How Long Can Data Stay on a Hard Drive?

Though hard drive technology has progressed significantly in recent decades, there are still limitations to how long hard drives can run efficiently and store data before failing. Barring sudden failures or other unfortunate circumstances, the vast majority of drives will run for at least four to five years with steady use. Hard drives kept in storage will last even longer, though they can still fail even when not in use.

Hard drives are delicate pieces of technology, and many things can cause them to fail. Constant exposure to excess heat or cold, moving the hard drive while it is operating and power failures or surges can all contribute to shortening a hard drive’s life. Constant use of a disk can also influence this, especially if you write and rewrite great amounts of data at once. Constant writing of data will wear down a hard drive faster than using it for simple storage.

Solid-state drives are a newer type of hard drive that uses flash memory instead of moving parts like HDDs. SSDs are more expensive and can’t hold as much data, but they are faster than HDDs. Despite not having any moving parts, they can have problems of their own: Andrew Ku of Tom’s Hardware performed a study of more than 160,000 SSDs to assess their length of life and failure rate. The study showed that they do not have a distinct advantage over HDDs in terms of longevity of data or reliability. If you’re trying to figure out which is better to store data on long term, either will work as long as you are careful.

Even in otherwise perfect conditions, hard drives wear down over time as data is written and rewritten. A study of 25,000 hard drives by the online backup company Backblaze found that almost 80 percent of hard drives operating under constant use survive at least four years. An unused hard drive will last far longer and can keep data for up to many decades under optimal storage conditions. Data can fade over time from hard drives in storage due to the gradual fading of the drive's magnetic domains. This problem can be mitigated by rewriting the hard drive's data every few years; to do this, simply transfer the drive's contents to another location and then put them back on the drive.

Due to the sheer amount of variety of hard drives in terms of make, quality, storage size and design, it’s difficult to be more than vaguely specific as to how long your specific hard drive will last. High-quality hard drives will tend to be more reliable, and the storage capacity of your drive has little to do with how long it will last. Regardless of the type of hard drive you use, constant backups to multiple locations are still the most reliable way to keep your data safe.