Health indicator goes down then up

[Virgil]

I got a report from Hard Disk Sentinal about my laptop's disk showing among other information the following:

Physical Disk Information - Disk: #0: KBG30ZMS256G NVMe TOSHIBA
Hard Disk Summary

Hard Disk Number : 0
Interface : NVMe
Disk Controller : Intel(R) Chipset SATA/PCIe RST Premium Controller (RAID) [VEN: 8086, DEV: 282A] Version: 17.9.6.1019, 2-2-2021
Disk Location : Bus Number 3, Target Id 0, LUN 0
Hard Disk Model ID : KBG30ZMS256G NVMe TOSHIBA
Firmware Revision : ADDA0103
Hard Disk Serial Number : 98NPA3DSPWFP
Total Size : 244191 MB
Power State : Active
Device Type : Fixed Disk
Logical Drive(s) : C: []
Current Temperature : 41 °C
Maximum Temperature (Ever Measured) : 83 °C, 6/25/2023 7:20:10 PM
Minimum Temperature (Ever Measured) : 25 °C, 1/24/2023 12:07:02 PM
Power On Time : 406 days, 3 hours
Estimated Remaining Lifetime : 527 days
Lifetime Writes : 62.57 TB

Health :

61 % (Fair)
Performance :

100 % (Excellent)

The status of the solid state disk is PERFECT. Problematic or weak sectors were not found.
The health is determined by SSD specific S.M.A.R.T. attribute(s): Available Spare (Percent), Percentage Used
The TRIM feature of the SSD is supported and enabled for optimal performance.

It is recommended to continuously monitor the hard disk status.

A couple of days ago a similar report showed the following:

Physical Disk Information - Disk: #0: KBG30ZMS256G NVMe TOSHIBA
Hard Disk Summary

Hard Disk Number : 0
Interface : NVMe
Disk Controller : Intel(R) Chipset SATA/PCIe RST Premium Controller (RAID) [VEN: 8086, DEV: 282A] Version: 17.9.6.1019, 2-2-2021
Disk Location : Bus Number 3, Target Id 0, LUN 0
Hard Disk Model ID : KBG30ZMS256G NVMe TOSHIBA
Firmware Revision : ADDA0103
Hard Disk Serial Number : 98NPA3DSPWFP
Total Size : 244191 MB
Power State : Active
Device Type : Fixed Disk
Logical Drive(s) : C: []
Current Temperature : 83 °C (Overheat)
Maximum Temperature (Ever Measured) : 83 °C, 6/25/2023 7:20:10 PM
Minimum Temperature (Ever Measured) : 25 °C, 1/24/2023 12:07:02 PM
Power On Time : 405 days, 19 hours
Estimated Remaining Lifetime : 354 days
Lifetime Writes : 62.53 TB

Health :

50 % (Fair)
Performance :

100 % (Excellent)

The following error(s) detected:
Temperature is above the over-temperature threshold / below the under-temperature threshold.
The health is determined by SSD specific S.M.A.R.T. attribute(s): Available Spare (Percent), Percentage Used
The TRIM feature of the SSD is supported and enabled for optimal performance.

It is recommended to continuously monitor the hard disk status.

My question is how did the "Health" indicator change from 50% back to 61%? I admit that I became worried when it had dropped to 50%, but now I'm even more worried because it went back up to 61%! It doesn't seem to be a reliable indicator to me.

[hdsentinel]

Please review the text description, designed exactly to explain the situation, what factor(s) may affect the Health %.

When the lower Health % reported, the text description clearly shows that

The following error(s) detected:
Temperature is above the over-temperature threshold / below the under-temperature threshold.

There can be some situations when temporary issues can affect the Health % exactly as you can see: when the internal temperature-alert mechanism of the SSD activated (when you may notice slower performance too due to temperature throttling).

It is a warning sign that the SSD is having problems in its general operation and long term similar use may even cause malfunction/failure.

The Health % designed exactly to reveal and show temporary issues too - exactly to increase attention to these problems which may reduce the lifetime of the SSD. Moreover, the Health % graph on the bottom designed to show the daily lowest Health % (even if the Health % then increases back) exactly to suggest that there may be something to do (maybe improve cooling if possible in this case).


> It doesn't seem to be a reliable indicator to me.

Sorry, I do not really understand.
The disk Health % is the only reliable indicator: exactly as you can see, it designed to show not only problems which can directly affect the operation (bad sectors, wearout, degradation, etc...) but also report when the SSD triggers an internal alert like this one. The Health % designed exactly to increase attention - and (as we can see) it does its job exactly as expected.

[Virgil]

Thank you for the thorough explanation about the meaning of the Health indicator. Temperature spikes on my laptop are a very regular phenomenon. In fact I became so used to them that I don't pay much attention anymore. What was different this time was the drop in Health from 61% to 50% which was quite large compared to the gradual drop that I have been seeing over the last four years. The drop to date has been by 1% every few weeks which I took to be a normal pattern.

I was planning to replace the disk once the Health indicator would slowly reach 50%. However, given this sudden fall even though it has returned to the most recent level, I'm going to replace it immediately.