How Long Will SSDs Last?
A solid state drive doesn’t contain the moving parts of a hard drive. The spinning platter (the disk), the arm and magnetic head are absent, and flash chips are used in their place.
This means an SSD is not vulnerable to head crash in the way that a hard disk is. The added durability gives the SSD an obvious reliability advantage, especially when it comes to shock or exposure to less than optimum environmental conditions. They’re also not affected by magnets.
However, it should be remembered that the other components in an SSD are the same as those in a hard drive, and are no more or less likely to fail. SSDs are also extremely susceptible to power failure, leading to corruption of data or even the failure of the drive itself.
With solid state drives still being in their relative infancy, it will likely be a few more years before we get a true picture of how well they hold up to repeated use.
The lifespan of each memory block in an SSD is limited to a certain number of write cycles i.e. the number of times a piece of data can be stored to it.
The number of cycles will only be a few thousand on most drives. This sounds alarmingly low, but is not really an issue in modern SSDs. Unlike hard drives, which write their data to the earliest free block, an SSD uses technique called wear-levelling to ensure that each memory block is used before the cycle begins again at the first block.
Unless you’re writing tens of gigabytes of data a day, every day for several years, you won’t get close to the limit on write cycles. Even if you did, the memory would become read-only, so your data would still be accessible.
All this means that SSDs are a great choice for day-to-day storage over HDDs, so long as performance is bigger priority than capacity, given the relatively higher price of a solid state drive.
An SSD is not a good option for long-term storage, though.
How long an SSD can store data without power depends on a number of factors including the number of write cycles that have been used, the type of flash memory used in the drive, the storage conditions and so on. A white paper produced by Dell in 2011 (PDF link) stated that it could be as little as three months to as much as 10 years.
Many SSD manufacturers will list data retention either as part of the specification or the warranty for their drives. The JEDEC Solid State Technology Association sets the industry standard at one year for consumer drives.