i think this worth to note *based what i search, so feel free to cmiiw those HGST drive HMS5C4040ALE630/ALE640/BLE640 is MEGASCALE / CoolSpin line up basically enterprise / DC model hdd consumer NAS model is HDN7240******** / HDN7260******** source: https://www.hgst.com/sites/default/files/resources/DS_NAS_ds.pdf i know back google hdd reliability paper said enterprise and consumer hdd reliability is not much different, but the table and what backblaze saying can a bit missleading as like in table : toshiba MD04ABA***V is surveilance HDD WD40(30)EFRX this is WD RED not even PRO version which model type should end with FFWX, not even gold (****FRYZ) what i am trying to say, backblaze table didn't using same class/work-rate hdd so i wonder if the table have really meaning / proving failure-rate as if some model have higher failure rate, it can be because the hdd not designed as server workload

Yup that the whole problem with Backblaze the 4TB HGST is a Enterprise Hard Drive not Retail or OEM that why look they so good you pay out nose for them so I say over there nothing wrong with Seagate sure just any other drive that can go bad just like SSD Seagate ST?000DM00? - Consumer OEM drive Seagate ST?000AS00? - Consumer Retail Seagate ST?000NM000? - Enterprise drive

In Backblaze environment Seagate's Enterprise disks are not doing any better than consumer disk. I suspect same might be true for WD/WD pro. I am thinking Enteprise/consumer are physically the same.