run Out Cancel
　　Frequency of errors occurring during error checking and correction (ECC). 
　　CB (203) Total Count of Read Sectors with correct bits error

　　CC (204) Soft ECC Correction
　　Count of errors corrected via software ECC. 
　　CC (204) Bad Block Full Flag

CD(205) Thermal Asperity Rate(TAR) is a model-defined head/media-related error indicator. The source simplifies it to errors from overheating; that is not a sufficient generic diagnosis. Its Indilinx alternative is Max P/E Count(maximum program/erase count), not the same measurement.

CE(206) includes Flying Height, a vendor-specific head/platter-related indicator; an alternative Write Error Rate; and Indilinx Erase Count Min. Do not convert the raw field into a physical head-to-platter distance without the vendor’s definition, or assume every device measures/derives it in the same way.

　　CF (207) Spin High Current
　　The data value records the number of times surge current occurred during spindle motor operation. An increase in data volume suggests potential issues with the bearings or the motor. 
　　CF (207) Maximum Erase Count (Indilinx Chip)

D0(208) Spin Buzz is the source’s spindle-start/retry-related label, distinct from the 0A spin-up-retry identifier. Repeated activity can have power or mechanical causes, but it is not a diagnosis by itself. The Indilinx alternative is Erase Count Average.

　　D1 (209) Offline Seek Performance
　　This item indicates the seek performance of the drive in an offline state, typically used for internal factory testing. 
　　D1 (209) Remaining Life Percentage (Indilinx Chip)

　　D2 (210) Ramp Load Value
　　This item is only found on some hard drives manufactured by Maxtor several years ago. The data value is usually 0 and its meaning is unclear. 
　　D2 (210) BBM Error Log (Indilinx Chip)

　　D3 (211) Vibration During Write
　　Records external vibrations encountered while writing data. 
　　D3 (211) SATA Host Interface CRC Error Count (Write) (Indilinx Chip)

　　D4 (212) Shock During Write
　　Records external mechanical shocks encountered while writing data. 
　　D4 (212) SATA Host Interface Read Error Count (CRC) (Read) (Indilinx Chip)

　　DC (220) Disk Shift
　　The offset of the disk platters relative to the spindle axis within the hard drive (usually caused by external shock or temperature changes). The unit is unknown; a smaller data value is better.

　　DD (221) G-sense Error Rate
　　Same as (BF). The data value records the frequency of errors caused by external mechanical shocks or vibrations affecting the hard drive.

　　DE (222) Loaded Hours
　　The cumulative hours of operation for the actuator arm assembly, i.e., the total time the seek motor has been running.

　　DF (223) Load/Unload Retry Count
　　Similar to item (C1), this data value accumulates the number of times the head attempted to reload/unload.

　　E0 (224) Load Friction
　　The mechanical resistance encountered by the head during operation.

E1(225) Host Writes counts host writes for applicable SSD formats. The source’s Intel example increments after 65536 sectors and mentions the historical Intel SSD Toolbox displaying a converted amount. Confirm logical-sector size and counter units before converting; “host writes” is not exclusively an SSD concept and this scale is not universal. The original old Toolbox link is retained only as source context, not a current utility recommendation.

　　E2 (226) Load 'In'-time
　　The cumulative count of time the head assembly has been active, i.e., the time the actuator arm was not in the parked zone, similar to item (DE).

　　E3 (227) Torque Amplification Count
　　The number of times the spindle motor attempts to increase torque to compensate for changes in disk rotation speed. When spindle bearing issues exist, the motor tries to increase driving force to stabilize disk rotation. A decrease in the current value of this parameter indicates severe problems in the hard drive's mechanical subsystem.

　　E4 (228) Power-Off Retract Cycle
　　The data value accumulates the number of times the heads automatically retracted due to unexpected device power loss, similar to item (C0).

E6(230) GMR Head Amplitude is the source’s historical label. Its explanation as a physical head-jitter distance is not verified; do not infer motion/distance units from this raw value.

E7(231) can be Temperature in one format or SSD Life Left in another. The source’s SandForce-context example describes100 for new, 10 at a designed P/E limit with spares remaining, and 0 with insufficient spares/read-only behavior. Those values and transition behavior require the exact controller/firmware documentation;0does not universally guarantee read-only protection or safe recovery. Backups remain necessary.

E8(232) includes Endurance Remaining in one format and Intel Available Reserved Space in another. Do not confuse consumed endurance with remaining endurance or spare blocks. The source’s Intel example starts at 100 and cites a threshold around 10, but neither a direct percentage interpretation nor that threshold applies to all models. Evaluate alongside 05 and other health fields; one ID is not universally the single most important measure.

E9(233) can mean Power-On Hours, analogous to 09, or Intel Media Wearout Indicator. The source’s Intel example uses a normalized decline from 100 to 1 with NAND wear. A design-endurance indication is not a promised immediate failure date and does not certify that another drive will fail in the same way. Check actual vendor units, limits and warranty/endurance metrics.

　　Note: Total Erase Count refers to the sum of erase counts for all blocks in the solid-state drive. Different specifications of NAND chips and different capacities of SSDs have different maximum total erase counts.

　　F0 (240) Head Flying Hours / Transfer Error Rate (Fujitsu)
　　Time during which the head is in the operating position. 
　　For Fujitsu drives, this indicates the number of times the connection was reset during data transfer.

F1(241) Total LBAs Written accumulates host-write units where that is the model definition. The source’s alternative Lifetime Writes from Host describes a four-byte counter with one unit per 64GB written; despite its translated label, it is a lifetime total, not remaining write capacity. Units can differ across vendors and must be verified.

F2(242) Total LBAs Read accumulates host-read units where defined. The source also describes a four-byte Lifetime Reads from Host counter with 64GB per unit, a cumulative amount rather than remaining life. A negative display can indicate a decoder/signedness/format problem; a 48-bit counter is not inherently negative. Use software that correctly supports the actual raw format.

　　FA (250) Read Error Retry Rate
　　Number of errors occurring when reading from the disk.

　　FE (254) Free Fall Protection
　　Some laptop hard drives now have free fall protection functionality. When the built-in acceleration detection device detects movement of the drive, it immediately stops read/write operations and resets the head arm. This measure prevents friction and impact between the head and the platter, improving the drive's shock resistance. The data value for this parameter records the number of times this protection device has been activated.