Hard Drive Reliability Stats for Q2 2015 July 28, 2015 byAndy Klein // 137 Comments For the most recent hard drive reliability statistics, as well as the raw hard drive test data, visit Hard Drive Data and Stats. Each quarter, Backblaze updates our hard drive statistics with the latest data. As of the end of Q2 2015, there were 47,561 drives spinning in our data center. Subtracting out boot drives