Storelab, a Russian player in data recovery, recently released a long-term study comparing hard drives from a number of different vendors. The controversial report offers interesting data and provides a snapshot of HDD reliability and defect reasons.
The Durability Standard
The majority of all hard drives sold worldwide are produced by just six manufacturers: Fujitsu/Toshiba, Hitachi, Samsung, Seagate, and Western Digital. In order to determine which of these vendors sell the most durable products, Storelab evaluates the hard drives they receive for recovery, as well as the economical losses failures cause customers. In this particular study, more than 4000 2.5" and 3.5" hard drives are included. Storelab also compares the number of defective drives received by different manufacturers with their respective market shares. One has to keep in mind that failure rates will appear higher for popular manufacturers. A substantial difference between market share and the proportion of failed drives can indicate higher or lower product durability.
At this point, we also need to make very clear that the study is not representative and cannot be seen as a comprehensive reliability summary. It reflects only a very tiny fraction of the hard drive market. Drives are taken from analysis made during the recovery process, and there aren't specific test groups. It covers different form factors and different product lines, etc. Think of this analysis as an overview on reliability that might apply to the hard drives in your home city. Results very likely differ somewhere else.
Based on the graphs, we see that failures and market shares only partially correlate. The largest percentage difference can be seen with the market leader, Seagate, where its failure rate of over 56% is almost twice as high as its 31% market share. Even though Seagate reports a 40% market share within the Russian market, from which Storelab pulls its data set, the difference is still very noticeable. The other five manufacturers show proportional failure rates below their market shares. In particular, Hitachi and Western Digital are almost 11% lower, at least suggesting higher durability and reliability. Again, this only applies to this limited sets of drives in this specific environment.
The second key durability indicator is the average age of hard drives at their time of failure. Again, we see large differences between the various manufacturers, as well as between specific models. A hard drive's future durability is difficult to predict during development. Engineers cannot do much more than perform laboratory tests and simulate the effects of temperature, pressure, vibration, etc. These setups are never capable of identifying all possible design flaws, especially since the tests cannot be run for the full time periods the drives are designed to operate. Instead, a failure-free test period of around one and a half years is considered a good enough yardstick for the durability of the hard drive's design and construction.
As you can see from the Storelab-provided table (complete with Russian titles), Hitachi wins in terms of long-term reliability for 500 GB models. These drives operated for an average of five years, at least half a year longer than those of Western Digital. The values for Seagate's 7200.10- and 7200.11-series were separated to give a more fair representation. Keep in mind that a new product line can potentially turn the results upside down. We're looking at a snapshot of the hard drive market last year.