SSDs lose data if left without power

Post by **FlyingPenguin** » Sun May 10, 2015 7:46 pm

The actual title is link bait: "SSDs lose data if left without power for just 7 days".

That was a worst case, and obviously a defective drive, but as the article mentions, the manufacturers do indicate on the specs for SSDs that the data does deteriorate over time: a few months for enterprise class drives, and couple of years for consumer class drives.

It's also made worse if the drives are stored in a warm place.

So, cut to the chase: don't use an SSD for archiving.

http://www.ibtimes.co.uk/ssds-lose-data ... ys-1500402

normalicy · Post by **normalicy** » Mon May 11, 2015 3:51 am

Jeez, that's worse than I would have expected. I guess this also means that they aren't good for occasional use PCs.

Post by **FlyingPenguin** » Mon May 11, 2015 7:23 am

Define occasional use. I have a car laptop with an SSD in it. It almost never gets used, and it sits in a warm car all day. No issues so far.

We're talking years for consumer drives. This would also be a gradual process.

Losbot · Post by **Losbot** » Mon May 11, 2015 9:11 am

I believe they found that pics & porn deteriorate first, so keep them puppies powered on.

EvilHorace · Post by **EvilHorace** » Mon May 11, 2015 10:07 am

But all ipods, ipads, cell phones have SSDs and can sit unused for long periods of time w/o problems.

Post by **FlyingPenguin** » Mon May 11, 2015 10:42 am

Evil: iPads, phones, etc do NOT have SSD drives. They use NAND memory, like SSDs do, but it's a much slower and lower density NAND more like the type used in USB Flash drives and memory sticks. They also don't have the sophisticated controllers that SSDs have.

The NAND technology in SSDs is VERY bleeding edge, but as such it's not as robust.

Post by **FlyingPenguin** » Mon May 11, 2015 11:28 am

Also let me point out that Phones and iPads are never powered off -they just go to sleep. NAND memory only discharges when powered off.

ANY NAND memory will lose it's memory over time. I have no idea what the rated data retention life of a flash drive is, but it should be a heck if a lot longer than an SSD. I personally have had flash drives sit around for 10 years that are still readable.

That said, we haven't had flash drives long enough to know how long data will last. SSDs are worse because they are so high density. Flash drives don't need fancy controllers because they are low enough density not to require any major wear leveling or error correction. SSDs need sophisticated controllers that can do all that because they are error correcting all the time on the fly. BTW: When an SSD dies completely so that it's unmountable, that's usually a failure of the controller chip, not the memory.

Spinning hard drives are cheap as heck, and a spinning hard drive sitting unpowered in a safe deposit box will be readable for a couple of decades (assuming the interface is still in use - and yes until recently I had a couple of old IDE drives in my safe deposit box, and I can still read them using an IDE to USB adapter). I use old drives that I no longer trust as boot drives, but pass a Spinrite 4 scan with no errors, as data archive drives. I have dozens of drives in my safe deposit box. Every once in a while I just image the whole file server to a drive and toss it in there, in addition to my other regular scheduled backups.

All video studios and TV stations & networks now use hard drives for long-term storage, using storage systems like the one shown below. This is why spinning drives aren't going away any time soon. SSDs are great as boot drives, but you still want your long-term data stored on spinning drives, until they come out with some kind of archival holographic storage system.

Losbot · Post by **Losbot** » Mon May 11, 2015 1:50 pm

They got those in a more masculine blue color to suit the rest of us?

lol

normalicy · Post by **normalicy** » Mon May 11, 2015 8:58 pm

Occasional use is like every 6 months. I rarely use my laptop.

Post by **FlyingPenguin** » Thu May 14, 2015 8:02 am

And AnandTech calls "bunk" on the numbers in that article.

While temperature is the major factor (like a hot car in the summer), under normal room temperatures, SSDs should retain data for several years.

All in all, there is absolutely zero reason to worry about SSD data retention in typical client environment. Remember that the figures presented here are for a drive that has already passed its endurance rating, so for new drives the data retention is considerably higher, typically over ten years for MLC NAND based SSDs. If you buy a drive today and stash it away, the drive itself will become totally obsolete quicker than it will lose its data. Besides, given the cost of SSDs, it's not cost efficient to use them for cold storage anyway, so if you're looking to archive data I would recommend going with hard drives for cost reasons alone.

The Truth About SSD Data Retention
http://www.anandtech.com/show/9248/the- ... -retention

Post by **FlyingPenguin** » Thu May 14, 2015 11:11 am

Steve Gibson also mentioned at the start of this week's podcast, that he doubts about the conclusions of the original article.

Haven't heard the whole podcast yet. He's going to go over it in more detail later.

Executioner · Post by **Executioner** » Thu May 14, 2015 1:38 pm

Good to know. Thanks

Pugsley · Post by **Pugsley** » Thu May 14, 2015 7:20 pm

I have a SSD in one of my pinball machines and I thinks it's been a year since I last powered it up to work on it. It started with no computer related problems... but still has pinball problems.

renovation · Post by **renovation** » Fri May 15, 2015 12:10 am

come on guys we all know the best place to keep all are valuable data is still on a floppy disk. 5 in or 3 1/2 size in a dusty damp hot sauna .

Pugsley · Post by **Pugsley** » Fri May 15, 2015 6:00 am

I personally use tape backups... Punch tape that is!