Question Samsung SSD Failing - Help me understand SMART

[Nite01]

The following are two identical SSD working in a RAID setup (Mirror).
The one reported failing has the wear leveling count to 1, while the other one with the same amount of writes is at 47... how is it possible ?
Are there other parameters to check ? Whats the difference between the 2 ssd ?

Thanks

 

[USAFRet]

They have almost 50,000 running hours.
5.5 years of running 24/7.
30TBW

One of them is dying.
It happens.
Replace, before it actually does die.

 

[Nite01]

They have almost 50,000 running hours.
30TBW

One of them is dying.
It happens.
Replace, before it actually does die.

yeah, I know, Im the guy from the other thread, Im already in the process of reinstalling !
I felt it was odd that one of them still is at 47 while the other went to 1

 

[fzabkar]

Were the drives delivered with the existing firmware, or were they subsequently updated? If the latter, were they updated at the same time?

This particular model was affected by bad NAND, according to these Russian researchers:

https://forum.acelab.eu.com/viewtopic.php?f=227&t=8735

You ask me - are the guys from Samsung didn't know about that issue? Why they did not find the way to fix this bug?!

And I will answer - they release new FW, which make very simple thing - in background, when you working with your laptop or with PC, it just rewrite customer data again and again, again and gain by cycle, every time with the only goal - to keep the data and charges inside cells "fresh". When drive is not connected to power source, charge from cells is flowing away.

 

[mdd1963]

50K hours...; impressive! (My own 960 EVO only has 13k hours in 5 years, for comparison)

 

[USAFRet]

yeah, I know, Im the guy from the other thread, Im already in the process of reinstalling !
I felt it was odd that one of them still is at 47 while the other went to 1

They are two individual devices.
It happens.

One is near death.
The other, not quite yet.
Always have a backup. RAID 1 is not a backup.

 

[Nite01]

Were the drives delivered with the existing firmware, or were they subsequently updated? If the latter, were they updated at the same time?

This particular model was affected by bad NAND, according to these Russian researchers:

https://forum.acelab.eu.com/viewtopic.php?f=227&t=8735

Im pretty sure I never updated their firmware, also because Samsung Magician doesnt support drives in a RAID setup.

 

[USAFRet]

Im pretty sure I never updated their firmware, also because Samsung Magician doesnt support drives in a RAID setup.

Yes, there was a major issue with the original 840 EVO firmware.
I have 2 of them, 250GB.

But, firmware or not...one of them is dying.
What will you do?

 

[fzabkar]

I'm just speculating, but it may be that one or more of the NANDs has become unreliable and is being refreshed (reprogrammed) more often than the others.