According to my SSD SMART information, "Percentage lifetime used: 90%."

Does it mean the SSD's remaining lifetime is estimated to be 10% or 90% of its entire lifetime?

enter image description here

  • SMART attribute "CA" is 202, Data address mark errors according to cropel.com/library/smart-attribute-list.aspx. Seems like you want "E9" which is Media Wearout Indicator, Remaining flash memory life (on an SSD). What is the power-on (hours) number? – sawdust Nov 24 '19 at 23:19
  • @sawdust The power-on (hours) number on the screenshot is 16993 hours, and that's what I see in the value for 09, which is the corresponding SMART attribute for power-on hours. The attribute E9 isn't displayed in CrystalDiskInfo for that disk. I agree that your link seems to disagree with CrystalDiskInfo regarding the meaning of CA. – Franck Dernoncourt Nov 24 '19 at 23:28
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    After more research I've decided to delete my original answer and post a new one. Your drive should be fine! – MMM Nov 24 '19 at 23:56
  • @Moab the attribute name says "percent" – Franck Dernoncourt Nov 25 '19 at 15:03

It means your drive has 90% "life" left.

After some additional research, I came across this Crucial.com article that mentions the following:

In regards to the attribute named “Percentage Lifetime Used” (sometimes referred to as “Percent Lifetime Remaining”), this is simply a metric for how much wear life is left on your SSD. A solid state drive, like any flash memory-based storage device, has a limited amount of data which can be written to the memory blocks before they start to lose their reliability, and eventually go into read only mode. Your Crucial SSD will keep track of this life with SMART attribute 173, “Average Block Erase Count.” The Lifetime Used is a reflection of the block erase count in terms of a percentage. For example if your drive is rated for 3000 block erases and you have a total of 100, your Percentage Lifetime Used would be 100/3000, or 3-4%. For percent lifetime remaining we would simply take (3000-100)/3000 = 96-97%. These attributes are not a full picture of the health of a drive, but an expectation of how much usable life is left.

Because the attribute is vendor-defined, it can be complicated and confusing to figure out how each drive implements it.

Try running the Crucial Storage Executive tool to get a more accurate SMART reading that (should) follow Crucial's definitions by the book.

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    the quote you used directly contradicts your claim. I interpret it exactly the opposite and the math they demonstrate seems to prove it. Percentage Lifetime Used is how much is used, not how much is remaining, which is exactly what your quote calls “percent lifetime remaining” and is clearly the opposite of “percentage lifetime used.” Your emphasis on how much wear life is left, doesn’t mean anything other than that. It could be life used or life remaining, both would tell you “how much wear life is left.” – Appleoddity Nov 25 '19 at 5:40
  • But, I do agree that the crucial tool should be used as the final say because these smart codes are completely vendor dependent. – Appleoddity Nov 25 '19 at 5:55
  • @Appleoddity I thought so too at first but then I found other results on the net that say that it's time left instead of used - SMART is confusing like that, especially with vendor defined attributes like this. – MMM Nov 25 '19 at 7:23
  • @Appleoddity note the raw value listed by CrystalDiskInfo, it's 10. Since CDI's health value is the same as the "humanized" value I think it's save to say that the drive is still healthy. Even so OP should run Crucial's own tool and see what that says – MMM Nov 25 '19 at 7:35
  • Apparently Crucial agreed this quote was dumb, as it's not there anymore. They are very clear now. 202, or Percent Lifetime Used, is just that: USED. Not LEFT. USED. CrystalDiskInfo likely calculates remaining from that. – Fmstrat May 10 at 23:47

Turns out that the screenshot I had included in the question was a bit old. A more recent version of the screenshot shows that the "Percent Lifetime Used" is now down to 84%, which corroborates MMM's most recent answer stating that Percentage Lifetime Used” = how much wear life is left on your SSD (higher is better):

enter image description here


Use the diagnostic software that came with your drive..I use them and a payware program named Hard Disk Sentinel on all my WD SSD 500mb-1TB Drives in my rigs. Anyway 90% or what ever % means HOW MUCH LIFE YOU HAVE LEFT.

I don't use my SSD's for gaming or storage only for OS's and productivity software like Security,Diagnostic, Tool or business type software NO games or media etc. For example one of my drives after 4 years of use now has 97% life expectancy so you must you your drive as either a main drive or for games or something like storage or server use that constantly writes to the disk in big chunks. Writing to an SSD is what wears it out.

Use a real app or payware program that is more accurate not these lame free ones like Crystal etc that ONLY show SMART a good program shows every single parameter not just SMART.

Or use the one that came with your drive its usually the most accurate as its made for the exact drive you own. No offense but how could you ever think it was the other way round? 90% used? LOL! That would be impossible unless you write TB's of data a day or your drive is broken.

In any case SSD's are common or the norm today and their cheap to boot so when it gets close to the end just buy another one or a bunch of em I always a have a few SSD's as backups in storage just in case etc. Again the percentage is ALWAYS just the life left nothing more its why they all say GOOD. You be concerned when they say BAD. Just think of it as a fuel gauge when it hits 10-5% time to buy or use a new one. : )

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