"There is only 100.0% of life left in this SSD disk."

[rei 0]

SMART on my Samsung SSD drive is showing me a bizarre stat for Wear Leveling Count, which is currently at1% or 0.4%, depending on which number you look at. It says "There is only 100.0% of life left in this SSD disk," which clearly doesn't make sense.

SSD Life is at 99%, with 57.2TB lifetime writes.

Should I be concerned? Is this a bug?

[Jaga 61]

Sounds like a language snafu, where the word 'only' should be removed for clarity.  What does Samsung Magician say about the drive?

[rei 0]

Looks like it's in OK shape.

I'm seeing Wear Leveling Count is represented here as an integer as opposed to a percentage, whereas Scanner represents it as a percentage. Could be a case of Scanner misinterpreting the number, hence the non-sensical "only 100% of life."

Thanks, Jaga.

[Jaga 61]

The way I understand Wear Leveling Count to work, is that it starts at 0 for a brand new drive, and counts up towards some estimated lifetime maximum.  It is different for different SSDs due to manufacturing and architecture.

Each Program/Erase (P/E) cycle on all blocks on the drive raises the Wear Leveling Count number by 1.  Given the endurance of the Samsung SSDs, it's expected they'll last well past a count of 100.  The EVOs aren't as strong as the PROs, but they're still great compared against the rest of the industry.

[rei 0]

That makes sense.

So at the same time, SSD Life probably shouldn't say "Life Used" so much as it should say "Life remaining" or something.

[Jaga 61]

Actually, looking harder at your screens tells me something totally different.  Your drive's rated "raw endurance" as stated from Samsung is 500 TiB.  The P/E cycle count maximum is rated at 2,000.  

So, 2000 * 0.25 (TB in drive size) = 500 TB total P/E endurance for your drive.  Since you've only written ~57.2 TB, you should still have around 91% drive lifetime left.  I have no idea where the 100% or single wear level count figure are coming into it.  The stats appear to be completely wrong, according to what Samsung Magician is saying.

Additionally, the fact that the drive only has 2GB free space is very worrisome on a SSD.  You never want a SSD to get really full, since that puts stress on certain NAND cells when they get written/erased/re-written.  It appears you do have over-provisioning set which will help (you should get into that portion of Magician and look to be sure).  BUT - I'd recommend clearing up at least another 5-10% of that drive's space immediately, and then running a TRIM to help preserve it's lifespan.  If it has been that full for a long time, it will abnormally degrade the overall lifespan of the drive.

 

[rei 0]

Does the degradation happen regardless of whether or not you're adding more writes?

This is actually a drive that I've been using as a secondary since I upgraded to a 500gb, and its content hasn't changed much in several months.

[Jaga 61]

Nope, degradation is reliant on re-writing cells.  i.e. each Program/Erase cycle on a cell degrades it further.  If the content hasn't changed much at all, then the degradation isn't happening further.  It's good that isn't a system drive, being that full.

[rei 0]

Cool, good to know.

Thanks for the help!

[Christopher (Drashna) 623]

To be clear, SSDs are a beast.  Most manufacturers use proprietary values here, so we have to interpret those values into the "correct" meanings.  

 

If you submit to BitFlock and post the ID, we can take a look. Though I think that Alex (the Lead Developer) is going through BitFlock to add these interpretations. 

[rei 0]

1 hour ago, Christopher (Drashna) said:

To be clear, SSDs are a beast.  Most manufacturers use proprietary values here, so we have to interpret those values into the "correct" meanings.  

 

If you submit to BitFlock and post the ID, we can take a look. Though I think that Alex (the Lead Developer) is going through BitFlock to add these interpretations. 

ID: UVRPH3ZV

I appreciate the work StableBit does. I imagine there's a lot of labor that goes into software like this.

[Christopher (Drashna) 623]

Thanks.

 

And yeah, there is a lot of work behind the scenes. Especially for the SMART data! (SSDs .... are a nightmare, because each company has their own SMART standard for the SSDs) 

https://stablebit.com/Admin/IssueAnalysis/27870

[Christopher (Drashna) 623]

This should be fixed in the release version.