Threshold Exceed Condition Prediction

Threshold Exceed Condition Prediction*

Introduction

DiskCheckup uses SmartDisk DLL SDK to predict the Threshold Exceed Condition (TEC) date of a device based on historical SMART attribute data. For this purpose, make sure to check "Record SMART attribute for TEC computation" in the configuration window:

DiskCheckup will record and write all the SMART attributes of all SMART devices to a binary file each time DiskCheckup is started, refreshed or the user manually clicks on a hard disk icon in the "Physical Devices" window list.

Recorded Information

The following information is recorded:

1.	Time the recording was made;

2.	Attribute ID;

3.	Current attribute value;

4.	Current attribute raw value;

5.	Current attribute worst value;

Note that threshold values are not recorded because they remain constant with time.

Threshold Exceed Condition Prediction

In the above graph, there are 6 sets of collected data, sample 0 to sample 5, represented by the red line (). The threshold value (which remains constant) is represented by the black line (). The blue line () represents the predicted threshold exceed condition date based on the 1st and last sample while the green line () represents the predicted threshold exceed condition date based on the last 2 samples. Based on the data above, the earliest predicted failure date will occur at sample 8 and the latest predicted failure date will occur at sample10.

DiskCheckup displays the earliest predicted failure date (the time when sample 8 will take place in the example above) - this being the most pessimistic guess. To successfully predict a TEC date and time for an attribute, all the following conditions need to be met:

1.	The threshold value of the attribute must not be zero;

2.	The must be a minimum of 3 sets of data;

3.	There must be a difference in the attribute value between the 1st and last set or between the last 2 sets;

If any of the above condition is not met, "N.A' will be displayed in the "Predicted TEC Date" column of the attribute.

Important Information on Failure Prediction*

DiskCheckup predicts the failure date of your hard drives based on the collected SMART attributes of your hard drives. It computes the failure date by assuming a linear degradation of the attribute values. This predicted time should be taken as a guide only and should not be considered accurate. There are many contributing factors that might cause a drive to fail, for example high ambient temperature, electrical short circuits or failure of its mechanical and electrical parts. As such, it is susceptible to sudden failures. This is why you should always backup your data on a regular basis..

*Please read our failure prediction disclaimer section.