A scary note about Samsung enterprise SSDs

[Patrick]

I just saw this footnote in an appendix to an Intel SSD briefing during the Broadwell press workshop earlier this year:

PLI. Source –Intel. Intel® Datacenter Drives provide robust Power Loss Imminent (PLI) circuitry that helps to protect inflight data in the event of power loss. Intel drives monitor the health of the PLI circuitry via a Self Cap Test using SMART attributes. Samsung PM853T and SM843T drives were checked for capabilities and flags. No PLI monitoring capabilities (e.g. SMART Attributes) were listed in the Samsung drive specification sheet. Additionally, the drives were tested by powering off a drive and removing one electrolytic (or any other type) capacitor. The drives were then powered up to recollect SMART attribute data to determine is the cap test detected the removal of the capacitor. The Samsung drives did not detect capacitor removal.

There is not too much data in terms of exactly which capacitors were removed during Intel's testing and those are now older drives. I did not see this posted anywhere. That is the test I believe Intel mentions here.

 

[markpower28]

I wonder if that's why note7 keep blow up. lol

 

[keybored]

So, theoretically, Samsung SSDs should outlast Intel SSDs since they will continue to function even after the caps have failed. Yes, you're more likely to lose data if power is lost but how frequently does that actually happen, unless you're Delta Airlines, of course? External power would have to go bad, the backup power, and one of the caps would have to be defective in order for something to go wrong. Depending on what sort of data you're handling, those may not be bad odds at all...

 

[Patrick]

@keybored I think the point is not about the cap going bad. Intel is pointing out that the Samsung drives were not detecting a physical component being removed.

 

[zhoulander]

Don't see why this is relevant. It lacks the smart attributes and thus lacks sensing for cap removal. Hard to fault them for something that probably was never advertised. Seems more like marketing FUD to me.

 

[keybored]

@Patrick Right, but if I'm reading that verbiage correctly, Intel drives would not be able to detect a missing component either if it wasn't part of the PLI circuitry and if it had no other critical function to the drive; e.g., the controller, RAM, NAND, etc.
The point I was trying to make is that if I have two drives, both of which have PLI circuitry, but one of them does not have a monitor for this circuitry and is therefore incapable of detecting when this circuitry becomes bad due to either a cap going bad or someone removing a cap, then this does not necessarily create a scary situation. It just means that power loss protection won't work on some drives where caps failed either due to age or factory defects. And even then, this would only matter if primary and backup power both failed.

 

[aero]

@Patrick Right, but if I'm reading that verbiage correctly, Intel drives would not be able to detect a missing component either if it wasn't part of the PLI circuitry and if it had no other critical function to the drive; e.g., the controller, RAM, NAND, etc.
The point I was trying to make is that if I have two drives, both of which have PLI circuitry, but one of them does not have a monitor for this circuitry and is therefore incapable of detecting when this circuitry becomes bad due to either a cap going bad or someone removing a cap, then this does not necessarily create a scary situation. It just means that power loss protection won't work on some drives where caps failed either due to age or factory defects. And even then, this would only matter if primary and backup power both failed.

It's still better to know when a cap goes bad so you can replace the drive, rather than risk data loss during a power failure event, no matter how likely/unlikely it is.

 

[keybored]

It's still better to know when a cap goes bad so you can replace the drive, rather than risk data loss during a power failure event, no matter how likely/unlikely it is.

Sure, and I'm not questioning that it's better. But does this automatically make all the existing drives that were built without such monitors scary? I don't think so. Not all use cases require such reliability.

 

[fractal]

@keybored I think the point is not about the cap going bad. Intel is pointing out that the Samsung drives were not detecting a physical component being removed.

I am not sure why this is an issue. I worked on my own cars for years when I was younger. I often had pieces left over when I was done putting things back together. The car still ran. I kept the leftover bits in a coffee can and it is strange how the quantity of stuff in that can rarely changed but the exact contents did after working on the beast.

All joking aside, adding extra circuitry to detect a failed (or removed) component is of value if that component is likely to fail. Electrolytic capacitors are notorious for short lifespans under adverse conditions so they may very well get tired before the end of the drives service life. If so, knowing that the storage capacitor is failing, or has been removed, is of value. Otherwise the whole thing could very well be a marketing gimic.

 

[Fritz]

Think I read somewhere about Intel CPU's having missing caps and still working normally so I guess some caps are important and some aren't.