SSDs are fairly new to the market, meaning manufacturers are still trying to figure out how long they will last. Currently, vendors use three different factors to estimate SSD lifespan: the age of the SSD, the total number of terabytes written over time (TBW), and the drive writes per day (DWPD). Based on which metric you use, the answer to the question “How long do SSDs last?” will vary.
For example, the age of an SSD has proven to be a valuable determinate in its performance and longevity. Current estimates put the age limit for SSDs around 10 years, though the average SSD lifespan is shorter. In fact, a joint study between Google and the University of Toronto tested SSDs over a multi-year period. During that study, they found the age of an SSD was the primary determinant of when it stopped working. Researchers working on the study also found SSDs were replaced about 25% less often than HDDs.
Another way of measuring how long SSDs will last is the total number of terabytes written over time (TBW). TBW estimates how many successful writes you can expect a drive to make over its lifetime. If a manufacturer says their SSD has a TBW of 150, it means the drive can write 150 terabytes of data. After the drive hits that threshold, it’s likely you’ll need to replace it.
The final of the three metrics manufacturers might use when predicting the lifespan of their drives is the drive writes per day (DWPD). DWPD measures how many times users can overwrite the amount of available storage in the drive each day of its working lifespan. If an SSD has a capacity of 200 GB and comes with a five-year warranty, for instance, users can write 200 GB onto the drive every day for the warranty period before it fails. When in doubt, you can use an online SSD lifespan calculator to estimate the SSD’s lifespan.
Do SSDs fail?
SSDs can fail, but in a different way than traditional HDDs. While the latter often fail because of mechanical issues, SSDs may fail due to the methods used to write information. To understand why and how SSDs fail, it’s important to understand more about the way they process, store, and access information in the first place.
As previously mentioned, SSDs use flash memory cells to store data. In this way, SSDs function almost like large flash drives, programming data onto these cells by changing their electric charges. However, once you fill the available memory on an SSD, the SSD can only add new information by erasing older data. This process is called a program/erase cycle, or P/E cycle for short.
Importantly, each SSD has a limited number of P/E cycles. Each P/E cycle gradually degrades the memory of an SSD’s cells until they eventually become worn down. At this point, you will no longer be able to rely on the SSD to store information. While the gradual wearing out of SSD flash cells doesn’t represent the same kind of failure as a mechanical malfunction on a HDD, it does mean the drive will no longer be usable.
While SSDs may fail with less frequency than HDDs, they do have a higher error rate that can affect the end-user experience. For example, so-called uncorrectable errors are relatively common in SSDs. Research shows that over 20% of SSDs develop uncorrectable errors over a four-year period, and 30% to 80% develop bad blocks. All of these errors can affect data retention and lead to effective failure.
Which lasts longer: SSDs or HDDs?
Whether you’re looking to invest in new storage hardware for your own MSP or your customers, it helps to understand the relative advantages and disadvantages of SSDs and HDDs. While the right option will vary depending on several variables such as your budget, the nature of the work you do, and how much wear and tear you expect to put on your drives, both can be viable options for companies in a wide range of industries.
For instance, HDDs might not be cutting-edge technology, but they have their benefits. They’ve been around for decades, meaning tech professionals are very familiar with how they work. By contrast, experts are still learning how SSDs function in the long term. Additionally, HDDs are more affordable than SSDs and tend to offer larger amounts of storage per model. These benefits mean that HDDs are cost-effective and generally a viable option for many businesses.
However, HDDs also come with their own drawbacks. Because they depend on physical moving parts, they’re susceptible to damage and malfunction in ways SSDs aren’t. Dropping a device with an HDD can cause any number of these parts to break, rendering the drive inoperable—and making any information stored on the HDD especially difficult to retrieve. Finally, HDDs are larger and use more energy as compared to SSDs. This presents design challenges, especially with mobile devices such as laptops.
Conversely, SSDs offer their own unique set of considerations for businesses. SSDs have lots of benefits—for starters, SSDs tend to deliver faster performance because of the way they process, store, and access data. This can be especially useful when it comes to complex business applications that may otherwise take a longer time to load. Beyond that, SSDs weigh less, aren’t as energy-intensive as HDDs, and are more durable because they lack the fragile moving parts associated with HDDs.
While SSDs do come with potential disadvantages, manufacturers are working to improve the technology. As discussed earlier, once SSDs are full, they can only write new information by erasing older information. Over time, this creates wear and tear on flash cells and ultimately renders them unusable. However, many SSDs are beginning to use wear-leveling algorithms to ensure space is being used as effectively as possible.
In short, the respective lifespan of SSDs and HDDs will change depending on how you use them. While HDDs may nominally offer more storage space than most SSD models, they’re more fragile because of their moving parts and are susceptible to damage. On the other hand, each P/E cycle degrades the SSDs, meaning there is a definite point when the SSD will no longer work.
If you’re looking for new storage solutions, make sure you’re equipped with the information you need to make the right decision.
For more information on SSD drives and how to use them effectively, head to our blog for articles on the topic.