If an Intel SSD is disconnected and sits on a shelf for 1 yr.

Happy Hopping

Happy Hopping

Supreme [H]ardness
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w/ no electricity connects to it, would the files inside still be intact?

Is there any reason to believe the files won't be intact if it continues to sit on a shelf w/ no electricity connects to it
 
Just having it powered up won't even keep the data refreshed, it's not DRAM where it periotically gets recharged, if it's just sitting there in a read only mode for a year even with power it will still degrade, data would need to be actively re-written to refresh the cell charge, same with hard drives. That's why RAID cards have a scrubbing option, any data that degrades is periodically checked and refreshed with parity or data from other drives.
 
-Dragon- said:
Just having it powered up won't even keep the data refreshed, it's not DRAM where it periotically gets recharged, if it's just sitting there in a read only mode for a year even with power it will still degrade, data would need to be actively re-written to refresh the cell charge, same with hard drives. That's why RAID cards have a scrubbing option, any data that degrades is periodically checked and refreshed with parity or data from other drives.
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what software does that?
 
We have some SLC 32GB X-25'Es (We ran them from Oct 2008-Mar 2011) that we made acrylic paperweights out of and had a few left over. These haven't been powered on since ~Mar 2011 and after we nuked them we wrote 32GB of porn to the drives. Powered up and played fine today.
 
jrocks84 said:
I believe the length of time is 5 years, but I'm not certain.
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It's longer or shorter depending upon the lithography process size used for the NAND flash ROM chips. The smaller the process size, the less time data will survive un-powered.

The problem is caused by the ability of electrons to "quantum tunnel" over very short distances, regardless of any material that happens to be in the way. As process sizes get smaller and smaller, the distance between individual bits shrinks, making it ever-easier for an electron to tunnel out.

You might already see the problem here; drive manufacturers are pushing for smaller process sizes because it makes drives cheaper to produce. The smaller they shrink this stuff, the more quickly data can evaporate off of it.

This isn't a linear regression, either. The likelihood that an electron will tunnel through a material increases exponentially as the thickness of that material decreases linearly. Basically, halving the process size results in your data lasting far less less than half as long. I imagine we will have come up with a suitable replacement for Flash before this happens, but I've heard some estimates that flash ROM produced on a process size below 6nm would result in your data evaporating in mere minutes :eek:
 
First of all, thanks for that link. For a technology that I paid 5X the price of a hard drive, this is so screw.

Anyhoo, is there a way to know if there is data retention problem?
 
The reason to buy an SSD is for performance first, and resistance to shocks second. If you don't need either but want something else, don't buy an SSD.
 
-Dragon- said:
Just having it powered up won't even keep the data refreshed, it's not DRAM where it periotically gets recharged, if it's just sitting there in a read only mode for a year even with power it will still degrade, data would need to be actively re-written to refresh the cell charge, same with hard drives. That's why RAID cards have a scrubbing option, any data that degrades is periodically checked and refreshed with parity or data from other drives.
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NAND flash needs to be "refreshed" over a period of time based on its lithography. True you cannot just keep them powered up, but the SSD controller is responsible to "scrub" the flash meaning it is going to read the data in the cells and write them back out to new locations. This is the same process used to move valid data during garbage collection. Since this process is built into the FW of the SSD controller, you only need to keep power to the SSD as a whole and the controller will do the work internally to the SSD. No external SW required.

Most MLC flash used in SSDs today has retention period of 1 year when it is near its end of life (consumed all of its program/erase cycles). When you first start using it the retention period is more like 10 years. Either way, flash is not a good long term shelf storage medium, but who would do that at current costs?
 
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