Under normal conditions, your average Solid State Drive (SSD) will last many years before failing. You’ll likely be replacing other components, like your GPU or CPU, that have gone out of date long before your SSD died.
When large-scale flash storage first hit the consumer market as an alternative to conventional hard drives, the biggest concern (aside from price) was longevity. Tech geeks had a pretty good idea of the general reliability of hard drives, but solid-state drives (SSDs) were still something of a wild card.
SSD Lifetime Basics
Now, the SSD market has matured considerably, and we have a lot more data about… well, data. The good news is that SSDs have proven to be extremely reliable and certainly at least as good as hard drives in terms of data retention and failure rates. The bad news is that SSDs tend to fail more often over time, and not with extended data reading and writing, as previously predicted.
That means you’re no more likely to lose data with an all-flash setup compared to a standard hard drive, but it’s still essential to keep important files backed up.
Before moving on to some of the testing, it’s important to get a quick introduction to some of the more technical terms associated with SSDs:
- MLC and SLC: Multi-level cell memory is cheaper and slower, usually found in consumer grade SSDs. Single-level cell memory in enterprise and enthusiast grade SSDs is faster and technically less prone to data loss.
- memory blocks: A portion of physical memory on a flash drive. A “bad block” is inaccessible or poorly accessible to your computer, resulting in a lower than reported level of available storage and possible read and write errors for files and software.
- TBW: Terabytes Written. The total amount of data written and rewritten to a drive during its lifetime, expressed in terabytes.
With that in mind, let’s answer this question.
How long do SSDs last?
Your typical SSD will survive many years of typical home use before it is at considerable risk of failure. The exact duration depends largely on the amount of data being written to the drive, as well as the age of the drive and environmental conditions. Anecdotally, asking around the How-to Geek office, none of us have ever had a dead SSD, and we’re putting far more miles on our computer components than the average person. But aside from the anecdotes, what does the data say about how long your fancy new SSD will last?
SSD vendors tend to rate the reliability of their drives on three factors: standard age (like any warranty), total terabytes written over time, and the amount of data written to the drive per specified period of time, such as one day. . Obviously, measurement against these three different standards will yield different results depending on the methodology. And the very fact that there are three extremely flexible standards for “wear” in a digital component should illustrate something to the end user: Precisely predicting how long it will take for a specific SSD to fail is more or less impossible. We can only give a very vague point of the maximum possible data retention, after which use of the drive will put you in danger of immediate loss of data and computer operation.
SSD Lifetime Studies
There have been several studies attempting to determine a more accurate lifespan for solid state memory. Some of the best known include:
A joint study between Google and the University of Toronto covering drive failure rates in data servers. The study concluded that the physical age of the SSD, rather than the amount or frequency of data written, is the primary determinant of the likelihood of data retention errors. It also found that SSDs were replaced at Google data centers much less frequently than conventional hard drives, at a ratio of about one to four. But it wasn’t all positive in favor of SSDs: They experienced higher numbers of uncorrectable errors and bad blocks at a much higher rate than hard drives during the four-year test period. conclusions: In a high-stress, fast-read environment, SSDs will last longer than HDDs, but will be more susceptible to non-catastrophic data failures. Older SSDs are more prone to complete failures, regardless of TBW or DWPD.
The Tech Report’s study on longevity among major brands. Among the six SSD brands tested, only the high-end Kingston, Samsung, and Corsair drives managed to survive after writing more than 1,000 terabytes of data (one petabyte). The other drives failed between 700 and 900 TBW. Two of the failed drives, Samsung and Intel, used the cheaper MLC standard, while the Kingston drive is actually the same model as the one that survived, just tested with a similar methodology. conclusions: A ~250 GB SSD can be expected to die sometime before a petabyte is written; although two (or perhaps three) of the models exceeded that mark, it would be smart to plan for a contingency in case your specific drive underperforms, even if you use more expensive SLC memory.
Higher capacity SSDs, because they have more sectors available and more “space” to use before failing, should predictably last longer. For example, if a 250GB Samsung 840 MLC drive fails at 900TBW, it would be reasonable to expect a 1TB drive to last considerably longer, if not necessarily up to a whopping 3.6 petabytes written.
Facebook publicly published an internal study (PDF link) of the lifespan of SSDs used in its corporate data centers. The findings focused on the environmental conditions of the data centers themselves; for example, they came to the fairly obvious conclusion that prolonged proximity to high temperatures was hurting the lifespan of an SSD. But the study also found that if an SSD doesn’t fail after its first major detectable errors, it’s likely to last much longer than overly cautious software diagnostic software. Contradicting Google’s joint study, Facebook found that higher data write and read rates can significantly affect a drive’s lifespan, though it’s unclear whether the latter was controlling the drive’s physical age. conclusions: Except in cases of early total failure, SSDs are likely to last longer than indicated by initial errors, and data vectors such as TDW are likely to be overestimated by software measurement due to system-level buffering .
Of course, all of those studies look at intense data center applications. The average home user won’t come close to that kind of utilization.
Backblaze, a cloud storage and computer backup company, has been conducting a study comparing SSDs and HDDs as boot drives for their servers. It’s closer to the stress that an average user might put on their drives. His study is simple: How many boot drives die per year? What is the annualized failure rate of HDD vs. SSD? Conclusions: Hard drives and solid state drives will die at a similar rate during the first 3 years of operation, but after that, the failure rate of hard drives begins to rise rapidly, while the failure rate of solid state drives remains fairly constant for at least 5 years. It’s not yet clear whether or not SSDs will hit a “wall of failure” – an age at which many drives start to fail spontaneously – however, you can probably count on your drive to work for at least least 5 years.
Why you don’t need to worry
Taking all these data at once, what general conclusion can we draw? Looking at these studies back to back, you might be worried that your SSD will catch fire after a year or two. But keep in mind that two of the studies were done in enterprise-class data centers, reading and writing data more or less constantly every day to years, and the consumer-focused study was conducted specifically for test drives with constant use. To reach a petabyte of total written data, the average consumer would have to use their computer non-stop for a decade or so, maybe even several decades. Even gamers or “power users” will probably never reach the stated maximum amount of data written for a drive under its warranty. Backblaze’s review, which is closer to normal use, paints a more rosy picture: Most of its drives perform well after five years of use in a professional environment.
In other words: You’ll probably upgrade your entire computer before your SSD fails.
Now, it’s still possible for the electronics in your SSD to fail, just like any part of the computer. And the likelihood of your SSD experiencing data retention failure increases the longer it’s used. Since that is true, it is always advisable to keep a backup of your critical data on an external drive and (if possible) in a remote location as well. Just remember to plug in your SSD regularly if you’re using it for long-term storage. But if you’re worried your SSD will fail at any moment or be less reliable than your trusty old hard drive, don’t.