Endurance experiment kills six consumer SSDs over 18 months
techreport.com
techreport.com
I am NOT impressed with the behavior at end of life. In fact it makes it wary of using any SSD.
A bad SSD should go read only, and stay that way. Not self-brick, and make the data unrecoverable.
Of course, there are other solutions to this problem: sledgehammer, etc
And you could allow secure erase while still prohibiting normal writes. The cells aren't actually gone or unusable after all, just unreliable. A secure erase would work fine on them.
No, because they do this http://vxlabs.com/2012/12/22/ssds-with-usable-built-in-hardw...
Erase the AES key -> data is gone
"Read only" after some fixed number of writes would be safer. But then the complaints would be "why can't they just allow me to write as much as I can, I have the backup somewhere anyway." Which is also a valid wish. So it would be the best to be able if user could select the mode.
By doing that, that area will easily outlast the regular flash.
Also hope you never have a power outage or hard reset of any kind.
And as for power outages and hard resets, there's these nifty things known as capacitors. It only needs to last as long as is necessary to write the data to flash.
How is that different from any other write the drive had experienced though?
I can easily see someone having their computer lock up / etc, restarting, and losing their data. As restarting is often one of the first debugging steps for so many things.
"If your SSD has stopped working and you cannot access the data, the best thing to do is to turn it off to prevent further damage." [1]
Maybe that advice needs to be reconsidered?
[1] http://www.payam.com.au/content_common/pg-ssd-data-recovery....
If you're the kind of person who can troubleshoot a faulty drive, then you're not the kind of person who should reboot as a first step towards debugging. Especially if you suspect a faulty drive.
Intel died after power cycle because of buggy Sandforce chip/firmware. Intel bullshit fairytale was post facto rationalization. There is NO UNIVERSE where bricking user product full of data is a good thing, especially if you promised read only failure mode in the documentation.
Without that the damage would have been piecemeal as sectors went bad, rather than watching a chip go poof and lose access to everything.
Plan for the worst, hope for the best.
In fact my personal advice is to plan to lose everything since your last backup. If you can't afford that risk, back up more often.
No disk technology is perfect nor instantly comparable. I consider this to be purely a 'value for money before it blows up' assessment. The results make me happy as I've been recommending and use 840 pros for a while now.
That's one of the things I look for in a hard disk - how does it act when it fails. A "good" failure is some bad sectors, but otherwise OK.
One of the SSDs died a couple of weeks ago (unexpectedly Linux didn't fail safe properly, it fell over trying to read from the broken one and didn't seem to try read from the other instead, upon coming back up it ran from the good drive OK) and RAID saved my much hassle rebuilding from the previous night's backups.
The SSDs in my desktop box aren't RAIDed, nor in my laptop (two wouldn't fit), but I can easily survive either of those being out of action for a couple of days and may backup regime involving copies on the local file server and on remote hosts (fingers crossed) should mean nothing gets lost if they do die.
I've not found the failer rates of SSDs to be any different to spinning media - I don't trust important data to a single drive of either type.
http://www.samsung.com/global/business/semiconductor/minisit...
>With twice the endurance of the previous model, the 850 PRO will keep working as long as you do. Samsung's V-NAND technology is built to handle 300 Terabytes Written (TBW)* which equates to a 40 GB daily read/write workload over a 10-year period. Plus, it comes with the industry's top-level ten-year limited warranty. * 840 PRO: 73 TBW < 850 PRO: 150 TBW 850 PRO 120/250 GB : 150 TBW, 500/1TB(1,024 GB) : 300 TBW
Of course an average consumer can't produce that. A lot of the data I write to any medium at home is never overwritten. But not every use is the use of an average consumer, knowing the actual limits is important.
(Also, drive writes per day and GB per day are the same metric.)
they ALL are, every single SSD has this magical pulled out of the ass ~70TB number. And dont expect it to go up any time soon, every new generation of flash has fewer write cycles, this cancels out any gains you might have from greater capacity.
http://techreport.com/review/27909/the-ssd-endurance-experim...
I feel a lot better about that production hardware now that I have seen first hand what SMART reports as the drive is running out of reallocation sectors.
I hope to find some benchmarks like this on enterprise level stuff to fight the bullshit around SSDs not being capable of write intensive operations.
the difference is number of writes an individual flash cell can take. Consumer - multi-level cell (MLC) - 1000-3000 writes (thus 240GB disks start to fail around 600-700TB written) where is enterprise SSD flash - single-level cell (SLC) - up to 100000 writes.
Very proud to exclusively use 840 Pro SSDs in my towers.
It looks like they ran the test for 18 months.
The low number of reallocated sectors suggests that the NAND deserves much of the credit. Like all semiconductors, flash memory chips produced by the same process—and even cut from the same wafer—can have slightly different characteristics. Just like some CPUs are particularly comfortable at higher clock speeds and voltages, some NAND is especially resistant to write-induced wear.
The second HyperX got lucky, in other words.
So it's definitely possible that the 840 Pro has reliability problems even though one of them won this test.
Even if you don't know that, basic stats should tell you that testing a single unit from each manufacturer is going to be meaningless at best, misleading at worst.
Is less expensive than testing a dozen drives of each model, and better than testing no drives at all. It's not meaningless at all; it just has to be read with the right caveats.
840 and 840 Pro are not the same drives.