So to sum up the data, it sounds like:

• WD seems to have the most reliable drives of those tested, with Toshiba being a relatively close second
• Some models of drives are significantly more likely to fail than others, with some having a ~6% annual failure rate vs another model from the same company at 1%
• Seagate had a rough year when it comes to reliability
• It’s hard to tell if capacity affects drive life as the drives being tested have been in use for different lengths of time