Method and device for obtaining average fault interval time of solid state disk
By using the accelerated life test model and JEDEC218 standard, the testing conditions are scientifically selected, and the problems of large sample volume and long test cycle in the MTBF test of solid-state drives are solved, achieving fast and efficient MTBF prediction and testing.
Patent Information
- Application Number
- CN202411428836.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-12
- Publication Date
- 2025-02-28
AI Technical Summary
When calculating the average failure interval time (MTBF) of a solid state hard disk, the sample volume is large and the test cycle is long, resulting in high costs.
Accelerated life test models, such as the Alenius model, combined with the JEDEC218 standard, scientifically select the test temperature, sample number and test duration, and shorten the test cycle and reduce the sample volume through high-temperature accelerated testing.
Quickly predict the average failure-free time of SSD under normal use conditions, shortens the test cycle, reduces costs, and improves test efficiency.
Smart Images
Figure CN119541595A_ABST
Abstract
Description
Technical Field
[0001] The present application relates to, but is not limited to, the field of storage device testing technology, and specifically to a method and device for obtaining a mean time between failures of a solid state drive. Background Art
[0002] The industry's Mean Time Between Failures (MTBF) indicator reflects the product's trouble-free continuous operation time and is an important indicator for evaluating product reliability. The calculation of MTBF is based on some standards. The most commonly used and authoritative standards currently include MIL-HDBK-217, GJB / Z299B and Bellcore. Among them, MIL-HDBK-217 was developed by the U.S. Department of Defense Reliability Analysis Center and Rome Laboratory, and has now become an industry standard, mainly used for calculating the MTBF value of military products. GJB / Z299B is a Chinese military standard, used for calculating the MTBF value of domestic military products; Bellcore was developed by AT&T Bell Laboratories and has now become an industry standard for calculating the MTBF value of commercial electronic products.
[0003] The calculation of MTBF mainly considers the failure rate of each component in the product. Since the failure rate of components varies greatly in different environments and usage conditions, the reliability of the same product in different environments (such as laboratories and offshore platforms) may be completely different. In addition, a capacitor with a rated voltage of 16V has a significant difference in failure rate when the actual voltage is 25V and 5V. Therefore, these factors must be considered comprehensively when calculating reliability indicators. Due to the complexity of these factors, manual calculation is almost impossible, but the MTBF value can be easily obtained with the help of software (such as MTBFcal software) and its huge parameter library.
[0004] For solid state drives (SSDs), the JESD218A standard provides a specific method for testing SSDs, specifies how to measure the daily read and write volume of SSDs, and specifies how to perform additional failure tests. When evaluating the MTBF of an SSD, a key factor is the workload used during the test, that is, how much data the SSD needs to read and write every day during the test, which directly affects the final MTBF value. For example, a standard SSD can achieve an MTBF of 1.2 million hours under a workload of writing 20GB of data per day and running continuously for 5 years, combined with a supplementary failure test. However, if the workload is reduced to writing 10GB of data per day, the MTBF may rise to 2.5 million hours; and in the case of writing 5GB of data per day, the MTBF can be further increased to 4 million hours. This shows that the MTBF of an SSD is not only affected by its own quality, but also closely related to the actual usage conditions, so the specific usage scenarios and load conditions must be considered in the evaluation. Summary of the invention
[0005] The present application provides a method and device for obtaining the mean time between failures of a solid-state hard disk, which can reduce the sample size, shorten the test cycle, and thus reduce costs.
[0006] An embodiment of the present invention provides a method for obtaining a mean time between failures of a solid state drive, comprising:
[0007] Determine the test conditions using the accelerated life test model based on the test objectives;
[0008] Run SSD samples under defined test conditions to estimate their mean time between failures.
[0009] In one exemplary embodiment, the accelerated life test model includes an Arrhenius model.
[0010] In an exemplary embodiment, the test targets include: temperature and load.
[0011] In an exemplary embodiment, the test conditions include: temperature, sample quantity, and test duration.
[0012] In an exemplary embodiment, the Arrhenius model is used to determine the test conditions for achieving the test target; the Arrhenius model is:
[0013]
[0014] Where AF is the acceleration factor, which is used to convert the test results under high temperature into the predicted results under normal temperature conditions; E a represents the activation energy, which represents the sensitivity of temperature to failure rate; k represents the Boltzmann constant; T1 and T 2 Represent the absolute temperatures at room temperature and accelerated test temperature respectively.
[0015] In an exemplary embodiment, the accelerated test temperature is 55°C, 60°C or 70°C.
[0016] In an exemplary embodiment, the running of the SSD sample to estimate its mean time between failures:
[0017] Run the SSD sample in a normal environment and an accelerated environment respectively, and record the time when each failure occurs;
[0018] The failure time of each SSD sample is recorded and the working time of the device is calculated; the collected failure data is statistically analyzed to calculate the value of the mean time between failures.
[0019] In an exemplary embodiment, NAND patch graphene heat dissipation armor technology is used in the SSD sample to improve the heat dissipation capability.
[0020] An embodiment of the present application further provides a computer-readable storage medium storing computer-executable instructions, wherein the computer-executable instructions are used to execute any of the above methods for obtaining the mean time between failures of a solid-state drive.
[0021] An embodiment of the present application further provides a computer device, including a memory and a processor, wherein the memory stores the following instructions executable by the processor: used to execute the steps of any of the above-mentioned methods for obtaining the mean time between failures of a solid-state drive.
[0022] The embodiment of the present application also provides a device for obtaining the mean time between failures of a solid state drive, comprising: a determination module and a test module; wherein:
[0023] A determination module, used to determine the test conditions using an accelerated life test model according to the test objectives;
[0024] A test module for running SSD samples under certain test conditions to estimate their mean time between failures.
[0025] In an exemplary embodiment, the accelerated life test model includes: an Arrhenius model.
[0026] In an exemplary embodiment, the accelerated test temperature T in the Arrhenius model 2 Including 55℃, 60℃ or 70℃.
[0027] In an exemplary embodiment, NAND chip graphene heat dissipation armor technology is used in the SSD sample.
[0028] Through the method and device for obtaining the mean time between failures of solid-state drives provided in the embodiments of the present application, the acceleration factor is calculated using an accelerated life test model such as the Arrhenius model, and the test conditions such as the test temperature, the number of samples, and the test duration are scientifically selected in combination with the requirements of the JEDEC218 standard for confidence and the number of samples. This method not only quickly predicts the mean time between failures of the SSD under normal use conditions, but also greatly shortens the test cycle and improves the test efficiency through high-temperature accelerated testing, and greatly reduces the number of test samples, thereby reducing costs.
[0029] Other features and advantages of the present invention will be described in the following description, and partly become apparent from the description, or understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures particularly pointed out in the description, claims and drawings. BRIEF DESCRIPTION OF THE DRAWINGS
[0030] The accompanying drawings are used to provide further understanding of the technical solution of the present application and constitute a part of the specification. Together with the embodiments of the present application, they are used to explain the technical solution of the present application and do not constitute a limitation on the technical solution of the present application.
[0031] Figure 1 A flowchart of a method for obtaining the mean time between failures of a solid state drive in an embodiment of the present application;
[0032] FIG. 2( a ) is a schematic diagram of a heat dissipation structure of an SSD in a first direction according to an embodiment of the present application;
[0033] FIG. 2( b ) is a schematic diagram of the heat dissipation structure of the SSD in the second direction according to the embodiment of the present application;
[0034] FIG2( c ) is a schematic diagram of the heat dissipation structure of the SSD in the embodiment of the present application from a third direction;
[0035] FIG2( d ) is a schematic diagram of the heat dissipation structure of the SSD in the fourth direction according to the embodiment of the present application;
[0036] Figure 3 Schematic diagram of a device for obtaining the mean time between failures of a solid state drive in an embodiment of the present application. DETAILED DESCRIPTION
[0037] In order to make the purpose, technical solution and advantages of the present application more clear, the embodiments of the present application will be described in detail below with reference to the accompanying drawings. It should be noted that the embodiments and features in the embodiments of the present application can be combined with each other arbitrarily without conflict.
[0038] In order to facilitate understanding of the present application, the present application will be described more fully below with reference to the relevant drawings. Embodiments of the present application are provided in the drawings. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present application more thorough and comprehensive.
[0039] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application.
[0040] It is understood that the terms "first" and "second" used in this application are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of this application, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.
[0041] It can be understood that the “connection” in the following embodiments should be understood as “electrical connection”, “communication connection”, etc. if the connected circuits, modules, units, etc. have electrical signals or data transmission between each other.
[0042] When used herein, the singular forms "a", "an", and "said / the" may also include plural forms, unless the context clearly indicates otherwise. It should also be understood that the terms "include / comprise" or "have" and the like specify the presence of stated features, wholes, steps, operations, components, parts, or combinations thereof, but do not exclude the possibility of the presence or addition of one or more other features, wholes, steps, operations, components, parts, or combinations thereof. At the same time, the term "and / or" used in this specification includes any and all combinations of the relevant listed items.
[0043] The purpose of MTBF testing is to verify the reliability of SSDs under specific usage conditions. By conducting long-term tests under different temperatures, loads, and working conditions, the average time between failures of the device is evaluated, thereby predicting its reliability performance in actual use.
[0044] Figure 1 Flow chart of a method for obtaining the mean time between failures of a solid state drive in an embodiment of the present application, such as Figure 1 As shown, including:
[0045] Step 100: Determine test conditions using an accelerated life test model according to test objectives.
[0046] In an exemplary embodiment, the accelerated life test model may include, but is not limited to, an Arrhenius Model, which is used to simulate and predict the effect of temperature changes on device failure rates.
[0047] In an exemplary embodiment, the test target may include but is not limited to: temperature, load, etc. In one embodiment, in the test, the target is to verify the reliability of the SSD in different environments, such as: temperature, which is used to test the performance of the SSD in a high temperature environment and confirm its heat resistance; load, which is used to simulate the use of the SSD under high read and write loads.
[0048] In an exemplary embodiment, the test conditions include: temperature, sample quantity, and test duration.
[0049] In one embodiment, the Arrhenius model can be used to determine the test conditions for achieving the test target. The formula of the Arrhenius model can be shown as formula (1):
[0050]
[0051] In formula (1), the acceleration factor (AF) is used to convert the test results under high temperature into the predicted results under normal temperature conditions; E a represents the activation energy, which represents the sensitivity of temperature to failure rate and can be 1.0 eV; k represents the Boltzmann constant and can be 0.00008617 electron volts / Kelvin (eV / °K); T 1 and T 2 Represents the absolute temperature at room temperature and accelerated test temperature (in Kelvin).
[0052] In one embodiment, according to the Arrhenius model shown in formula (1), a suitable high temperature test environment, such as 55°C, 60°C or 70°C, is selected as the accelerated test temperature T 2 , in order to accelerate the aging process of SSD. Accelerated test temperature T 2 T 1 (e.g. 25°C) higher, the test time can be shortened. The number of samples to be tested needs to be determined based on statistical requirements. For example, 64 SSDs are selected as samples to ensure that the test results are statistically representative. The test time is related to the acceleration factor AF calculated by formula (1). The Arrhenius model is used to calculate the accelerated test temperature T under accelerated conditions. 2 The required test duration is as follows.
[0053] For example, if the room temperature is 30℃, that is: T 1=30+273.15=303.15K, the accelerated test temperature is 60℃, that is: T 2 =60+273.15=333.15K, for example, E a =1.0eV, k=0.00008617eV / °K, e=2.718, and substituting into formula (1) yields AF≈31.4. This means that when tested at an accelerated test temperature of 60°C, the aging rate of the SSD is 31.4 times that at a normal temperature of 30°C. In other words, the high temperature environment accelerates the failure process of the SSD, thereby simulating the long-term performance of the device at standard temperature in a relatively short period of time.
[0054] The JEDEC218 standard, one of the standards for SSD reliability testing, specifies test methods, failure criteria, and confidence analysis. According to the JEDEC218 standard, the confidence level is set to 60%, which means that there is a 60% chance of ensuring the accuracy of the test results. In the confidence analysis, the upper confidence limit (UCL) value is used to determine the statistical range of the failure test results. In this embodiment, the UCL is 0.92, which means that there is a 92% confidence range to evaluate the failure data. The number of failures (Failures) is 0, indicating that no failures of the SSD samples were detected during the test. In order to provide sufficient data for statistical analysis, the test sample size can be 64 pieces (such as 32 pieces each for 1TB and 2TB).
[0055] When the high temperature environment is set to 60°C, the temperature chamber is maintained at this temperature for accelerated testing, so that the SSD failure data under normal temperature conditions can be quickly obtained through the acceleration factor. The MTBF target is 1.5 million hours, which represents the expected average failure-free time of the SSD at normal temperature. Since the acceleration factor in the high temperature environment is 31.4, the MTBF of the device can be predicted by converting the test time at high temperature into the equivalent time at normal temperature.
[0056] Taking the test at 60°C for 746 hours as an example, since the acceleration factor is 31.4, this is equivalent to: at room temperature: equivalent test time = 746 × 31.4 = 23444 hours. In this way, through accelerated testing in a high temperature environment, the reliability prediction of running for a longer time at room temperature can be quickly obtained, thereby verifying whether the target value of MTBF can be achieved. Combined with the case where the number of failures is 0, the equivalent MTBF at room temperature is estimated by the acceleration factor and the actual test duration to ensure that the target of 1.5 million hours is achieved. In the embodiment of the present application, by using an accelerated life test model (also called a temperature acceleration model), the acceleration factor under different test conditions is calculated, and the test results under accelerated conditions are converted into reliability indicators under normal operating conditions.
[0057] In the embodiment of the present application, the acceleration factor is calculated using an accelerated life test model such as the Arrhenius model, and the test conditions such as the test temperature, the number of samples, and the test duration are scientifically selected in combination with the requirements of the JEDEC218 standard for confidence and the number of samples. This method not only quickly predicts the mean time between failures of the SSD under normal use conditions, but also greatly shortens the test cycle and improves the test efficiency through high temperature accelerated testing, and greatly reduces the number of test samples, thereby reducing costs.
[0058] Step 101: Run an SSD sample under determined test conditions to estimate its mean time between failures.
[0059] In an exemplary embodiment, step 101 may include:
[0060] Run the SSD samples in normal and accelerated environments, and record the time when each failure occurs. Here, the accelerated test phase is used to speed up the failure so that reliability data can be obtained in a shorter time.
[0061] The failure time of each SSD sample is recorded to calculate the working time of the device; the collected failure data is statistically analyzed to calculate the MTBF value.
[0062] In an exemplary embodiment, further, NAND patch graphene heat dissipation armor technology can be used in SSD samples. Taking advantage of the high thermal conductivity of graphene, the graphene material is attached to the NAND chip to form a heat dissipation layer or "armor" to improve the heat dissipation capability.
[0063] The design in the embodiment of the present application achieves more efficient heat conduction and dissipation by covering the surface of the NAND flash memory chip with a layer of graphene material. Since graphene has an extremely high thermal conductivity, it can quickly dissipate the heat generated by the NAND chip, thereby reducing the temperature of the chip surface. This heat dissipation design ensures that the SSD can maintain an appropriate operating temperature when it is under high load or running for a long time, avoiding excessive temperature.
[0064] NAND flash memory chips usually have a safe operating temperature range. Exceeding this range may cause performance degradation or damage. The heat dissipation design provided in the embodiments of the present application ensures that the temperature of the NAND chip is always below this threshold. The SSD can dissipate heat more efficiently during operation and remain within the safe temperature range of the NAND chip, avoiding the risk of overheating, improving overall performance and stability, thereby extending the service life of the SSD and ensuring its stability.
[0065] In one embodiment, the heat dissipation structure of the SSD adopts a design similar to that of a heat sink, and has a compact structure. The dense fin structure is conducive to increasing the heat dissipation area, thereby improving the heat dissipation efficiency. Figure 2(a)-Figure 2(d) As shown in the figure, it is attached to the surface of the NAND chip in the SSD to form a heat dissipation "armor", such as Figure 2(a)-Figure 2(d) The part of the SSD that is covered on the NAND flash memory and other important components. This design ensures that when the SSD is running at high load, the heat can be quickly conducted away by the heat sink and the graphene layer to prevent the temperature from exceeding the temperature threshold of the NAND chip. In this embodiment, the SSD component has a compact structure and a good heat sink arrangement. Combined with the use of graphene, it helps to ensure that the SSD maintains a suitable temperature range during long-term operation, thereby improving performance and extending service life.
[0066] Through experiments combined with theoretical verification, the method for obtaining the mean time between failures of a solid-state drive provided in an embodiment of the present application reasonably increases the temperature of the SSD test environment while ensuring sufficient wear of the program / erase cycles (PE). In this way, the sample quantity is reduced, the test cycle is shortened, and the manufacturing cost and time cost are greatly reduced. In one embodiment, for consumer-grade SSDs, the temperature of the SSD test environment can be increased to 60°C; for industrial-grade SSDs, the temperature of the SSD test environment can be increased to 70°C. At these temperatures, the PE wear of the SSD can meet the corresponding test standards, accelerate the aging process at high temperatures, and shorten the test cycle. On the other hand, according to the Arrhenius model, the required sample quantity can be calculated through the acceleration factor under high temperature conditions, further reducing the number of samples required for testing, thereby effectively reducing the test cost.
[0067] The present application also provides a computer-readable storage medium storing computer-executable instructions, wherein the computer-executable instructions are used to execute any of the above methods for obtaining the mean time between failures of a solid-state drive.
[0068] An embodiment of the present disclosure further provides a computer device, including a memory; and a processor connected to the memory, wherein the processor executes the steps of the method for obtaining the average failure interval between solid-state drives as described in any of the preceding items based on instructions stored in the memory.
[0069] Figure 3 Schematic diagram of a device for obtaining the mean time between failures of a solid state drive in an embodiment of the present application, such as Figure 3 As shown, it may include: a determination module and a test module; wherein,
[0070] A determination module, used to determine the test conditions using an accelerated life test model according to the test objectives;
[0071] A test module for running SSD samples under certain test conditions to estimate their mean time between failures.
[0072] In an exemplary embodiment, the accelerated life test model may include, but is not limited to, an Arrhenius model. In an embodiment, the Arrhenius model may be used to determine the test conditions for achieving the test objectives. In an embodiment, the accelerated test temperature T in the Arrhenius model 2 Including but not limited to 55°C, 60°C or 70°C.
[0073] In an exemplary embodiment, the test target may include, but is not limited to, temperature, load, and the like.
[0074] In an exemplary embodiment, the test conditions include: temperature, sample quantity, and test duration.
[0075] In one exemplary embodiment, the test module may be used to:
[0076] Run the SSD samples in normal and accelerated environments, and record the time when each failure occurs. Here, the accelerated test phase is used to speed up the failure so that reliability data can be obtained in a shorter time.
[0077] The failure time of each SSD sample is recorded to calculate the working time of the device; the collected failure data is statistically analyzed to calculate the MTBF value.
[0078] In one exemplary embodiment, NAND chip graphene heat dissipation armor technology is used in SSD samples.
[0079] Although the embodiments disclosed in this application are as above, the contents described are only embodiments adopted to facilitate understanding of this application and are not intended to limit this application. Any technician in the field to which this application belongs can make any modifications and changes in the form and details of implementation without departing from the spirit and scope disclosed in this application, but the scope of patent protection of this application shall still be based on the scope defined in the attached claims.
Claims
1. A method for obtaining the mean time between failures of a solid state drive, characterized in that: include: Determine the test conditions using the accelerated life test model based on the test objectives; Run SSD samples under defined test conditions to estimate their mean time between failures.
2. The method according to claim 1, wherein: The accelerated life test model includes an Arrhenius model.
3. The method according to claim 1, wherein: The test targets include: temperature and load.
4. The method according to claim 1, wherein: The test conditions include: temperature, sample quantity, and test duration.
5. The method according to claim 2, wherein: The Arrhenius model is used to determine the test conditions for achieving the test target; the Arrhenius model is: Where AF is the acceleration factor, which is used to convert the test results under high temperature into the predicted results under normal temperature conditions; E a represents activation energy, which represents the sensitivity of temperature to failure rate; k represents the Boltzmann constant; T1 and T2 represent the absolute temperatures at room temperature and accelerated test temperature, respectively.
6. The method according to claim 5, wherein: The accelerated test temperature is 55°C, 60°C or 70°C.
7. The method according to any one of claims 1 to 6, wherein: Run the SSD sample to estimate its MTBF: Run the SSD sample in a normal environment and an accelerated environment respectively, and record the time when each failure occurs; Record the failure time of each SSD sample and calculate the working time of the device; The collected failure data are statistically analyzed to calculate the value of the mean time between failures.
8. The method according to claim 1, wherein: The NAND patch graphene heat dissipation armor technology is used in the SSD sample to improve the heat dissipation capability.
9. A computer-readable storage medium storing computer-executable instructions, wherein the computer-executable instructions are used to execute the method for obtaining the mean time between failures of a solid-state drive according to any one of claims 1 to 8.
10. A computer device comprising a memory and a processor, wherein: The memory stores the following instructions executable by the processor: used to execute the steps of the method for obtaining the mean time between failures of a solid state drive as described in any one of claims 1-8.
11. A device for obtaining the mean time between failures of a solid state drive, characterized in that: include: Determine the module and test the module; among them, A determination module, used to determine the test conditions using an accelerated life test model according to the test objectives; A test module for running SSD samples under certain test conditions to estimate their mean time between failures.
12. The device according to claim 11, wherein The accelerated life test model includes: Arrhenius model.
13. The device according to claim 12, wherein: The accelerated test temperature T2 in the Arrhenius model includes 55°C, 60°C or 70°C.
14. The device according to any one of claims 11 to 13, wherein: The NAND chip graphene heat dissipation armor technology is used in the SSD sample.