3TB had a failure rate of 3.63% out of 978x drives. In Q4 2016, the WDC 3TB had a 3.28% failure rate out of 1105x drives, while the HGST HDS72. In the 2015 test for example, 1046x WDC WD30EFRX 3TB drives had a 7.27% failure rate while 1000x HGST HDS723030 3TB drives had a 1.80% failure rate.
Backblaze has other test years too with more WD vs HGST and Toshiba harddrives.
