35 ms·

What really happens when the level is low ? Less capacity ? Data loss ? Performance decreases ?

ddingus 8y ago
This varies by SSD. Some just fail hard and that ranges from bricking to loss of filesysten intregity. Others stop allowing writes. Still others will slow down, or lose capacity. I have had two die on me after a few years of work involving tons of writes. One cheap SSD just bricked. Gone. The Samsung I had started doing weird things with capacity. Personally, I just cycle them when I see a deal out there. Old ones do need to be powered up, from time to time just like USB thumb drives do, or the contents can be lost.
- dylan604 8y ago
  How does one know how a particular model of SSD will behave? If I had the choice, I'd rather the drive enter a read-only state rather than becoming a brick. So when I'm shopping for a new drive, how do I use this a determining factor in choosing the new drive? Is it a known thing that Vendor X will brick, Vendor Y will read-only, or Vendor X Model XXX will brick while Vendor X Model YYY will read-only? If so, where can one find this level of information on the inner workings of a drive? Most tech reports are solely focused on read/write speeds as that's what the majority of people are concerned. Inquiring minds want to know...
  - ddingus 8y ago
    Doing that as hard. With older ssds you can find reviews and other information. With new ones, I consider it a crapshoot.
  - whitexn--g28h 8y ago
    It's going to come down to the firmware and controller. That can even be different when the vendor and model are the same.
  - maxxxxx 8y ago
    "I'd rather the drive enter a read-only state rather than becoming a brick" Totally agree. However, all of the SSDs that have failed on me all got bricked. I have never seen one that went into read only mode which was disappointing.
pkaye 8y ago
I've worked on SSD firmware before. Obvious the implementations may vary but typically there is no hard failure. These are just projections based on data sheet endurance specs. What you need to look at additionally is how many defect blocks there are (another SMART spec) as it will start to rapidly increase as more and more flash blocks go bad. When the level is low, capacity shouldn't decrease as there are spare blocks. There should be no data loss expect by catastropic block failurs (some SSD have internal RAID like redundancy.) There might be a slight performance decrease as the error correction algorithms become more active.
- komali2 8y ago
  Those are firmware level error corrections? Or like, driver?
  - mey 8y ago
    SSD have their own correction and wear leveling algorithms. In this case they were referring to device firmware.
  - pkaye 8y ago
    Its in the controller. A combination of hardware and firmware. A large percent of them will be handled by the hardware but a small number requires firmware intervention.
opencl 8y ago
They generally stay fairly consistent in performance, near the end you start getting a whole lot of reallocated sectors and then it just suddenly stops working. Depending on the controller it either locks itself to read-only or becomes totally inaccessible. https://techreport.com/review/27909/the-ssd-endurance-experiment-theyre-all-dead https://techreport.com/review/27909/the-ssd-endurance-experi...

This varies by SSD. Some just fail hard and that ranges from bricking to loss of filesysten intregity. Others stop allowing writes. Still others will slow down, or lose capacity. I have had two die on me after a few years of work involving tons of writes. One cheap SSD just bricked. Gone. The Samsung I had started doing weird things with capacity. Personally, I just cycle them when I see a deal out there. Old ones do need to be powered up, from time to time just like USB thumb drives do, or the contents can be lost.

dylan604 8y ago
How does one know how a particular model of SSD will behave? If I had the choice, I'd rather the drive enter a read-only state rather than becoming a brick. So when I'm shopping for a new drive, how do I use this a determining factor in choosing the new drive? Is it a known thing that Vendor X will brick, Vendor Y will read-only, or Vendor X Model XXX will brick while Vendor X Model YYY will read-only? If so, where can one find this level of information on the inner workings of a drive? Most tech reports are solely focused on read/write speeds as that's what the majority of people are concerned. Inquiring minds want to know...
- ddingus 8y ago
  Doing that as hard. With older ssds you can find reviews and other information. With new ones, I consider it a crapshoot.
- whitexn--g28h 8y ago
  It's going to come down to the firmware and controller. That can even be different when the vendor and model are the same.
- maxxxxx 8y ago
  "I'd rather the drive enter a read-only state rather than becoming a brick" Totally agree. However, all of the SSDs that have failed on me all got bricked. I have never seen one that went into read only mode which was disappointing.

pkaye 8y ago

I've worked on SSD firmware before. Obvious the implementations may vary but typically there is no hard failure. These are just projections based on data sheet endurance specs. What you need to look at additionally is how many defect blocks there are (another SMART spec) as it will start to rapidly increase as more and more flash blocks go bad. When the level is low, capacity shouldn't decrease as there are spare blocks. There should be no data loss expect by catastropic block failurs (some SSD have internal RAID like redundancy.) There might be a slight performance decrease as the error correction algorithms become more active.

komali2 8y ago
Those are firmware level error corrections? Or like, driver?
- mey 8y ago
  SSD have their own correction and wear leveling algorithms. In this case they were referring to device firmware.
- pkaye 8y ago
  Its in the controller. A combination of hardware and firmware. A large percent of them will be handled by the hardware but a small number requires firmware intervention.

opencl 8y ago

They generally stay fairly consistent in performance, near the end you start getting a whole lot of reallocated sectors and then it just suddenly stops working. Depending on the controller it either locks itself to read-only or becomes totally inaccessible. https://techreport.com/review/27909/the-ssd-endurance-experiment-theyre-all-dead https://techreport.com/review/27909/the-ssd-endurance-experi...