Can SSDs Lose Data Without Power?

To some people, solid state drives (SSDs) represent a new long-anticipated era in storage technology that is taking us leaps and bounds forward. To others, SSDs represent a shaky technology that doesn’t live up to its expectations and can fail at any moment. Both of these statements aren’t necessarily false, since this storage technology is relatively new but at the same time has some flaws that make people think twice about purchasing these drives for themselves. A new report from the Joint Electron Device Engineering Council (JEDEC) adds another concern about SSDs: They possibly will not be able to retain their storage over long periods of time without power. Is this true? And what can you do about it?

The boot process in your computer, in its simplest form, grabs your operating system from your storage and writes it into RAM memory. The reason your computer has to go through the boot process all over again once you cut off the power is because RAM cannot retain data without power. That said, SSDs operate with chips that are similar to RAM (hence the term “solid state”; there is no moving parts). The concern of a loss of data is realistic if you think of it in this context. However…

SSDs operate with chips that are similar to RAM.

SSDs don’t use RAM chips. They use NAND flash chips which have different gateway wiring that retains its state even after the power is cut off. Flash memory has a special feature called a “floating gate” which is electrically isolated. Because of this isolation, there are (theoretically) no conventional external influences that can immediately change its state. That’s what makes it a viable long-term storage device.

The report from JEDEC, however, tells us that the temperature in which the device is stored when it is inactive (no power flows through it) can lower the lifespan of the data inside of it. The report suggests that the two-year ideal storage lifespan of an SSD is only available at a maximum long-term storage temperature of 25 degrees Celsius (77 degrees Fahrenheit). Bump the temperature up by five degrees Celsius, and you have effectively halved the lifespan to one year.

In general, I’d think you’d be using your SSD on a semi-regular or daily basis, right? If you want to store it for a long time, you should already be storing it in a comfortable temperature range for less than two years (who sets that kind of hardware aside that long?). This is already starting to look like it isn’t much of a concern.

Samsung 316 RAM chip.

In addition to this, the language of the study suggests that the predictions are at least quasi-theoretical. The methodology isn’t described very clearly, and there is no indication of how many drives were tested. The report’s conclusion is that “different temperatures introduce different NAND failure mechanisms.” In laymen’s terms, this means that they acknowledge that temperature does influence how long you can keep your data when the SSD is unpowered. Just how long that is, as with any other flash memory, depends on the drive itself.

Yes, maybe there is a concern. This article isn’t meant to bash the report. Its conclusion is speculative but still important. Ideally, you should be treating your SSD well and keeping it in a low-temperature area. Otherwise, just use it. If you want to store something that can stay in a long-term unpowered state, use a mechanical hard drive. These are very common sense suggestions. For the amount of time SSDs have been around, as of 2015, their limitations are still not completely discovered, and the JEDEC report is a good step in the right direction.

If you have any other questions about SSDs, please address them in the comments!