Solved Crystal Disk Info questions about Health Status

SSDs get “Good” “99%” for example

My HDD gets “Good”
but no % > Why?
Crystal Disk Info reports “Caution” if it detects the raw value over the threshold value (Health Status Setting) > what does the following screenshot say about my HDD?
[05] [C5] [C6] are as in the screenshot, [FF] Life is not listed at all, is that a cause for concern?

Part of the problem with interpreting S.M.A.R.T table data is that different manufacturers will expose different values to be read from disk to disk revision and from firmware to firmware revision. For example here is the table from one of my Sandisk SSDs:


As you can see I have different identifiers for categories than you and even the category names are not the same, 'Reallocated Sectors Count' vs 'Reassigned Block Count', there is no C6 entry at all, or it is not exposed.

Then there is interpreting the actual results listed for each category, you can change to decimal view in the Theme, Advanced menu.
Take the Available reserve space value 100, 100, 4, 100 so this means what? Current and worst both 100 so static, threashold is 4, does that mean when the count, in 'Raw Values', gets down to 4 it is time to swap out the disk? And what is the value of 4, is it 4%, 4GB, 4 Blocks......

The entry for Maximum Bad Blocks per die, according to my results the threshold has been exceeded by 28, 28 what? And is that per die or only one die? But the disk reports as good condition, 99% life left.
My NVME drives show even less items on the table with again different terms and value identifiers.

S.M.A.R.T data is only a very rough guess at the condition of a disk as it is inialised by the BIOS at startup, in an effort to predict failure, as an early warning system it might show results you can interpret as impending doom (basically if things like uncorrectable sectors is high and grows rapidly) but a disk can fail for many other reasons, not all of which are exposed in the table as readable values.

If the app, and other apps, don't just rely on one, says the disk is in good condition, caution or dying then that is a result of the app creator interpreting the values they chose to read and are available to read to determine the disk's health, nothing more.

The % figure for SSDs is how much you have of the nominal vendor writes left. The nominal figure is the minimum number of writes a vendor guarantees the drive will have. In reality, you will get a lot more - the low figure is a scam really to avoid warranty payouts. The % use is pretty meaningless really.

HDD vendors do not provide any nominal figure for number of writes, so you cannot estimate a percentage.

Thanks for the comments, folks! I think, I just want to know what 'good' means for my HDD. It's 8 years old, still silent, nor are there any other aging symptoms.

Can I trust that the W10 OS gives me, say 1 week notice to buy a replacement SSD?

I sense a 'no guarantees in life' reaction, but what are the odds?

SSDs tend to suddenly go read only when the firmware detects an unaceptable number of block erase/ write errors/ retry operations based on the manufacturers determination and the NAND producers estimates. Although a catastrophic controller failure can cause the SSD to not be accessable at all.
The most obvious sign might be an extreme slowdown of the SSD even though there is plenty of free space, but this can be due to Windows (Explorer) issues as well.
Traditional HHDs will typically give advanced warnings, trouble reading/ writing, excessive noise etc.
There are no guarantees as you said, any hardware can suddenly fail with no warning.
The S.M.A.R.T values can be taken as a rough guide to the health of the SSD/ HDD.

Haydon said:

Thanks for the comments, folks! I think, I just want to know what 'good' means for my HDD. It's 8 years old, still silent, nor are there any other aging symptoms.

Can I trust that the W10 OS gives me, say 1 week notice to buy a replacement SSD?

I sense a 'no guarantees in life' reaction, but what are the odds?

Click to expand...

Even if you got to zero on percent of guaranteed life left, it does not mean the drive will fail. In fact the parameter can % used can go up to 256% at which point it gives up counting.

All the other parameters do not help that much either. They are all related to writing efficiency, but they do not monitor interface electronics for example. In fact an SSD is more likely to fail from a hardware interface component failure rather than the drive being worn out from a writing point of view.

A hardware type of failure can happen at any time with usual statistical pattern that rate of failure increases as drive get older BUT it can happen on new devices as well (bad luck). Even new cars breakdown.

At best information will tell you condition may be deteriorating but you cannot extrapolate from that any timescale. All you can do is prepare for the day of failure in the usual way e.g. regular image backups.

Haydon said:

I think, I just want to know what 'good' means for my HDD. It's 8 years old, still silent, nor are there any other aging symptoms.

Can I trust that the W10 OS gives me, say 1 week notice to buy a replacement SSD?

I sense a 'no guarantees in life' reaction, but what are the odds?

Click to expand...

For an HDD 'good' means none of the indicators for potential failure are present, in particular the raw values for Reallocated Sector Count and Pending Sector Count are both zero.

There are no guarantees of course, but HDD troubles usually start off gradually. When Reallocated Sector Count starts to grow it's a good time for a replacement SSD, you usually have enough time to get your data off the HDD before it fails. I've had to do that just the once.

Thanks again for the comments, folks

Looks like I shall install a phone app for measuring dB loudness of my HDD, just kidding!

I will mark this thread solved, no kidding!

Bree said:

For an HDD 'good' means none of the indicators for potential failure are present, in particular the raw values for Reallocated Sector Count and Pending Sector Count are both zero.

There are no guarantees of course, but HDD troubles usually start off gradually. When Reallocated Sector Count starts to grow it's a good time for a replacement SSD, you usually have enough time to get your data off the HDD before it fails. I've had to do that just the once.

Click to expand...

Do you mean replacement HDD or do you mean a replacement drive and recommend an SSD?

What I meant and Bree quoted was what I paid for the HDD 8 years ago will nowadays get me an SSD

cereberus said:

Do you mean replacement HDD or do you mean a replacement drive and recommend an SSD?

Click to expand...

I'd always recommend replacing any HDD that fails with an SSD, that's what I did when my HDD started to die.