We often get asked from clients about the reliability of their hard drives.  We obviously tend to see the those that fail and there is no shortage of those.  However, what are the odds of your Hard Drive failing?  Is reliability getting better or worse? Are some Drives simply more reliable than others?  Or, are SSD's (Solid Sate Drives) just better, full stop? 

Either way we felt it useful to give some indicators to our clients.

We see Hard Drives that fail for all sorts of reasons.  Some are simply the result of accidents that they were never designed to cope with.  We have undertaken data recovery on; laptops with Hard Drives that have been in car crashes, Drives that have been picked out of fire damaged buildings and even ones retrieved from the seabed.  However, if we exclude those that are the result of a severe external physical shock.  Then how reliable is the typical Hard Drive for storing your data?

One useful measure of reliability is provided by Blackblaze a Data Centre provide. They are fairly unique in that they publish their Hard Drive failure rates. With (as at Sept 2018) some 99,636 drives. Using the ones that are most reliable is clearly very important to their business. However, before we get into the stats, it is important to note that Data Centres, like Backblaze, do tend to use the larger capacity drives. Ones designed for professional IT data Centre use. Their drives are also held in what are, ideal conditions to maintain maximum reliability and clearly they don't get subjected to the shocks that you would get in e.g. a laptop being dropped. They can thus, be expected to be more reliable in use than your typical laptop Hard Drive. So, this said what are the results?

Failure Rates

Their latest overall lifetime failure rate is 1.71% (their best ever failure rate). This means that, over a five year period they expect just less than 1 in 50 of their Hard Drives to fail.   Their evidence also suggests that over time drives are  getting ever so slightly more reliable - as a general trend. 

However for a typical laptop or PC user, or someone using an external Hard Drive.  We would suggest the odds of a failure will be higher than the 1 in 50 suggested above. Another factor to consider, is that there is evidence that failure rates can increase over time.  What this means is that the longer you use a drive the greater the tendency for it to fail. A good analogy is, it's a bit like running a car. You can get problems in the first few years. But the longer you keep it the more prone it will be to breaking down. Sadly, unlike a car, Hard Drives can only vary rarely be repaired. Fortunately, they most likely can have their data recovered and out Lab technicians have been successful in getting data back with even very damaged drives.


So, where does this leave us? The point of this post is not to put you off Hard Drives.  For large data storage they are still be the most cost effective and practical means of storage. There is a general trend towards SSD's. We plan to do a post on them at a later date.  However, we are seeing quite a few SSD failures in the Lab too. As they become more popular there will be more information available on their reliability performance.  However they are sadly not 100% reliable and they do fail too, especially over time.

Our best advice is for you not to buy simply on price.  Stick with the well-known established brands. Backup your data, and to two or more places. Lastly if you have data on a drive that fails, call us.  Don't try and take the drive apart or - we respectfully suggest - attempt a DIY hardware or software repair. Our assessments are free and are a much better first point of call.